JP2000136090A - Sink judge device of working car provided with outrigger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge the danger of the sink and fall down of a working car generated in working by always comparing the data obtained in working with the allowable support force or the numerical index showing the dangerous sink. SOLUTION: A sink characteristic is decided by the relation between a grounding pressure (p) and a sink amount (y). A sink judge device is composed of a mechanism for finding out the grounding pressure (p), a mechanism for finding out the sink amount (y) and a controller. The controller finds out an inputted reaction force Fi, a sink amount (yi) and dp/dy from the data of the area A of a float or spread plate and the allowable support force is estimated and calculated. Thereafter, the grounding pressure (p) or dp/dy is found out from these inputted values and whether this value is the grounding pressure approaching to the allowable support force or not or the value approaching to dp/dy near the allowable support force or not is watched and when the dangerous area is judged, the operation order of warning or the stop to the related work machine is ordered and the danger of the sink is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial vehicle or a construction machine provided with an outrigger for ensuring the stability or levelness of a lower portion during work (hereinafter, an industrial vehicle and a construction machine are collectively referred to as a work vehicle). The present invention relates to a device for determining early when dangerous descent is likely to occur together with an outrigger installed during operation of a work vehicle.

[0002]

2. Description of the Related Art A work vehicle equipped with an outrigger, for example, a mobile crane that performs work by hanging a load at the tip of a boom, and raising and lowering and turning the boom has a risk of sinking and falling of the work vehicle. I have. So in these work vehicles,
First, use the outrigger to obtain a stable lower structure during work, and then calculate the allowable moment of the boom that does not fall with the outrigger as a fulcrum based on the working posture, in order to further prevent the danger of falling due to load movement etc. If the moment exceeds the allowable moment due to extension or load, a fall prevention device such as stopping the movement of the boom or issuing an alarm is prepared.

[0003] In the above-mentioned overturn prevention device, the outrigger of the work vehicle is normally operated under the premise that the outrigger is installed on relatively stable horizontal solid ground, so that the float of the outrigger is large. In the case of sinking, the fall prevention device does not operate properly, and there is a possibility that the vehicle body may fall. In fact, according to a report compiled by the Institute of Industrial Safety of the Ministry of Labor, when a mobile crane fell, settlement of the outrigger float was confirmed in about 41% of the total.

[0004]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 8-81181
In the publication, in order to cope with such a situation, in the configuration provided with each detecting means of the turning angle, the undulation angle, the boom length, the boom action load, and the outrigger overhang length,
First, the calculated supporting force acting on each outrigger when the ground contact does not subside by the detection means and the detected supporting force actually acting on the outrigger are obtained, and the relationship between the calculated supporting force and the detected supporting force is determined. At
Focusing on the difference in bearing capacity when the ground subsides, a system that issues an alarm in that case is proposed. However, in this technique, there is no means for calculating the jack amount of the outrigger, and it is necessary to arrange many sensors such as a sensor for detecting a turning angle, a boom length, etc., in order to obtain a supporting force in the case of no sinking. There was a problem in some points. An object of the present invention is to solve the problems of the conventional example as described above.

[0005]

In the present invention, attention is paid to the fact that the sinking and overturning of the work vehicle as described above occurs when the ground pressure due to the reaction force of the outrigger exceeds the allowable supporting force of the ground, The numerical value indicating the allowable bearing capacity of the ground or a dangerous subsidence is obtained from data obtained from time to time during the normal operation of the work vehicle, and thereafter, the data obtained during the same normal operation and the allowable support capacity or the dangerous By constantly comparing numerical indices representing the subsidence, when the outrigger's reaction force approaches the allowable bearing capacity of the ground, it is determined that it is dangerous, and an alarm is issued or the operation of the work machine is restricted.

[0006]

[Basic principle on which the present invention is based] The present invention as described above basically utilizes the following properties of the ground. As shown in FIG. 1, it is generally known that when the contact pressure p is gradually increased on a uniform ground, the amount of land sinking y accompanying the contact pressure draws a sinking characteristic curve as shown. . Here, the contact pressure shown by the vertical dotted line is the allowable bearing capacity of the ground, and if this allowable bearing capacity becomes a known value by some means, if the ground pressure p or dp / dy is monitored, the sinking Since the degree of progress is determined, it will be understood that it is only necessary to prevent a situation in which the pressure or dp / dy increases further when the allowable supporting force or the like is reached. The present invention is characterized in that the index indicating the marginal capacity of the ground such as the permissible supporting force is obtained from the relationship between the contact pressure p and the amount of settlement y in actual work. This point will be described in detail with reference to FIG. 1. On soft ground, it is desirable to obtain the relationship between the contact pressure and the settlement amount until the allowable bearing force qmax is obtained, but on a normal ground, the ground reaction force coefficient shown in FIG. K
As shown in the figure, the allowable bearing capacity can be estimated empirically if a linear slope is obtained from the relationship between the pressure and the amount of settlement at some points in a certain area. It is empirically known that if the ground constant E is obtained from the slope which is the relationship with the pressure at the point where the amount of 1.25 mm occurs, the allowable bearing capacity can be obtained at this stage. It takes advantage of its unique characteristics.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is characterized in that the permissible supporting force of the ground is determined during a normal operation of a work vehicle, that is, during a real-time operation. As described above, since the settlement characteristics of the ground are determined by the contact pressure p and the settlement amount y, the apparatus for implementing the present invention basically includes a means for determining the contact pressure p, the settlement amount y And a controller, which will be described below.

[0008] 1. Means for Determining Contact Pressure p To determine the contact pressure p, first, a contact reaction force F applied to the outrigger is determined by a sensor. FIGS. 2 and 3 show a means for obtaining the ground reaction force F when the H-type outrigger is used. That is, in FIG. 2, the pressures on the bottom side and the head side of the jack cylinder are obtained. The pressure on the bottom side is P _B , the bottom area A _B , the pressure on the head side is P _H , and the area on the head side is A _H. When a ground reaction force F is calculated by _{P B × a B -P H ×} a H, in FIG. 3, calculated on the ground plane of the outrigger load arranged load sensors, i.e. the ground reaction force F In each case, each detection value F detected at a fixed time interval
i is input to the controller after being subjected to processing such as amplification if necessary. On the other hand, in the controller, for example, by manual switch setting, or by automatic detection means or by taking in work data, planar data on floats and floor boards of outriggers, that is, data A on area and data α on shape α
Is entered. The data α relating to this shape is used, for example, to correct the shape effect based on those shapes in the case of flooring plates of various shapes with the case of outrigger float as a standard (in case of outrigger float, α is 1). The ratio was previously determined by a test as a ratio to the case of the outrigger float. Here, the controller calculates the contact pressure every time according to Pi = Fi / (A × α).

[0009] 2. Means for determining the amount of settlement y For detecting the amount of settlement, means for directly measuring the amount of settlement of the settlement below the subsidence, or vice versa In particular, as shown in FIG. 4, an inclination angle sensor is provided on the outrigger, and a method of calculating the settlement amount y by L × dθ from the sensor and the information L on the float position is particularly limited. Not done. Regardless of the detection means, the settlement amount y is detected as yi at certain time intervals, and after being subjected to processing such as amplification if necessary, is input to the controller. In the case of a vehicle having a plurality of outriggers, the means for determining the amount of settlement y and the means for determining the contact pressure p may be equipped with these detectors in all of them and function independently and simultaneously. Alternatively, the outrigger may be provided and function for the corresponding outrigger in the turning angle direction in which the sinking is concerned.

[0010] 3. Controller In the present invention, the controller basically has the following two roles as shown in FIG. One is dp based on the reaction force Fi and the amount of settlement yi input at regular time intervals and the data of the area A of the float or the floor plate.
/ Dy is determined, and the allowable bearing force or, for example, dp / dy at a position close to the allowable bearing force is estimated and calculated. This will be described with reference to FIG. 10 as an example. In the controller, the bottom pressure P _B of the outrigger cylinder and the bottom pressure P _B of the outrigger cylinder are used as ground reaction force calculation data for obtaining the ground pressure of the outrigger float or the floor plate constituting the ground member.
While the head-side pressure P _H are respectively input from the pressure sensor, the data relating to the area and shape of the ground member is input or automatically by manual operation as the area data for similarly obtaining the ground pressure, the controller of The ground pressure p is obtained from the data, and this ground pressure p
And dp / dy is obtained from the settlement amount y which is also data input to the controller. The other is to determine the contact pressure p or dp / dy from the above value which is also input at regular time intervals thereafter, and determine whether or not this value is the contact pressure approaching the allowable bearing force, or whether the allowable bearing force is obtained. D close to
The function is to monitor whether the value approaches p / dy or not, and when it is determined that the area is dangerous, it is an operation command to an alarm device, or a command to stop or reverse movement to a related work machine. Hereinafter, these roles of the controller will be described in more detail.

A. Calculation of allowable bearing capacity or dp / dy of danger stage by controller i. When the contact pressure increases in time series As shown in FIG. 6, when the contact pressure p increases in time series, the slopes (dotted lines) of several consecutive points are calculated by a straight-line square approximation method of these several points. And so on. From the determined dp / dy, the allowable bearing capacity or the allowable bearing capacity is obtained from the relationship between the inclination and the allowable bearing capacity on a uniform ground or from a comparison with a table obtained in a typical soil in advance and stored in a memory. The dp / dy leading to the force is determined, and this numerical value is a reference value for judging danger.

Ii. In the case where the contact pressure fluctuates in time series Unlike the case i, in an actual work vehicle, the reaction force applied to the outrigger float or the like, that is, the contact pressure is determined by the undulation, expansion and contraction, turning, It is a repetition of increasing and decreasing due to the operation of raising and lowering the ground. On the other hand, the amount of settlement has some amount of elastic deformation in addition to some plastic deformation due to the characteristics of the ground. Due to the change in the pressure, the contact pressure p and the amount of settlement y actually take the form shown in FIG. Therefore, even if the inclination is calculated from several points that are continuous in time series, the inclination and the characteristics of the subsidence of the ground will not be appropriately reflected.

In the present invention, the following processing is performed in order to obtain an appropriate relationship between the amount of subsidence y and the contact pressure p from the form of measured values in actual work as shown in FIG. As shown by the horizontal line in FIG. 8, the subsidence amount range is divided into sections, and among the input values of (pi, yi) belonging to each range, for example, the largest p
Will be remembered. In FIG. 8, each black dot indicates these representative values for each yi. The yi at this time may be yi when pi = pmaxj, or may be a representative value such as the median of the range j. Also, the ground reaction force (that is, the ground pressure p) does not need to be the maximum within the above range, and a value such as 80% of the maximum value is set in consideration of the electrical noise of the ground reaction signal. By adopting it, it is possible to obtain more allowable supporting force on the safe side. As described above, even in the actual work of the work vehicle in which the contact pressure fluctuates in time series, the d
Since p / dy is determined, similarly, the contact pressure p or the sinking amount y
From the relationship, the nature of the ground, that is, the sinking amount curve of the ground is estimated. As a result, the allowable supporting force or dp / dy that reaches the allowable supporting force can be obtained.

B. An operation command of an alarm device or the like by a controller Based on the allowable bearing capacity of the ground obtained as described above or dp / dy which can be regarded as a danger area, by constantly monitoring the ground pressure pi or dp / dy during work, If it is determined that the vehicle is approaching a dangerous ground pressure area or dp / dy, it issues an operation command to an alarm device (including a forecast device), issues a command to stop the operation of the work machine, or operates the work machine. Or a command that combines them.

An example of the operation of the apparatus for judging dangerous subsidence according to the present invention described above with reference to the main components will be described with reference to FIG. Note that FIG. 9 is only an example of one determination flow, and the order of input and calculation can be changed within the common sense of the parties.

When the apparatus starts, first, the operator inputs the area A of the grounding member below the outrigger or the shape of the grounding member (correction coefficient relating to the grounding member) by manual input, or includes a detection device. These are automatically inputted in the working machine. Then, the contact pressure F and the settlement amount y
Is started, the contact pressure p is calculated (converted) from the previously input area A of the contact member below the outrigger. As described above, the contact pressure calculated in this manner is not usually in a fixed relationship with the squat amount due to the repetition of the operation of the work equipment and the like. By determining a set of the representative value Pi (for example, Pmaxj which is the maximum value) and yi, a partial characteristic curve of the contact pressure P and the settlement amount y can be obtained. By calculating dp / dy from such a characteristic curve, the allowable bearing force P
q or dp / dy of the limit of danger is calculated or can be determined from a table.

After that, for example, when the allowable bearing force Pq is used as a reference, the allowable bearing force Pq can be constantly compared with the measured value every time. It generates a signal to activate a forecast, an alarm, a display device, or the like, or generates a signal to stop or reverse the motion of the associated work implement.

[0018]

According to the present invention, the following functions and effects can be obtained. In a work vehicle provided with an outrigger, it is possible to determine a dangerous sinking of the work vehicle that occurs during normal work only by preparing a few measuring means and a determination device without preparing a special new mechanism. Since the inclination sensor can be used as the settling amount measuring means of the outrigger, the measuring means can be added later, so that the manufacture is easy. Since the reaction force calculating means can use the cylinder pressure of the outrigger, data for other safety devices of the work vehicle can be used, and the versatility of the data is high. If a load sensor is used as the reaction force calculating means, more direct data can be obtained, and the accuracy of the device can be further improved. Even if the grounding member is changed, it is easy to input correction data with a dial. The input of the planar data of the ground contact member is convenient because the data of other devices of the work vehicle, for example, the setting confirmation device can be automatically diverted. Since the numerical index relating to the ground support capacity required by the controller is the allowable ground support capacity, it is possible to judge safe subsidence and subsidence in the danger area. Since the numerical index relating to the bearing capacity of the ground required by the controller is a ratio relating to the contact pressure and the amount of settlement, not only the settlement of the danger area but also the settlement of the process leading to the settlement can be analyzed in detail. The judgment of the controller activates the forecasting or alarm device, so that the danger can be quickly notified to the operator. The judgment of the controller can automatically stop or reverse the operation of the work machine, so that it is safe even if the operator is late in dealing with danger.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a uniform ground contact pressure p and a settlement amount y.

FIG. 2 is an example of a means for obtaining a reaction force of an outrigger.

FIG. 3 is another example of a means for obtaining a reaction force of an outrigger.

FIG. 4 is an example of a means for indirectly calculating a settlement amount.

FIG. 5 is a diagram showing a basic role of a controller.

FIG. 6 shows dp / dy when the ground pressure increases in a time series.
It is a figure showing how to ask for.

FIG. 7 is a diagram showing the relationship between the contact pressure and the amount of settlement when the contact pressure fluctuates in time series.

FIG. 8 is a diagram showing a method of extracting only an appropriate pair of a contact pressure and a settlement amount.

FIG. 9 is a flowchart (flow sheet) of the settlement determination device.

FIG. 10 is an embodiment of the present invention in the case of an H-type outrigger.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D015 GA02 GA03 GB03 3D026 EA06 EA15 EA46 EA50 3F205 AA05 BA01 CA03 DA04 FA02 FA09 HA08 HB02 HC04

Claims (10)

[Claims] 1. An outrigger subsidence amount measuring means, an outrigger reaction force measuring means, a plane data input means of a grounding member at an extension of an outrigger, a numerical value relating to a ground supporting force from output values of the three means. A controller for determining a dangerous settlement by comparing the index with a relation between output values of the three means at all times, and determining a settlement of a work vehicle equipped with an outrigger. apparatus. 2. The apparatus according to claim 1, wherein the outrigger subsidence amount measuring means is an inclination sensor disposed on the outrigger. 3. The determination device according to claim 1, wherein the reaction force measuring means of the outrigger measures the pressure of the outrigger cylinder. 4. The judging device according to claim 1, wherein the reaction force measuring means of the outrigger is a load sensor disposed on an outrigger, a lower portion of an outrigger cylinder, or a grounding member. 5. An input means for inputting planar data of a grounding member,
The determination device according to claim 1, wherein the determination device is an input unit by a human setting operation. 6. The determination device according to claim 1, wherein the input of the planar data of the grounding member is automatically performed. 7. A numerical index relating to a ground support capacity required by a controller is an allowable ground support capacity.
7. The determination device according to any one of 6. 8. The determination device according to claim 1, wherein the numerical index relating to the ground supporting force required by the controller is a ratio relating to a contact pressure and a settlement amount. 9. The judging device according to claim 1, wherein the controller issues an operation command to a forecast or an alarm device when judging dangerous subsidence. 10. The determination device according to claim 1, wherein the controller issues a command to stop or reverse the associated work implement when determining a dangerous subsidence.