JP2008094623A - Safety device for mobile crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device for a mobile crane enabling improvement of operability and safety of crane work by preventing difficult danger prediction of an operator due to difference of operating radius from warning to automatic stop due to difference of crane attitudes and difference of operating radius even in a same crane attitude, and preventing load swing due to quick stop of the crane. <P>SOLUTION: The safety device 20 provided with a control device 30 which operates a relation or the like between lifting load and capacity according to working conditions from quantities of states of every elements input from a boom angle meter 21, a load meter 22, and a boom length meter 23, and quantities of states of establishment of the crane, and which automatically stops the crane when load rate L reaches 100%, is provided with a prediction information means informing prediction based on that the operated load rate L reaches prediction information load rate L<SB>A</SB>calculated according to operating radius R of the lifting load and operating radius ratio α which is a ratio of a rated operating radius R<SB>S</SB>to the lifting load. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement in the safety device of a mobile crane. More specifically, even if the crane position is different and the crane position is the same, the operator's risk due to the difference in actual work radius from forecast to automatic stop due to the difference in actual work radius. The present invention relates to a safety device for a mobile crane that makes it possible to improve the safety of crane work by preventing difficulty of prediction and swinging of a load due to a sudden stop of the mobile crane.

  For mobile cranes, an overload prevention device (hereinafter referred to as a safety device) should be installed as a safety device to prevent the mobile crane from being damaged or toppled when the lifting load exceeds the rated load. Mandatory. For safety devices, there are alarm types and automatic stop types, but both calculate the load factor, which is the ratio of the lifting load and the rated load, and predict when the load factor exceeds a certain value during crane operation. To notify the operator, and when the load factor reaches a predetermined ratio (for example, 100%), the mobile crane is automatically stopped or an alarm sound is generated. As a safety device for a mobile crane according to such a conventional example, for example, a device having a configuration described later is known.

Hereinafter, the outline | summary of the safety device of the mobile crane which concerns on a prior art example is demonstrated. That is, in the mobile crane safety device according to this conventional example, the timing for notifying the forecast is changed depending on the working state of the mobile crane and individual differences among operators. More specifically, by calculating the margin angle Δθ up to the boom angle θ _S that automatically stops for each actual load W _L (W ₁ , W ₂ , W _3. The boom angle θ _A to be notified is obtained from the formula θ _A = θ _S + Δθ, and the timing for notifying the forecast is changed by the boom hoisting speed. Of course, when the load factor L (= W _L / W × 100) reaches a predetermined ratio (for example, 100%), the mobile crane is automatically stopped by an operation stop command signal from the safety device (for example, a patent) Reference 1).
JP-A-7-89694

  The lifting capacity of a mobile crane is generally determined by the crane attitude (boom length, boom hoisting angle, crane stability based on the distance between the outermost sides of the left and right crawlers, or the distance between the load application points of the left and right outriggers. Various cranes are set depending on the crane stability and the like, and the lifting ability in each crane posture is different. In addition, in a mobile crane, the rate of increase / decrease of the rated load with respect to the actual working radius is not constant. Furthermore, even if the crane posture is the same, the rate of increase / decrease in the rated load is not constant depending on the actual work radius. Nevertheless, because the forecast is calculated based on the load factor based on the rated load with a constant increase / decrease ratio, the forecast is reported depending on the size of the actual work radius for each crane position or the same crane position. As a result, the actual working radii are different until the mobile crane stops automatically (the warning may be issued after the forecast is notified).

  The operator generally predicts the actual working radius at which the mobile crane automatically stops due to the change in the actual working radius from when the forecast is reported until the mobile crane automatically stops. In the calculation of the load factor based on the ratio, it is very difficult to predict the danger because the actual work radius differs for each crane posture. In addition, if the actual work radius margin from when the forecast is announced until the mobile crane stops automatically is small, the mobile crane will suddenly stop and the load will sway and the mobile crane will automatically stop. However, the danger level may increase. Moreover, even if the timing for notifying the forecast is changed as in the above-described conventional example, the actual work radius from the forecast to the automatic stop due to the change in the crane posture is not different, and similarly dangerous. It is difficult to predict, and it is difficult to avoid the occurrence of cargo swing due to a sudden stop of a mobile crane.

  Therefore, the object of the present invention is that it is difficult for the operator to predict the danger due to the difference in the actual work radius from the forecast to the automatic stop due to the difference in the actual work radius even if the crane posture of the mobile crane and the crane posture are the same. It is to provide a safety device for a mobile crane that makes it possible to improve the safety of crane work by preventing the swinging of the crane due to a sudden stop.

  In order to solve the above problems, the means adopted by the mobile crane safety device according to claim 1 of the present invention is a load detecting means for obtaining an actual load of a suspended load suspended from the tip of the boom, and a boom. Boom length detection means for detecting the length of the boom, and at least three or more types of detection means including boom angle detection means for detecting the undulation angle of the boom, and the detection results of the boom length detection means and the boom angle detection means Working radius calculating means for calculating an actual working radius based on the above, a rated working radius calculating means for calculating a rated working radius corresponding to the actual load of the suspended load, and a first margin of the actual working radius with respect to the rated working radius. A first margin calculating unit for calculating, a forecast determining unit for determining whether or not the vehicle is in an overload forecast state based on the first margin, and determining that the forecast determination unit is in an overload forecast state. A rated notification state for calculating a rated state quantity relating to a predetermined state quantity obtained from a detection result of at least one of the detection means A quantity calculating means, a second margin calculating means for calculating a second margin of a predetermined state quantity with respect to the rated state quantity, and whether or not an overload state is established based on the second margin. An overload determination means for determining, and a risk avoidance control means for performing risk avoidance control when it is determined that the overload determination means is in an overload state, and the risk avoidance from the notification of the forecast by the forecast notification means The change amount of the actual work radius until the execution of the danger avoidance control by the control means is configured to be a predetermined amount.

  The safety device for a mobile crane according to claim 1 of the present invention is configured such that the amount of change in the actual work radius from the prediction notification by the prediction notification means to the execution of the risk avoidance control by the risk avoidance control means becomes a predetermined amount. Therefore, when the amount of change in the actual work radius reaches a predetermined amount, a forecast is notified from the forecast notification means. Therefore, according to the mobile crane safety device of the first aspect of the present invention, the amount of change in the actual work radius from when the forecast is notified until the risk avoidance control by the risk avoidance control means of the mobile crane is executed. Is known to be the predetermined amount, the operator can stop the operation of the mobile crane with a margin, and the risk avoidance control by the risk avoidance control means of the mobile crane, for example, automatic stop is avoided, and the mobile Since it is possible to prevent the swinging of the crane due to the sudden stop of the crane, it can greatly contribute to the improvement of safety in the crane operation.

  The means adopted by the mobile crane safety device according to claim 2 of the present invention is the mobile crane safety device according to claim 1, wherein the first margin is a ratio of the actual work radius to the rated work radius. And the forecast determination means is based on whether or not the second margin has reached a forecast allowance of a second margin preset according to the task radius ratio. It is characterized by determining whether it is an overload forecast state.

According to the safety device for a mobile crane according to claim 2 of the present invention, according to the work radius ratio, the second margin is the ratio of the actual work radius R to the rated work radius R _S by the forecast determination means. It is determined whether or not an overload prediction state is reached based on whether or not a preset second tolerance forecast allowable value has been reached. And if it is an overload forecast state, a forecast will be reported from the forecast reporting means, but the amount of change in the actual work radius from when the forecast is reported until the risk avoidance control by the danger avoidance control means of the mobile crane is executed Is known to be the predetermined amount, the operator can stop the operation of the mobile crane with a margin, and the risk avoidance control by the risk avoidance control means of the mobile crane, for example, automatic stop is avoided, and the mobile Since it is possible to prevent the swinging of the crane due to the sudden stop of the crane, it can greatly contribute to the improvement of safety in the crane operation.

  The means adopted by the mobile crane safety device according to claim 3 of the present invention is the mobile crane safety device according to claim 1, wherein the first margin is a ratio of the actual work radius to the rated work radius. The work radius ratio is determined based on whether the work radius ratio has reached a forecast allowable value of the work radius ratio set in advance according to the predetermined state quantity. It is characterized by determining whether it is a forecast state.

  According to the safety device for a mobile crane according to claim 3 of the present invention, the work radius ratio, which is the ratio of the actual work radius to the rated work radius, which is the first margin, is determined by the forecast determination means. Whether or not an overload forecast state is established is determined based on whether or not the forecast allowable value of the work radius ratio set in advance is reached. And if it is an overload forecast state, a forecast will be reported from the forecast reporting means, but the amount of change in the actual work radius from when the forecast is reported until the risk avoidance control by the danger avoidance control means of the mobile crane is executed Is known to be the predetermined amount, the operator can stop the operation of the mobile crane with a margin, and the risk avoidance control by the risk avoidance control means of the mobile crane, for example, automatic stop is avoided, and the mobile Since it is possible to prevent the swinging of the crane due to the sudden stop of the crane, it can greatly contribute to the improvement of safety in the crane operation.

  The means adopted by the mobile crane safety device according to claim 4 of the present invention is the mobile crane safety device according to claim 1, wherein the first margin is the difference between the rated work radius and the actual work radius. Whether or not the work radius difference is an overload prediction state based on whether or not the work radius difference has reached a preset work radius difference forecast allowable value. It is characterized by determining.

  According to the safety device for a mobile crane according to claim 4 of the present invention, the work radius difference that is the difference between the rated work radius that is the first margin and the actual work radius is set in advance by the forecast determination unit. It is determined whether or not an overload prediction state is established based on whether or not a work radius difference forecast allowable value has been reached. And if it is an overload forecast state, a forecast will be reported from the forecast reporting means, but the amount of change in the actual work radius from when the forecast is reported until the risk avoidance control by the danger avoidance control means of the mobile crane is executed Is known to be the predetermined amount, the operator can stop the operation of the mobile crane with a margin, and the risk avoidance control by the risk avoidance control means of the mobile crane, for example, automatic stop is avoided, and the mobile Since it is possible to prevent the swinging of the crane due to the sudden stop of the crane, it can greatly contribute to the improvement of safety in the crane operation.

  The means adopted by the mobile crane safety device according to claim 5 of the present invention is the mobile crane safety device according to claim 1, wherein the forecast determination means is a ratio of an actual work radius to a rated work radius. Predetermined forecast allowance for second margin according to a certain work radius ratio, forecast allowance for work radius ratio preset according to a predetermined state quantity, preset work radius and actual work Among the three first margins of the second allowance, the work radius ratio, and the work radius difference corresponding to these three forecast allowances It is characterized in that it is determined whether or not the overload forecast state is based on the first margin that has reached the corresponding forecast allowable value for the first time.

  According to the safety device for a mobile crane according to claim 5 of the present invention, the forecast determination means includes the forecast allowance for the second margin, the forecast allowance for the work radius ratio, and the forecast allowance for the work radius difference. Among the three first margins, the second margin, the work radius ratio, and the work radius difference corresponding to these three forecast tolerances, the first forecast margin that has reached the first forecast tolerance is Based on the margin of 1, it is determined whether or not it is an overload prediction state. Therefore, since the forecast is notified on the safety side of any of the mobile crane safety devices according to claims 2 to 4 above, the safety of the mobile crane in the crane work is excellent.

  In the mobile crane safety device of the present invention, the amount of change in the actual work radius from the notification of the forecast by the forecast notification means to the execution of the risk avoidance control by the danger avoidance control means is configured to be a predetermined amount. When the amount of change in the actual work radius reaches a predetermined amount, a forecast is notified from the forecast notification means.

  Therefore, according to the mobile crane safety device of the present invention, the predetermined amount of change in the actual work radius from when the forecast is notified until the risk avoidance control by the risk avoidance control means of the mobile crane is easily performed. Therefore, the operator can stop the operation of the mobile crane with a margin, the risk avoidance control by the risk avoidance control means of the mobile crane, for example, automatic stop is avoided, and the load is not shaken by the sudden stop of the mobile crane. Since it can prevent, the outstanding effect that it can contribute greatly with respect to the safety | security improvement in a crane operation | work can be acquired.

Hereinafter, the mobile crane safety device according to the first example of the first embodiment of the present invention is attached, taking as an example the case where the mobile crane provided with the safety device is a crawler traveling type provided with a lattice-type boom. This will be described with reference to the drawings. FIG. 1 is a schematic side view of a mobile crane provided with a safety device according to a first example of Embodiment 1 of the present invention, and FIG. 2 is a mobile type according to the first example of Embodiment 1 of the present invention. It is a block diagram of the safety device of a crane. FIG. 3 is a graph showing the relationship between the actual load of the suspended load and the actual work radius, and FIG. 4 is a flowchart of the safety device for the mobile crane according to the first example of the first embodiment of the present invention. Figure 5 is a first relates to example, a graph showing the relationship of the working radius ratio α and forecasts broadcast load factor L _A by setting the state quantity L ₀ of suspension members of the first embodiment of the present invention, FIG. 6 relates to the first example of the first embodiment of the present invention, is a graph showing the relationship between the setting state of counterweight (wt) and working radius ratio α by C forecast broadcast load factor L _a.

The mobile crane provided with the safety device according to the first example of the first embodiment of the present invention includes a crawler traveling lower traveling body 1 as shown in FIG. This of On the lower traveling body 1, is mounted an upper rotating body 2 to be pivoted in a vertical turning center C _L around the front portion of the upper rotating body 2 through a boom foot pin 3 _P lattice A mold boom 3 is mounted so as to be raised and lowered, and a counterweight 2 a is disposed at the rear end of the upper swing body 2. One end side of the guy cable 5 is connected to the vicinity of the tip of the boom 3 and the other end side is connected to the upper spreader 6.

  Between the upper spreader 6 and a plurality of sheaves (not shown) between the upper spreader 6 and the lower spreader 7 connected to the top of the gantry 4 erected on the upper part of the rear portion of the upper swing body 2, the upper swing body 2 is provided. A boom hoisting rope 9 is wound around a boom hoisting drum 8 provided on the hoisting and unwinding. That is, the boom 3 of the mobile crane is configured to be raised and lowered by the upper and lower spreaders 6 and 7 whose gaps are expanded and contracted by winding and unwinding the boom hoisting rope 9 and the guy cable 5.

A guide sheave 3a and a top sheave 3b are provided at the tip of the boom 3, and a hoisting rope 10 is wound around the sheaves 3a and 3b by a hoisting drum 11 provided in the upper revolving body 2 and is rewound. It is being handed over. Then, the hoisting ropes 10, a plurality of sheaves of the top wheel 3b, together with the wrapped around the plurality of sheaves of hook block 12 with a hanging Jisuru hook 13 suspended load of actual load W _L, the hook block The leading end of the hoisting rope 10 that is turned upward by one of the twelve sheaves is connected to the lower position of the top sheave 3 b of the boom 3. That is, the hook 13 is configured to be moved up and down by winding and unwinding the winding rope 10. The distance R between the vertical line passing through the load center of the suspended load of the turning center C _L and the actual load W _L is the actual working radius.

  The mobile crane configured as described above is automatically stopped to prevent the mobile crane from overturning due to an overload during crane operation, and safety for notifying that the mobile crane is about to fall over. A device 20 is provided. The safety device 20 is provided on a control device 30 to be described later, a boom angle meter (boom angle detecting means) 21 for detecting the raising / lowering angle θ of the boom 3, and a boom raising / lowering rope 9 that raises and lowers the boom 3. A load meter (load detection means) 22 and a boom length meter (boom length detection means) 23 for detecting the tension of the boom and measuring the boom lifting force P are provided.

  Further, the safety device 20 is operated by a stop command signal output from the control device 30 to automatically stop the operation of the mobile crane, for example, the lowering operation of the boom 3 and the lifting operation of the hook 13. (Danger avoidance control means) 24 and a forecast notification means for operating a notification command signal output from the control device 30 based on the calculation result to notify a forecast that the mobile crane is approaching a danger state of falling. For example, a forecast buzzer, a forecast speaker, or a forecast lamp) 25 is provided.

  In addition, as a boom length meter, the following types are used, for example. That is, in a mechanical mobile crane equipped with a lattice boom, a boom length meter 23 for inputting the boom length is used. In a hall-type mobile crane equipped with a multistage telescopic boom, a boom length meter is used in which a wire is drawn out and retracted by expansion and contraction of the multistage telescopic boom. Further, as described above, the forecast notification means 25 functions to notify a forecast that the mobile crane is approaching a danger state where the mobile crane will fall down. However, the mobile crane reaches an overload state automatically. It also serves to make the operator recognize in advance that it will stop.

The control device 30 is inputted with a plurality of set state quantities of the mobile crane, that is, a set state quantity L _O of the suspension member and a set state quantity (weight) C of the counterweight, and the inputted set state of the mobile crane. The storage unit 31 for storing the quantity, the set state quantity data, the boom angle meter 21, the load meter 22, and the boom length meter 23 from the storage unit are input detection values. It is used to calculate various state quantities, perform comparison and determination, send a stop command signal to the automatic stop circuit 24, and send a forecast command signal to the forecast notification means 25 to operate. An arithmetic unit 32 is provided.

The calculation unit 32 of the control device 30 includes a plurality of calculation means as described below.
(1) Work radius calculation means 32a for calculating the actual work radius R based on the detection results of the boom length detector 23 and the boom angle meter 21.
(2) work rating for calculating the rated working radius R _S corresponding to the actual load W _L of the suspended load radius calculation means 32b
(3) First margin calculating means 32c for calculating the first margin of the actual working radius R with respect to the rated working radius R _S
(4) Forecast determination means 32d for determining whether or not it is in an overload forecast state based on the first margin.
(5) A rated state for calculating a rated state quantity relating to a predetermined state quantity obtained from a detection result of at least one of the detecting means, for example, calculating a corresponding rated load W from an actual work work radius Quantity calculating means 32e
(6) Second margin calculating means 32f for calculating a second margin (load factor L) of a predetermined state quantity with respect to the rated state quantity.
(7) Overload determination means 32g for determining whether or not an overload state is based on the second margin (load factor L).

In the mobile crane, as shown in FIG. 3, the load of a suspended load that can be suspended decreases as the actual work radius R increases. Here, a rated load for actual work radius is W, the actual load of the suspended load is assumed to be W _L, the load factor of the mobile crane when L (second allowance), L = W _L / W × 100 (%). Since the rated load W of the mobile crane decreases as the actual working radius R increases, the mobile crane gradually becomes in danger as the load factor L increases. Therefore, when the load factor L exceeds a certain value, a forecast is notified to allow the operator to recognize that the mobile crane is approaching a dangerous state, and when the load factor L reaches a predetermined rate, for example, 100%. A mobile crane is known that automatically stops based on the fact that the load factor L reaches 100%.

The present invention further improves the safety of the mobile crane based on the conventional technology as described above, and considers the influence of the actual work radius that changes depending on the crane posture even if the actual load of the suspended load is the same. Is. Incidentally, the rated case 3, the rated working radius when the actual load of the suspended load of the mobile crane is W _L is R _S, and the actual load of the suspended load is lighter W _{L 'from} W _L working radius is shown to be a _{R S} larger _{R S} '.

The operation of the mobile crane safety device 20 according to the first example of the first embodiment will be described below with reference to FIG. 4 of the flowchart. First, in step S ₁ , the set state amount L ₀ of the crane undercarriage member and the set state amount (weight) C of the counterweight are set as the plurality of set state amounts of the mobile crane in the storage unit 31 of the control device 30. At the same time, the boom raising / lowering angle θ, the boom raising / lowering force P, and the boom length L _B are inputted from the boom angle meter 21, the load meter 22, and the boom length meter 23 to the calculation unit 32 of the control device 30, and step S _2. Proceed to

The boom hoisting force P is obtained from the tension of the hoisting rope when the mobile crane is a rope hoisting type, and from the pressure of the hoisting cylinder when the mobile crane is a cylinder hoisting type. It is required. The setting state quantity L ₀ of the crane suspension member is a state quantity relating to the crane stability based on distance between the centers in the width direction of the left and right crawler when mobile cranes are cranes, and wheel In the case of a crane, this is a state quantity related to crane stability based on the distance between the load application points of the left and right outriggers.

In step S _2, the setting state quantity L ₀ set in step S _1, C, element status of each element θ, P, L _B and mobile load rating (rated state quantity calculating means 32e defined by crane posture of the crane From the rated state quantity (W) calculated in step S, the actual load W _{L of the} suspended load, the actual work radius R, the load factor L (second margin), and the rated work radius R _S for the actual load W _L of the suspended load are obtained. At the same time, the actual working radius R is divided by the rated working radius R _S to calculate a working radius ratio α (α = R / R _S : first margin), and the process proceeds to Step S ₃ .

In step S ₃ , a forecast determined from the relationship between the working radius ratio α and the crane underbody member setting state quantity L ₀ as shown in FIG. 5 that has been previously input and stored in the storage unit 31 of the control device 30. and calculates the notification to forecast broadcast load factor L _{a (forecast} tolerance of the second margin), the process proceeds to step S _4.

Incidentally, FIG. 5 may be the working radius ratio α are the same, when the setting state quantity L ₀ of the crane suspension member is large indicates that a large forecast broadcast load factor L _A is calculated, the reverse If the set state quantity L ₀ of the crane suspension member is small small forecast broadcast load factor L _a indicates that it is calculated. Mobile settings of the crane suspension member of the crane _{L 0 (e.g., L O MAX, L O MID} , L O MIN) by the data indicating the relationship between such work radius ratio α and forecasts broadcast load factor _{L A} is , Input in advance to the storage unit 31 of the control device 30. In the case of FIG. 5, a standard counterweight is attached to the rear end portion of the upper swing body of the mobile crane, and the set state amount (weight) C of the counterweight is not changed. Is the case.

In step S _{4 (overload} determination means 32 g), the load factor L (second margin) is a predetermined percentage, whether reaches for example 100% is determined. When the load factor L has reached 100% and it is determined that the vehicle is overloaded, a stop command signal is output to the automatic stop circuit 24, and the boom is controlled based on the stop command signal. The lowering operation and the hook winding operation are automatically stopped. On the other hand, when the load factor L has not reached 100% and it is determined that the load is not overloaded, a stop command signal for automatically stopping the mobile crane is not output to the automatic stop circuit 24. since, the process proceeds to step S ₅ in order to determine whether to output the forecast command signal that approaches a dangerous situation mobile crane to tip over.

In step S _{5 (prediction} judging means 32d), the load factor L which varies every moment depending continued crane work is determined whether or not reached forecast broadcast load factor L _A the ever changing. In the case of No where the load factor L is determined not to reach the forecast broadcast load factor L _A, the process returns to step S _1. In the case of Yes in which the load factor L is determined to have reached the forecast broadcast load factor L _A is forecast command signal to the forecast informing means for informing a prediction is output, the flow returns to step S _1.

  When a forecast command signal is output to the forecast notifying means, and when the forecast is notified from the forecast notifying means, the operator can detect the change in the load factor L from when the forecast is noticed until the mobile crane automatically stops. The actual working radius at which the mobile crane automatically stops can be easily predicted.

According to the mobile crane safety device 20 according to the first example of the first embodiment, the load factor L of the mobile crane calculated by the control device 30 of the safety device 20 is the actual load W of the suspended load. based on reaching the forecast broadcast load factor L _a calculated in accordance with the working radius ratio α is the ratio of the rated working radius R _S with respect to the actual operating radius R and the actual load W _L in _L, forecast notification means forecasts of load factor L has reached the forecast broadcast load factor L _a from is notified.

Even if the crane posture and boom length are different due to the notification of the forecast, the operator will perform the actual work in which the mobile crane automatically stops due to the change in the load factor L from when the forecast is reported until the mobile crane automatically stops. _A predetermined amount (100% −L _A ) of the change amount of the radius can be easily predicted. Therefore, the operator can stop the operation of the mobile crane with a margin. Therefore, the automatic stop of the mobile crane is avoided and the swinging of the mobile crane due to the sudden stop of the mobile crane can be prevented, so that the excellent effect that it can greatly contribute to the improvement of safety in the crane work. Obtainable.

By the way, the set state amount L ₀ of the crane underbody member (when the mobile crane is a crawler crane, it is a state amount related to the crane stability based on the distance between the centers in the width direction of the left and right crawlers. Is the state quantity related to the crane stability based on the distance between the load application points of the left and right outriggers), and when the rated load changes due to a change in the set state quantity (weight) C of the counterweight Is a forecast notification load factor L _A for reporting a forecast from the relationship between the working radius ratio α and the counter weight setting state quantity (weight) C (for example, C _MAX , C _MID , C _MIN ) as shown in FIG. The required data is input to the storage unit 31 of the control device 30 in advance.

Then, by setting a counterweight setting state quantity (weight) C in the storage unit 23a of the control device 30, it is possible to cope with a change in the rated load due to the counterweight. Further, when the rated load changes due to a change in the counterweight setting state quantity (weight) C, it is determined from the relationship between the working radius ratio α and the crane underbody member setting state quantity L ₀ as shown in FIG. You should enter the data for obtaining the forecast broadcast load factor L _a in advance in the storage unit 31 of the control device 30. Then, it is possible to use the forecasts broadcast load factor L _A to thereby obtained is computed, corresponding to changes in the rated load by the counter set state of weights (weight) C.

In the case of a mobile crane having an outrigger, such as a wheel crane, the distance between the load application points of the left and right outriggers cannot always be set to the maximum. Depending on the work site, the load application point of the left and right outriggers The spacing between them may be different. In such a case, the rated load changes depending on the turning operation. Therefore, the turning angle of the upper turning body is further input as data to the calculation unit 32 of the control device 30 to cope with the same. . In addition, the boom hoisting speed, telescopic speed (wheel crane), the turning speed of the upper turning body, the load swing, and the height of the suspended load are input, and the forecast notification load factor is determined according to the size of each input data. L _a and by changing the relationship between the working radius ratio alpha, it is also possible to configure to notify the forecast safer side.

A mobile crane safety device according to a second example of Embodiment 1 of the present invention will be described with reference to the attached drawings. Figure 7 is a flow chart of the safety device of the mobile crane according to the second example of the first embodiment of the present invention, FIG 8 is forecast broadcast work with actual load W _L of the suspended load by the setting state quantity L ₀ of the crane suspension member graph showing the relationship between the radius ratio alpha _a, Figure 9 is a crane foot setting state of counterweight each setting state quantity L ₀ of about member (weight) the actual load W _L and forecast notification working radius ratio of the suspended load by C It is a graph which shows the relationship of (alpha) _A.

In step S ₁ , a set state quantity L ₀ of the crane undercarriage member and a set state quantity (weight) C of the counterweight are set as a plurality of set state quantities of the mobile crane in the storage unit 31 of the control device 30. At the same time, an element state quantity signal of each element from the boom angle meter 21, load meter 22, and boom length gauge 23, that is, the boom lifting angle θ, which is the element state quantity, the boom lifting force P, entered boom length L _B is the flow proceeds to step S _2.

In step S _2, the setting state quantity L ₀ set in step S _1, C, element status of each element theta, P, L _B and the rated load W which is determined by the crane position of mobile crane, the suspended load real load _{W L,} the actual operating radius R, the load factor L (second margin), and calculates the rated working radius _{R S} with respect to the actual load _{W L} of the suspended load. Further, the actual working radius R is divided by the rated working radius R _S to calculate a working radius ratio α (first margin), and the process proceeds to Step S ₃ .

In step S _3, the control device 30 stored in advance to notify forecast from the relationship between the setting state quantity L ₀ of the actual load W _L and crane undercarriage member of the suspended load as shown in FIG. 8 had been, first the process proceeds to step S ₄ is a forecast tolerance margin forecast broadcast working radius ratio alpha _{a (the} forecast allowable working radius ratio) was calculated. Incidentally, FIG. 8, actual load W _L of the suspended load is calculated large forecast broadcast working radius ratio alpha _A is larger setting state quantity L ₀ of the crane suspension member be the same, the crane suspension conversely If the set state quantity L _{0 of the} member is small, it indicates that a small forecast notification work radius ratio α _A is calculated. Moreover, the setting state of the crane suspension member _{L 0 (e.g., L O MAX, L O MID} , L O MIN) by, forecast notification working radius ratio for notifying the forecast and actual load _{W L} of such a suspended load α Data indicating the relationship of _A is input to the storage unit 31 of the control device 30 in advance.

In step S ₄ (overload determination means 32g), it is determined whether or not the load factor L has reached a predetermined ratio, for example, 100%. When the load factor L has reached 100% and it is determined that the vehicle is overloaded, a stop command signal is output to the automatic stop circuit 24, and the boom is controlled based on the stop command signal. The lowering operation and the hook winding operation are automatically stopped. On the other hand, if the load factor L has not reached 100% and it is determined that the load is not overloaded, a stop command signal for automatically stopping the mobile crane is not output to the automatic stop circuit 24. since, the process proceeds to step S ₅ in order to determine whether to output the forecast command signal that approaches a dangerous situation mobile crane to tip over.

In step S ₅ (forecast determination means 32d), it is determined whether or not the work radius ratio α has reached the forecast notification work radius ratio α _A for reporting the forecast. In the case of No of working radius ratio alpha is determined not to reach the forecast notification working radius ratio alpha _A returns to step S _1. In the case of Yes the working radius ratio alpha is determined to have reached the forecast notification working radius ratio alpha _A is forecast notification command signal is output to the prediction notification means, the flow returns to step S _1.

  When the forecast is notified from the forecast notification means based on the output of the forecast command signal, the operator automatically stops the mobile crane from the change in the work radius ratio α after the forecast is notified until the mobile crane automatically stops. The predetermined amount of change in the actual work radius can be easily predicted.

According to the mobile safety device for a crane 20 according to the second example of the first embodiment, the actual operating radius R at the actual load W _L of the suspended load of the mobile crane found by calculation by the control unit 30 thereof working radius ratio is the ratio of the rated working radius R _S with respect to the actual load W _L of the suspended load alpha is, based on reaching the actual load W forecast broadcast work was calculated according to the _L radius ratio alpha _a of the suspended load Thus, a forecast that the work radius ratio α has reached the forecast notification work radius ratio α _A is notified from the forecast notification means.

Therefore, even if the crane posture and the boom length are different, the operator can perform the actual work in which the mobile crane automatically stops due to the change in the work radius ratio α from when the forecast is notified until the mobile crane automatically stops. _A predetermined amount (1-α _A ) of the amount of change in radius can be easily predicted. Therefore, the operator can stop the operation of the mobile crane with a margin, the automatic stop of the mobile crane can be avoided, and the load can be prevented from being shaken due to the sudden stop of the mobile crane. The effect that it can contribute greatly with respect to improvement of can be acquired.

Even when the setting state of the counterweight in addition to setting the state quantity L ₀ of the crane suspension member (weight) load rating due to a change in C changes can be accommodated.

That is, as shown in FIG. 9, the actual load W _L of the suspended load and the set state amount (weight) C of the counterweight for each set state amount L ₀ of the crane suspension member (for example, C _MAX , C _MID , C _MIN The data for obtaining the forecast notification work radius ratio α _A from the relationship with the above) may be input to the storage unit 31 of the control device 30 in advance, and the forecast notification work radius ratio α _A obtained from this may be used. The setting state of counterweight (weight) of each C, and actual load W _L and forecasts broadcast working radius ratio from the relation between the setting state quantity L ₀ of the crane suspension member alpha _A of the suspended load as shown in FIG. 8 have entered the storage unit 31 in advance controller 30 the data to determine, it may be used forecasts notification working radius ratio alpha _a obtained therefrom.

A mobile crane safety device according to a third example of the first embodiment of the present invention will be described with reference to FIG. 10 of the flowchart of the mobile crane safety device. In addition, since the mobile crane provided with the safety device according to the third example of the first embodiment of the present invention has the same configuration as the mobile crane provided with the safety device according to the first example of the first embodiment. The description related to the configuration of the mobile crane is omitted, and only the description related to the safety device is given.

In step S ₁ , a set state amount L ₀ of the crane undercarriage member and a set state amount (weight) C of the counterweight are set as a plurality of set state amounts of the mobile crane in the storage unit 31 of the control device 30. The control unit 30 includes an operation state 32, a boom angle meter 21, a load meter 22, and a boom length meter 23. Element state quantity signals of each element, that is, an element state quantity boom undulation angle θ, boom undulation force P, boom is input the length _{L B,} the processing proceeds to step _{S 2.}

In step S _2, the setting state quantity L ₀ set in step S _1, C, element status of each element theta, P, L _B and the rated load W which is determined by the crane position of mobile crane, the suspended load real the process proceeds to step _{S 3} calculates a load _{W L,} the actual operating radius R, the load factor L (second margin), and the rated working radius _{R S} with respect to the actual load _{W L} of the suspended load.

In step S ₃ , a work radius difference R _A (first margin) that is a difference (R _S −R) between the rated work radius R _S and the actual work radius R is calculated, and the process proceeds to step S ₄ .

In step S ₄ (overload determination means 32g), it is determined whether or not the load factor L has reached a predetermined ratio, for example, 100%. When the load factor L has reached 100% and it is determined that the vehicle is overloaded, a stop command signal is output to the automatic stop circuit 24, and the boom is controlled based on the stop command signal. The lowering operation and the hook winding operation are automatically stopped. On the other hand, when the load factor L has not reached 100% and it is determined that the load is not overloaded, a stop command signal for automatically stopping the mobile crane is not output to the automatic stop circuit 24. since, the process proceeds to step S ₅ in order to determine whether to output the forecast command signal that approaches a dangerous situation mobile crane to tip over.

In step S ₅ (forecast determination means 32d), it is determined whether or not the work radius difference _RA has reached a preset forecast notification work radius margin value r (predicted work radius difference forecast value).
In the case of No that the industry radius difference R _A is determined not to reach the forecast notification working radius margin value r, the process returns to step S _1. On the other hand, in the case of Yes in which the working radius difference R _A is determined to have reached the forecast notification working radius margin value r is forecast command signal is output to the prediction notification means, the flow returns to step S _1.

According to the mobile crane safety device 20 according to the third example of the first embodiment, the difference is between the rated work radius _RS and the actual work radius R calculated by the control device 30 of the safety device 20. Based on whether or not the work radius difference _RA has reached a preset forecast notification work radius margin value r (forecast allowable value of work radius difference), it is determined whether or not an overload prediction state is present. . In the overload forecast state, the forecast is notified from the forecast reporting means, but the amount of change in the actual work radius from when the forecast is reported until the automatic stop by the automatic stop circuit of the mobile crane is executed. The fixed amount (forecast notification work radius margin value r) is known. Therefore, the operator can stop the operation of the mobile crane with a margin, and the risk avoidance control by the automatic stop of the mobile crane, for example, the automatic stop is avoided, and the swinging of the mobile crane due to the sudden stop can be prevented. Therefore, it is possible to obtain an excellent effect that it can greatly contribute to the improvement of safety in crane work.

  A mobile crane safety device according to Embodiment 2 of the present invention will be described with reference to FIG. 11 of the flowchart of the mobile crane safety device. In addition, since the mobile crane provided with the safety device according to the second embodiment of the present invention has the same configuration as the mobile crane provided with the safety device according to the first example of the first embodiment, The description related to the configuration is omitted, and only the description related to the safety device.

In step S _1, a plurality of setting states of the mobile crane in the storage unit 31 of the control unit 30, setting the state quantity L ₀ of the crane undercarriage _member, and setting the state of counterweight (wt) C is set At the same time, an element state quantity signal of each element from the boom angle meter 21, load meter 22, and boom length gauge 23, that is, the boom undulation angle θ, which is the element state quantity, and the boom undulation force P , it is entered boom length _{L B} proceeds to step _{S 2.}

In step S _2, a plurality of settings quantity L ₀ set in step S _1, C, element status of each element theta, P, from the rated load W which is determined by the crane posture of L _B and a mobile crane, the suspended load actual load W _L of _the actual operating radius R, the load factor L (second margin), and thereby calculates the rated working radius R _S with respect to the actual load W _L of the suspended load, the rated working the actual operating radius R The work radius ratio α (first margin) is calculated by dividing by the radius R _S and the process proceeds to step S ₃ .

In step S _3, forecast broadcast load factor L for notifying forecast determined from the relationship between the setting state quantity L ₀ of working radius ratio α and the crane chassis member, as shown in FIG. 5 which has been previously allowed stored in the control unit 30 _A (the forecast allowance of the second margin) is calculated. Further, the forecast notification working radius ratio alpha _{A (working} radius ratio for informing the forecast from the relationship between the actual load W _L and the overhang width L ₀ of the suspended load as shown in FIG. 8 stored in advance in the controller 30 Calculate forecast tolerance). Further, a work radius difference R _A (first margin) that is a difference between the rated work radius R _S and the actual work radius R is calculated, and the process proceeds to step S ₄ .

In step S ₄ (overload determination means 32g), it is determined whether or not the load factor L has reached a predetermined ratio, for example, 100%. If the load factor L has reached 100% and it is determined that the vehicle is overloaded, a stop command signal is output to the automatic stop circuit, and the boom winding is performed based on the stop command signal. The lowering operation and the hook winding operation are automatically stopped. On the other hand, if the load factor L has not reached 100% and it is determined that the load is not overloaded, a stop command signal for automatically stopping the mobile crane is not output to the automatic stop circuit 24. since, the process proceeds to step S ₅ in order to determine whether to output the forecast command signal that approaches a dangerous situation mobile crane to tip over.

In step S _{5 (prediction} judging means 32d), whether the load ratio L has reached the forecast broadcast load factor L _A of notifying the forecast, forecast notification working radius ratio the working radius ratio α is to notify the forecast α whether reached _a, and whether the operating radius difference R _a has reached a predetermined forecast broadcast working radius margin value r it is determined in parallel. Wherein the load factor L is forecast broadcast load factor L _A, the working radius ratio alpha is forecast notifying working radius ratio alpha _A, also the working radius difference R _A has not reached the preset forecast broadcast working radius margin value r in the case of with and without the determined no, the flow returns to step S _1.

Meanwhile, whether the load ratio L reaches the forecast broadcast load factor L _A, the working radius ratio or alpha reaches forecast notification working radius ratio alpha _A, the working radius difference forecasts broadcast operating radius afford R _A is set in advance When the value r is reached, that is, the forecast allowable value corresponding to any one of the load factor L, the work radius ratio α, and the work radius difference _RA (the forecast notification load factor L _A , the forecast notification work radius ratio). If it is determined that α _A has reached the forecast notification work radius margin value r), a forecast notification command signal is output to the forecast notification means, and the process returns to step S ₁ .

According to the mobile crane safety device 20 according to the second embodiment of the present invention, the load factor L of the mobile crane calculated by the control device 30 of the safety device 20 is the actual load W of the suspended load first. when it reaches the rated working radius R _S is the ratio of the working radius ratio α forecast broadcast load factor L _a, which is calculated according to the relative actual load W _L of the actual operating radius R and its suspended load in the _L, the based on this, the load factor L from forecast informing means forecasts that reaches the forecast broadcast load factor L _a is notified.

The ratio of the actual work with the actual load W _L of the suspended load of the mobile crane radius R and the rated working radius R _S with respect to the actual load W _L of the suspended load obtained by calculating by the control unit 30 of the safety device 20 working radius ratio alpha is, when it reaches the calculated forecast broadcast working radius ratio alpha _a according to the actual load W _L of the initially suspended load, on the basis of this, the working radius ratio from forecast information means _A forecast that α has reached the forecast reporting work radius ratio α _A is reported.

When the work radius difference _RA between the rated work radius R _S and the actual work radius R calculated by the control device 30 of the safety device 20 reaches a preset forecast notification work radius margin value r. _A forecast that the working radius difference _RA or the forecast reporting work radius margin value r has been reached is reported.

According to the safety device for a mobile crane according to the second embodiment of the present invention, even when the crane posture and the boom length are different, the load factor L until the mobile crane automatically stops after the forecast is notified. From any one of the change, the change in the work radius ratio α, or the change in the work radius difference _RA , the operator can easily predict the actual work radius at which the mobile crane automatically stops. Therefore, the operator can stop the operation of the mobile crane with a margin, the automatic stop of the mobile crane can be avoided, and the load can be prevented from being shaken due to the sudden stop of the mobile crane. It is possible to obtain an excellent effect that it can greatly contribute to the improvement of.

In addition, according to the mobile crane safety device according to the second embodiment of the present invention, the forecast allowance for notifying three forecasts, that is, the load factor L _A , the forecast reporting work radius ratio α _A , and the forecast reporting work radius margin value r. The forecast is notified based on the forecast allowable value that is first reached among the forecast allowable values that have values and notify the forecast. Therefore, since the forecast is notified on the safety side of any of the mobile crane safety devices according to the first to third embodiments of the first embodiment, the safety of the crane operation of the mobile crane is excellent. Yes.

For safety apparatus for a mobile crane according to the second embodiment of the present invention, when the load factor L has reached the first forecast broadcast load factor L _A is based on forecasts broadcast load factor L _A, working radius ratio alpha is in when it reaches the first forecast notification working radius ratio alpha _A based on forecasts notification working radius ratio alpha _A, also when the working radius difference R _A has reached the initially forecast notification working radius margin value r is The system is configured to notify a forecast based on the forecast notification work radius margin value r, that is, has a forecast allowable value for reporting three forecasts. However, the present invention is not limited to such a configuration. For example, a configuration having two forecast allowable values of the forecast notification load factor L _A and the forecast notification work radius ratio α _A , the forecast notification load factor L _A and the forecast notification work radius margin value. A configuration having two forecast allowable values of r, a configuration having two forecast allowable values of a forecast notification work radius ratio α _A and a forecast notification work radius margin value r can be adopted.

FIG. 1 is a schematic side view of a mobile crane provided with a safety device according to a first example of Embodiment 1 of the present invention. It is a block diagram of the safety device of the mobile crane which concerns on the 1st example of Embodiment 1 of this invention. It is a graph which shows the relationship between the actual load of a suspended load, and an actual work radius. It is a flowchart of the safety device of the mobile crane which concerns on the 1st example of Embodiment 1 of this invention. Relates to the first example of the first embodiment of the present invention, is a graph showing the relationship between operating radius ratio α and forecasts broadcast load factor L _A by setting the state quantity L ₀ of suspension members. Relates to the first example of the first embodiment of the present invention, is a graph showing the relationship between the setting state of counterweight (wt) and working radius ratio α by C forecast broadcast load factor L _A. It is a flowchart of the safety device of the mobile crane which concerns on the 2nd example of Embodiment 1 of this invention. Figure 8 is a graph showing the relationship between the actual load W _L and forecast notification working radius ratio alpha _A of the suspended load by the setting state quantity L ₀ of the crane suspension member. It relates to the second example of the first embodiment of the present invention, the setting state of counterweight each setting state quantity L ₀ of the crane suspension member (weight) the actual load W _L and forecast notification working radius ratio of the suspended load by C It is a graph which shows the relationship of (alpha) _A. It is a flowchart of the safety device of the mobile crane which concerns on the 3rd example of Embodiment 1 of this invention. It is a flowchart of the safety device of the mobile crane which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lower traveling body, 2 ... Upper turning body, 2a ... Counterweight, 3 ... Boom, 3a ... Guide sheave, 3b ... Top sheave, _3P ... Boom foot pin, 4 ... Gantry, 5 ... Guy cable, 6 ... Upper Spreader, 7 ... Lower spreader, 8 ... Boom hoisting drum, 9 ... Boom hoisting rope, 10 ... Hoisting rope, 11 ... Hoisting drum, 12 ... Hook block, 13 ... Hook 20 ... Safety device, 21 ... Boom angle meter, 22 ... Load meter, 23 ... boom length meter, 24 ... automatic stop circuit (danger avoidance control means), 25 ... forecast notification means,
DESCRIPTION OF SYMBOLS 30 ... Control apparatus, 31 ... Memory | storage part, 32 ... Calculation part, 32a ... Work radius calculation means, 32b ... Rated work radius calculation means, 32c ... First margin calculation means, 32d ... Forecast determination means, 32e ... Rated state Quantity calculating means, 32f ... second margin calculating means, 32g ... overload determining means C ... counterweight set state quantity (weight), C _L ... turning center (upper turning body)
L ... load factor (the second margin), L A _... forecast broadcast load factor (forecast tolerance of the second margin), L B _... boom length, L 0 _... setting state quantity P of the crane suspension member Boom hoisting force R ... Actual working radius, R _A ... Working radius difference (first margin), R _S ... Rated working radius, r ... Forecast notification working radius margin (predictable value of working radius difference)
W ... Rated load, W _L ... Actual load of suspended load α ... Work radius ratio (first margin), α _A ... Forecast notification work radius ratio (forecast allowable value of work radius ratio)
θ ... Boom undulation angle

Claims (5)

  At least 3 including load detection means for determining the actual load of the suspended load suspended from the tip of the boom, boom length detection means for detecting the boom length, and boom angle detection means for detecting the boom undulation angle More than types of detection means, work radius calculation means for calculating an actual work radius based on the detection results of the boom length detection means and the boom angle detection means, and a rated work radius corresponding to the actual load of the suspended load A rated working radius calculating means, a first margin calculating means for calculating a first margin of the actual working radius with respect to the rated working radius, and whether or not an overload forecast state is based on the first margin A forecast determination unit for determining whether the forecast determination unit is in an overload forecast state, a forecast notification unit for reporting a forecast that danger avoidance control is performed, and a small number of the detection units. Rated state quantity calculating means for calculating a rated state quantity related to a predetermined state quantity obtained from the detection result of at least one detecting means, and a second state for calculating a second margin of the predetermined state quantity with respect to the rated state quantity. It is dangerous when it is determined that the overload determination means, the overload determination means for determining whether or not an overload condition is based on the second allowance, and the overload determination means is in an overload condition A risk avoidance control means for performing avoidance control, and a change amount of an actual work radius from notification of the forecast by the forecast notification means to execution of the risk avoidance control by the risk avoidance control means is a predetermined amount. A mobile crane safety device characterized by that.   The first margin is a work radius ratio, which is a ratio of an actual work radius to a rated work radius, and the forecast determination means is configured so that the second margin is preset according to the work radius ratio. 2. The mobile crane safety device according to claim 1, wherein it is determined whether or not an overload prediction state is reached based on whether or not a margin allowance forecast value of 2 has been reached.   The first margin is a work radius ratio that is a ratio of an actual work radius to a rated work radius, and the forecast determination means has a work radius in which the work radius ratio is preset according to the predetermined state quantity. The safety device for a mobile crane according to claim 1, wherein it is determined whether or not an overload prediction state is reached based on whether or not a forecast allowable value of the ratio has been reached.   The first margin is a work radius difference that is a difference between a rated work radius and an actual work radius, and the forecast setting means has the work radius difference reaching a preset work radius difference forecast allowable value. The mobile crane safety device according to claim 1, wherein it is determined whether or not an overload prediction state is established based on whether or not the vehicle is overloaded.   The forecast determination means includes a second tolerance allowance preset in accordance with a work radius ratio that is a ratio of an actual work radius to a rated work radius, and a work radius preset in accordance with a predetermined state quantity. Predicted tolerance value of the ratio, which has a forecast tolerance value of a work radius difference which is set in advance and is a difference between the rated work radius and the actual work radius, the second margin corresponding to these three forecast tolerance values, the work radius Of the three first margins, i.e., the ratio and the work radius difference, it is determined whether or not the vehicle is in an overload forecast state based on the first margin that first reaches the corresponding forecast allowable value. The safety device for a mobile crane according to claim 1.

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