Patent Description:
Since a hauling vehicle such as a dump truck that travels with transporting objects loaded thereon sometimes travels on a public road, it is necessary to restrict the loading weight of transporting objects within an allowable weight determined in advance (a maximum loading weight). Therefore, in the case where a hydraulic excavator (a loading machine) that is a construction machine for excavating and loading working objects (transporting objects) such as earth and sand or ore into a hauling vehicle is used to perform a work for loading (a loading work) of the transporting objects into the hauling vehicle, overloading that makes the loading weight excessively heavy in comparison with the maximum loading weight of the hauling vehicle must be avoided.

As a loading overweight prediction device for a construction machine that is used in a loading work, <CIT> discloses a device including average weight calculation means for calculating an average value of a loading weight (an average weight) for each one locating action of a construction machine (loading machine) using a working object weight that is a weight of working objects being transported, remaining time number presentation means for calculating a remaining transport time number until overloading occurs using the remaining weight obtained by removing the total weight of the working objects loaded already from a maximum loading weight of the hauling vehicle and the average value determined by the average weight calculation means and presenting the remaining transport time number, loading weight calculation means for determining the average weight as a next time loading weight, and overweight prediction means for predicting occurrence of overweight (overloading) in next transport when the next time loading weight is greater than the remaining loading weight that is the remaining weight obtained by excepting the total weight of the working objects loaded already from the maximum loading weight.

If the loading weight into the hauling vehicle is made excessively small from the maximum loading weight while avoidance of overloading of the hauling vehicle in a loading work is demanded as described above, then the work efficiency degrades because the transporting objects (working objects) to be transported once by the hauling vehicle decreases. From such a situation as just described, in a loading work by a loading machine, it is desired that transporting objects of a weight equal to the maximum loading weight as much as possible are loaded into the hauling vehicle.

According to the technology of <CIT> mentions above, a remaining loading amount of a hauling vehicle, a weight (a current weight) of transporting objects being transported by a loading machine, an average weight in loading for each one loading action of the loading machine, a remaining loading time number until overloading occurs, and a current loading time number are merely displayed in numerical values on a monitor of the loading machine. Therefore, it is not easy for an operator to intuitively grasp, for example, by what capacity the transporting objects can be scooped up last by the loading machine to make the loading weight of the hauling vehicle closer to the maximum load weight. In other words, from the point of view that the loading weight of the hauling vehicle is made closer to the maximum loading weight without depending upon the skill of the operator, the technology of the document described above has room for improvement.

It is an object of the present invention to provide a construction machine that can make the weight of working objects to be loaded into a hauling vehicle closer to a target value readily.

The above cited problem is solved in accordance with the appended claims.

According to the present invention, since it can be intuitively grasp, on the basis of the illustration of the bucket displayed on the display device, by what capacity the working objects are to be transported by the construction machine such that the loading weight of the hauling vehicle can be made closer to the target value, the working efficiency of the loading work can be improved.

In the following, embodiments of the present invention are described with reference to the drawings.

One of construction machines according the embodiments of the present invention is described with reference to <FIG> and <FIG>. In the present embodiment, a case is described in which a hydraulic excavator is utilized as the construction machine. <FIG> is a side elevational view of the hydraulic excavator to which a load measurement system for a construction machine according to the present embodiment is applied. In the present embodiment, a case is described in which a bucket is used as an attachment to be attached to the arm distal end of a front work implement of a hydraulic excavator and a work of excavating earth and sand (working objects) by the bucket and loading the earth and sand (a loading work) into the cargo bed of a dump track (a hauling vehicle), is repetitively performed.

Referring to <FIG>, the hydraulic excavator <NUM> includes a lower track structure <NUM> having a pair of left and right crawler type track devices provided thereon, an upper swing structure <NUM> mounted to swing at an upper portion of the lower track structure <NUM> with a swing device <NUM> interposed therebetween, a front work implement <NUM> attached to an upper portion of the upper swing structure <NUM> rocking in an upward and downward direction, and a cab <NUM> carried on the upper swing structure <NUM> for being seated by an operator.

The front work implement <NUM> includes a boom <NUM> attached rock in an upward and downward reaction to the upper swing structure <NUM>, an arm <NUM> attached rocking motion to the distal end of the boom <NUM>, a bucket <NUM> attached pivotably to the distal end of the arm <NUM>, a boom cylinder <NUM> (a hydraulic cylinder) for rocking the boom <NUM> upwardly and downwardly, an arm cylinder <NUM> (a hydraulic cylinder) for rocking the arm <NUM>, and a bucket cylinder <NUM> (a hydraulic cylinder) for pivoting the bucket <NUM>. The boom <NUM> is connected to a bracket provided at a front central portion of the upper swing structure <NUM> through a pin and is supported to rock around a fulcrum at the connection portion.

Further, on the upper swing structure <NUM>, a controller (control apparatus) <NUM> for performing various calculations in the load measurement system of the present embodiment, a display device <NUM> that displays a calculation result by the controller <NUM> and so forth, an inputting device <NUM> for allowing an operator to perform inputting of information to the controller <NUM>, a load measurement start switch <NUM> for starting a series of processes by the load measurement system of the present embodiment and a load measurement end switch <NUM> for ending the series of processes by the load measurement system of the present embodiment.

The controller <NUM> has a function for calculating a weight of working objects in the bucket <NUM>, which is executed by a load calculation section <NUM> (see <FIG>) and hereinafter described, and the display device <NUM> displays the weight of the working objects calculated by the controller <NUM>.

The display device <NUM>, the inputting device <NUM>, the load measurement start switch <NUM> and the load measurement end switch <NUM> can be installed in the cab <NUM>. The controller <NUM> may be installed in the cab <NUM> or may be installed at an arbitrary place outside the cab <NUM>.

On the front work implement <NUM>, a posture sensor <NUM> and a pressure sensor <NUM> individually configured from various sensors are provided. The posture sensor <NUM> is a device for detecting the posture of the front work implement <NUM> and is configured from a boom angle sensor <NUM> for detecting the angle of the boom <NUM> with respect to the upper swing structure <NUM>, an arm angle sensor <NUM> for detecting the angle of the arm <NUM> with respect to the boom <NUM> and a bucket angle sensor <NUM> for detecting the angle of the bucket <NUM> with respect to the arm. Meanwhile, the pressure sensor <NUM> is configured from a boom bottom cylinder pressure sensor <NUM> for detecting the hydraulic fluid pressure in the cylinder on the bottom side of the boom cylinder <NUM> and a boom rod cylinder pressure sensor <NUM> for detecting the hydraulic fluid pressure in the cylinder on the rod side of the boom cylinder <NUM>, and a load acting upon the boom cylinder <NUM> is detected on the basis of the hydraulic fluid pressures detected by the sensors <NUM> and <NUM>.

Now, while <FIG> described above is referred to, a system configuration of the load measurement system of the present embodiment is described with reference to <FIG> is a system block diagram of the load measurement system of the present embodiment. It is to be noted that like elements to those of <FIG> are denoted by like reference numerals and description of them is sometimes omitted (this similarly applies also the other figures). The load measurement system of <FIG> includes a controller <NUM>, an inputting device <NUM>, a display device <NUM>, a posture sensor <NUM>, a pressure sensor <NUM>, a load measurement start switch <NUM> and a load measurement end switch <NUM>.

The inputting device <NUM> is, for example, ten keys, a touch panel, a keyboard and so forth and includes a target loading weight setting section <NUM> for performing input setting of a target loading weight P that is a target value of the total weight of working objects to be loaded into a dump track, a bucket shape setting section <NUM> for performing input setting of bucket shape information indicative of a shape of the bucket <NUM>, and a loading time number setting section <NUM> for performing inputting of a set loading time number n indicative of a loading time number (a number of times of a loading work) required for the hydraulic excavator <NUM> before the weight of working objects to be loaded into the dump truck reaches the target loading weight P. From the point of view of maximization of the efficiency of the loading work, preferably the maximum loading weight of the dump truck to be used in the loading work is set to the target loading weight P. The bucket shape information includes information necessary to define a shape of the bucket <NUM> as a vessel mounted on the front work implement <NUM> and can include, for example, dimension information including outer dimensions and inner dimensions of the bucket <NUM>, a cross sectional shape and a cross sectional area perpendicular to a bucket widthwise direction and a bucket widthwise direction length, a maximum weight, a maximum capacity and so forth of working objects capable of being loaded into the bucket <NUM> and so forth. It is to be noted that, in the case where an identifier is set for each of types of buckets and bucket shape information is stored in a tied relationship with each identifier in the controller <NUM> (a storage device <NUM>), a bucket shape may be set indirectly by inputting an identifier of the bucket <NUM> of the front work implement <NUM> as bucket shape information. Such information as the target loading weight P, set loading time number n, bucket shape information and so forth inputted through the inputting device <NUM> are inputted to the controller <NUM>.

The controller <NUM> includes a storage device <NUM> configured from a semiconductor memory (for example, a ROM or a RAM) or a magnetic storage device (a HDD), and a processor not depicted (for example, a CPU or an MPU), and functions as a sensor signal inputting section <NUM>, a load calculation section <NUM>, a loading weight calculation section <NUM> and an illustration creation section <NUM>.

The sensor signal inputting section <NUM> receives, as inputs thereto, output signals of the sensors of the posture sensor <NUM> and the pressure sensor <NUM> provided on the front work implement <NUM>, an output signal of the load measurement start switch <NUM> and an output signal of the load measurement end switch <NUM>, and the controller <NUM> (a processor) converts the format of the input signals into a format necessary for the load calculation section <NUM> to perform calculation.

The load calculation section <NUM> calculates, during action of the front work implement <NUM>, an actual loading weight Wk that is the weight of working objects (earth and sand, ore or the like) in the bucket <NUM> during transportation on the basis of signals from the sensors of the posture sensor <NUM> and the pressure sensor <NUM>, and outputs the calculated actual loading weight Wk to the display device <NUM> and the loading weight calculation section <NUM>. As the calculation method of the actual loading weight Wk, the calculation method of a working object weight W in an embodiment <NUM> of <CIT> is available. In the calculation method of this document, the weight W is calculated on the basis of the weight of the front work implement <NUM> itself, supporting force of the boom cylinder <NUM> calculated from detection values of the pressure sensors <NUM> and <NUM>, a horizontal length between the boom rocking motion center and the bucket gravity center position calculated from detection values of the sensors <NUM>, <NUM> and <NUM> and a horizontal length between the boom rocking motion center calculated from the detection values of the sensors <NUM>, <NUM> and <NUM> and the gravity center position of the front work implement <NUM> excluding the boom cylinder <NUM>. However, the calculation method of the actual loading weight Wk is not restrictive, and a known method that can calculate the working object weight W of working objects in the bucket <NUM> being transported can be utilized.

The loading weight calculation section <NUM> is an element that executes a process for calculating an appropriate loading weight Wa, which is an appropriate value of the weight of working objects to be loaded into a dump truck by a next time loading work by the hydraulic excavator <NUM>. The loading weight calculation section <NUM> in the present embodiment first calculates a remaining loading weight Pa and a remaining loading time number n. The remaining loading weight Pa is a value obtained by subtracting an integrated value (ΣWk, where k, = <NUM>, <NUM>, <NUM>,. ) of the actual loading weight Wk that is the weight of working objects loaded already in the dump truck from the target loading weight P (Pa = P - ΣWk). k indicates a number of times of a loading work having been performed for the dump truck, and the remaining loading time number n is a value obtained by subtracting k from the set loading time number (an initial value of n) inputted by the loading time number setting section <NUM>. Then, the loading weight calculation section <NUM> divides the remaining loading weight Pa by the remaining loading time number n to calculate the appropriate loading weight Wa that is an appropriate value of the weight of the working objects to be loaded into the dump truck by the next time loading work by the hydraulic excavator <NUM> (Wa = Pa/n). In the case where the appropriate loading weight Wa is higher than a bucket maximum weight Wcap of the working objects that can be loaded into the bucket <NUM>, the remaining loading time number n may be incremented by one to calculate the appropriate loading weight Wa again. In this case, it is preferable to repeat this process until the appropriate loading weight Wa becomes lower than the bucket maximum weight Wcap. The appropriate loading weight Wa calculated by the loading weight calculation section <NUM> is outputted to the illustration creation section <NUM>.

The illustration creation section <NUM> creates an appropriate amount illustration <NUM> (see <FIG>), which is an illustration of a state at which working objects of the appropriate loading weight Wa are loaded into the bucket <NUM> having a predetermined posture (hereinafter referred to sometimes as "specific posture") and which illustrates the state of working objects in the bucket <NUM>, on the basis of the appropriate loading weight Wa and the bucket shape information. In the present embodiment, taking how the operator in the cab <NUM> sees the bucket <NUM> into consideration, a state in which the opening face of the bucket <NUM> is held substantially horizontally is set as the specific posture as depicted in <FIG>. In the present specification, the illustration of the bucket <NUM> having the specific posture is referred to as bucket illustration <NUM>, and an illustration where the appropriate amount illustration <NUM> is superimposed on the bucket illustration <NUM> is referred to as target illustration <NUM>. Further, the illustration creation section <NUM> creates the bucket illustration <NUM> on the basis of the bucket shape information, creates the target illustration <NUM> from the bucket illustration <NUM> and the appropriate amount illustration <NUM>, and outputs information for displaying the target illustration <NUM> as a screen image to the display device <NUM>.

<FIG> is an example of an appearance view of the display screen of the display device <NUM> in the present embodiment. Display of the load measurement system of the present embodiment is described with reference to <FIG>. The display device <NUM> displays the appropriate loading weight Wa calculated by the loading weight calculation section <NUM> as a target excavation amount <NUM>, displays the target illustration <NUM> created by the illustration creation section <NUM> (the illustration in which the bucket illustration <NUM> and the appropriate amount illustration <NUM> are displayed in a superimposed relationship), and displays the actual loading weight Wk calculated by the load calculation section <NUM> as an excavation amount <NUM>. Further, the target loading weight P inputted through the target loading weight setting section <NUM> is displayed as a target integrated weight <NUM>, and the set loading time number n inputted through the loading time number setting section <NUM> is displayed as a loading time number <NUM>. Although, in a bucket capacity <NUM> in <FIG>, a maximum weight Wcap of working objects capable of being loaded into the bucket <NUM>, which is calculated on the basis of the bucket shape information and the density ρ1 of the working objects inputted through the bucket shape setting section <NUM>, is displayed for the convenience of illustration, a maximum capacity of working objects that can be loaded into the bucket <NUM> may be displayed with reference to the display of "bucket capacity.

It is to be noted that the display device <NUM> may be made function as the inputting device <NUM> by configuring the display device <NUM> from a touch panel such that a touch with the target integrated weight <NUM> on the screen image causes transition to an input screen image of the target loading weight P. Similarly, a touch with the bucket capacity <NUM> may cause transition to an input screen image for bucket shape information, and a touch with the loading time number <NUM> may cause transition to an input screen image for the set loading time number n.

Now, a flow of calculation in the load measurement system of the present embodiment is described with reference to a flow chart depicted in <FIG>. If the load measurement start switch <NUM> is depressed by an operator, then the controller <NUM> starts a series of processes of <FIG> (step S101). At step S102, a target loading weight P and a loading time number n of a dump truck of a transport destination set by the operator are inputted through the target loading weight setting section <NUM> and the loading time number setting section <NUM>. At step S103, bucket shape information set by the operator is inputted through the bucket shape setting section <NUM>.

At step S104, the illustration creation section <NUM> creates a bucket illustration <NUM> (an illustration of the bucket <NUM> having the specific posture) on the basis of the bucket shape information inputted at step S103. The program may be configured otherwise such that, in the case where the shape of the bucket <NUM> mounted on the front work implement <NUM> is known in advance, the inputting of bucket shape information at step S103 is omitted and the bucket illustration <NUM> stored in advance in the storage device <NUM> is utilized in later processing.

At step S105, the loading weight calculation section <NUM> calculates an appropriate loading weight Wa. In a first operation cycle before working objects are loaded into a dump truck, a value obtained by dividing the target loading weight P inputted at step S102 by the loading time number inputted at step S102 similarly is determined as the appropriate loading weight Wa.

At step S106, it is decided whether or not the appropriate loading weight Wa calculated at step S105 is smaller than the bucket maximum weight Wcap of the working objects capable of being loaded into the bucket <NUM>. Here, in the case where the appropriate loading weight Wa is smaller than the bucket maximum weight Wcap (in the case of YES), the processing advances to step S107. On the contrary, in the case where the appropriate loading weight Wa is equal to or greater than the bucket maximum weight Wcap (in the case of NO), since this indicates that the working objects (earth and sand) cannot fit in the bucket <NUM>, the loading time number n is incremented by one at step S119, and the processing returns to step S105, at which the appropriate loading weight Wa is calculated again.

At step S107, the illustration creation section <NUM> creates an appropriate amount illustration <NUM> on the basis of the bucket shape defined from the bucket shape information and the appropriate loading weight Wa calculated at step S105. The illustration creation section <NUM> in the present embodiment first divides, upon creation of the appropriate amount illustration <NUM>, the appropriate loading weight Wa by the density ρ1 of the working objects set in advance to calculate an appropriate loading capacity Va. Then, the illustration creation section <NUM> defines the shape of the bucket <NUM> as a vessel on the basis of the bucket shape information inputted at step S103 and creates the appropriate amount illustration <NUM> on the basis of how the working objects in the bucket <NUM> when the working objects by the appropriate loading capacity Va are placed in the bucket <NUM> having the specific posture are seen (the appearance of the working objects). In the present embodiment, a quadrangle that appears by crossing of the surface of working objects at the time of placing the working objects of the appropriate loading capacity Va into the bucket <NUM> having the specific posture, with the inner side face of the bucket <NUM> is the appropriate amount illustration <NUM> as depicted in <FIG>, and the working objects at the time are displayed translucently such that the bucket bottom face in the bucket illustration <NUM> is made visible.

At step S109, the illustration creation section <NUM> creates a target illustration <NUM> by superimposition of the bucket illustration <NUM> and the appropriate amount illustration <NUM>. Then at step S110, the target illustration <NUM> is displayed on the display device <NUM>. Consequently, it is possible to allow the operator in the cab <NUM> to intuitively grasp by what degree the working objects are to be placed into the bucket <NUM> by a next time excavation work.

At step Sill, the load calculation section <NUM> calculates an actual loading weight Wk on the basis of signals inputted from the posture sensor <NUM> and the pressure sensor <NUM>, and at step S112, the value of the actual loading weight Wk is displayed as an excavation amount <NUM> on the display device <NUM>.

At step S113, the posture of the front work implement <NUM> is detected from the input signal of the posture sensor <NUM>, and it is decided whether or not the front work implement <NUM> is performing a bucket dumping action. Here, in the case where a bucket dumping action is detected, it is considered that soil discharging action to the dump truck is being performed, and the processing advances to step S114, at which the remaining loading time number is decremented by one. It is to be noted that, although, in the present embodiment, it is decided by detection of a bucket dumping action whether or not a soil discharging action is performed, carrying out of a soil discharging action into the dump truck may be decided by detecting a swinging action in an approaching direction to the dump truck, a change of the actual loading weight Wk in the bucket <NUM>, a change of the loading weight into the dump truck or the like.

At step S115, it is decided whether or not the remaining loading time number reaches zero. Here, in the case where the remaining loading time number is not zero, the processing advances to step S116, at which the integrated loading weight ΣWk is calculated by the load calculation section <NUM>.

At step S117, the loading weight calculation section <NUM> calculates the remaining loading weight Pa (Pa = P - ΣWk). For example, in the case where a loading work is completed once, Pa becomes Pa = P - W<NUM>.

At step S118, k is incremented by <NUM>, and at step S105, the appropriate loading weight Wa is calculated again. For example, in the case where the appropriate loading weight Wa is calculated for the second time, Wa = (P - W<NUM>)/(n - <NUM>) is calculated (n in this expression is the value inputted by the loading time number setting section <NUM>).

On the other hand, in the case where the remaining loading time number is zero at step S115, k is set to the initial value <NUM> at step S120 and the processing of the flow chart is ended (step S121).

According to the load measurement system configured in such a manner as described above, an illustration (the target illustration <NUM>) indicative of a state in which working objects of an appropriate loading weight Wa are placed in the bucket <NUM> having a predetermined posture (the specific posture) on the basis of a value (an appropriate loading capacity Va) obtained by conversion of the appropriate loading weight Wa into a capacity (volume) and the shape of the bucket <NUM> as a vessel mounted currently, and this illustration is displayed on the display device <NUM>. Therefore, the operator can intuitively grasp by what capacity the working objects are to be placed into the bucket <NUM> by a next time loading work. Since this makes it possible to easily make the loading weight of a dump truck closer to the target loading weight P (for example, a maximum loading weight), the working efficiency can be improved.

Further, in the embodiment described above, since the appropriate loading weight Wa and the loading time number are corrected in response to the integrated value (ΣWk) of the actual loading weight Wk, even if the working objects of a weight different from the initial appropriate loading weight Wa are loaded in the middle of a loading work, the final loading weight of the dump truck can be made closer to the target loading weight P.

Now, another embodiment of the present invention is described. In the present embodiment, bucket illustrations according to bucket shape information are stored in the storage device <NUM> in advance, and appropriate amount illustrations <NUM> of buckets each corresponding to the respective ratios Wb that are ratios of the appropriate loading weight to a maximum weight (hereinafter referred to "bucket capacity" for the convenience of description) Wcap of working objects that can be loaded into the bucket are stored in advance in the storage device <NUM>. In particular, a plurality of appropriate amount illustrations <NUM> according to bucket shapes and the ratios Wb are stored in the storage device <NUM>. The hardware configuration of the other part is same as that depicted in <FIG> and <FIG>, and also the screen image of the display device <NUM> is same as that of <FIG>.

In the following, a flow of calculation of the load measurement system in the present embodiment is described with reference to a flow chart depicted in <FIG>. If the load measurement start switch <NUM> is depressed by the operator, then the controller <NUM> starts processing of <FIG> (step S1). At step S2, the target loading weight setting section <NUM> and the loading time number setting section <NUM> input a target loading weight P and a loading time number n for a dump truck.

At step S3, bucket shape information set by the operator is inputted through the bucket shape setting section <NUM>. At step S4, the illustration creation section <NUM> recalls a bucket illustration <NUM> according to the bucket shape information inputted at step S103, from the storage device <NUM>.

At step S5, the loading weight calculation section <NUM> calculates an appropriate loading weight Wa. Then at step S32, it is decided whether or not the appropriate loading weight Wa is smaller than the bucket capacity Wcap. For the bucket capacity Wcap, a value suitable as the bucket capacity of the bucket <NUM> at present is selected on the basis of the bucket shape information from within the storage device <NUM>. Here, in the case where it is decided that the appropriate loading weight Wa is smaller than the bucket capacity Wcap, the processing advances to step S6. On the contrary, in the case where it is decided that the appropriate loading weight Wa is equal to or greater than the maximum weight Wcap, the loading time number n is increased by one at step S33, whereafter the processing returns to step S5 to calculate the appropriate loading weight Wa again.

At step S6, the illustration creation section <NUM> calculates the ratio Wb between the bucket capacity Wcap and the appropriate loading weight Wa, and at step S8, the illustration creation section <NUM> recalls an appropriate amount illustration <NUM> according to the ratio Wb from the storage device <NUM>.

At step S9, the illustration creation section <NUM> superimposes the bucket illustration <NUM> recalled at step S4 and the appropriate amount illustration <NUM> recalled at step S8 to create a target illustration <NUM> and outputs the target illustration <NUM> to the display device <NUM>, and at step S10, the target illustration <NUM> is displayed on the screen of the display device <NUM>.

At step S11, the load calculation section <NUM> calculates an actual loading weight Wk on the basis of signals inputted from the posture sensor <NUM> and the pressure sensor <NUM>, and at step S12, the value of the actual loading weight Wk is displayed as the excavation amount <NUM> on the display device <NUM>.

At step S13, it is decided whether or not the load measurement end switch <NUM> is depressed. In the case where the load measurement end switch <NUM> is depressed (in the case of YES), load measurement is to be stopped and the processing advances to step S14, at which the processing for load measurement is ended. On the contrary, in the case where the load measurement end switch <NUM> is not depressed (in the case of NO), the remaining loading time number is decremented by one at step S34. Then at step S35, it is decided whether or not the remaining loading time number n is zero, and in the case where the remaining loading time number is <NUM> (in the case of YES), the processing advances to step S14, at which the processing ended. On the other hand, in the case where the remaining loading time number is any other than zero (in the case of NO), the processing returns to step S5 to repeat the succeeding processes.

It is to be noted that the flow may be configured otherwise such that, in the case where the decision at step S13 is NO, by executing step S113 of <FIG> before the processing advances to step S34, it is decided whether or not loading of the working objects into the dump truck is completed, and after it is decided as YES here, the processing advances to step S34.

Also in the embodiment configured in such a manner as described above, the operator can intuitively grasp by what capacity working objects are to be placed into the bucket <NUM> by a next time loading work. Especially, in the present embodiment, since bucket illustrations <NUM> prepared according to bucket shape information and appropriate amount illustrations <NUM> of buckets each prepared for individual bucket capacities Wcap and ratios Wb of the appropriate loading weight are stored in the storage device <NUM> in advance, it is a merit that the calculation load to the controller <NUM> involved in creation of a bucket illustration <NUM> and an appropriate amount illustration <NUM> (in short, creation of a target illustration <NUM>) can be reduced significantly from that of the example of <FIG>.

It is to be noted that the bucket capacity Wcap not only can be inputted as bucket shape information through the bucket shape setting section <NUM> but also can be calculated from other bucket shape information and besides can be stored in advance in the storage device <NUM> for each of types of the buckets <NUM> and recalled on the basis of bucket shape information. This similarly applies also to the other embodiments that utilize the bucket capacity Wcap.

Now, a further embodiment of the present invention is described. <FIG> is a system block diagram of a further load measurement system of the present invention; <FIG> is an appearance view of the display screen of a display device <NUM> of the present embodiment; and <FIG> is a flow chart of calculation processing in the load measurement system of the present embodiment. In those figures, like elements and like steps to those in the preceding figures are denoted by like reference characters. In the following description, description of like elements and like steps to those described hereinabove is omitted, and description is given focusing on differences.

First, description is given with reference to <FIG>. The controller <NUM> in the present embodiment functions as an upper and lower limit weight calculation section <NUM>. Also in the present embodiment, bucket illustrations according to bucket shape information are stored in advance in the storage device <NUM>, and an appropriate amount illustration of each bucket is stored in the storage device <NUM> for each of ratios Wb between maximum weights (bucket capacities) Wcap and appropriate loading weights of working objects capable of being loaded into the bucket.

The upper and lower limit weight calculation section <NUM> calculates an appropriate upper limit weight Wup, which is an allowable upper limit value of the weight of working objects to be loaded into a dump truck by a single time loading work on the basis of an appropriate loading weight Wa and an upper limit coefficient Aup that is a predetermined value equal to or greater than <NUM>, and calculates an appropriate lower limit weight Wlo, which is an allowable lower limit value of the weight of working objects to be loaded into a dump truck by a single time loading work, on the basis of the appropriate loading weight Wa and a lower limit coefficient Alo that is a predetermined value equal to or lower than <NUM>.

The upper and lower limit weight calculation section <NUM> in the present embodiment calculates the appropriate upper limit weight Wup in the following manner. First, the upper and lower limit weight calculation section <NUM> acquires a bucket capacity Wcap on the basis of bucket shape information inputted through the bucket shape setting section <NUM> and receives, as an input thereto, an appropriate loading weight Wa from the loading weight calculation section <NUM>. Then, the upper and lower limit weight calculation section <NUM> multiplies the input appropriate loading weight Wa by the upper limit coefficient Aup to calculate an appropriate upper limit weight Wup. In the case where the appropriate upper limit weight Wup is greater when the appropriate upper limit weight Wup and the bucket capacity Wcap are compared with each other, the upper and lower limit weight calculation section <NUM> outputs the bucket capacity Wcap as the appropriate upper limit weight Wup to the illustration creation section <NUM>. On the contrary, in the case where the bucket capacity Wcap is greater, the upper and lower limit weight calculation section <NUM> outputs the appropriate upper limit weight Wup to the illustration creation section <NUM>. It is to be noted that, as the upper limit coefficient Aup, one or more arbitrary values equal to or greater than <NUM> can be set and stored in advance in the storage device <NUM>.

Further, the upper and lower limit weight calculation section <NUM> in the present embodiment calculates the appropriate lower limit weight Wl0 in the following manner. The upper and lower limit weight calculation section <NUM> multiplies the appropriate loading weight Wa inputted from the loading weight calculation section <NUM> by the lower limit coefficient Alo to calculate an appropriate lower limit weight Wlo and outputs the appropriate lower limit weight Wlo to the illustration creation section <NUM>. It is to be noted that, as the lower limit coefficient Alo, one or more arbitrary values equal to or lower than <NUM> can be stored in advance in the storage device <NUM>.

The illustration creation section <NUM> calculates an upper limit ratio Wbup (Wbup = Wup/Wcap) that is a ratio of the appropriate upper limit weight Wup to the bucket capacity Wcap, recalls an appropriate amount illustration <NUM> according to the upper limit ratio Wbup from the storage device <NUM>, and determines the appropriate amount illustration <NUM> as an appropriate amount upper limit illustration <NUM>. Further, the illustration creation section <NUM> calculates a lower limit ratio Wblo (Wblo = Wlo/Wcap) that is a ratio of the appropriate upper limit weight Wlo to the bucket capacity Wcap, recalls an appropriate amount illustration <NUM> according to the lower limit ratio Wbup from the storage device <NUM> and determines the appropriate amount illustration <NUM> as an appropriate amount lower limit illustration <NUM>. Then, the illustration creation section <NUM> superimposes the appropriate amount upper limit illustration <NUM> and the appropriate amount lower limit illustration <NUM> on the displayed bucket illustration <NUM> to create a target illustration <NUM>, outputs the created target illustration <NUM> to the display device <NUM> and displays the target illustration <NUM> on the display device <NUM>.

<FIG> is an example of an appearance view of a display screen image of the display device <NUM> in the present embodiment. The display device <NUM> in the present embodiment displays the target illustration <NUM> created by the illustration creation section <NUM> and having the bucket illustration <NUM>, appropriate amount upper limit illustration <NUM> and appropriate amount lower limit illustration <NUM> superimposed therein. In the appropriate amount upper limit illustration <NUM>, a quadrangle that appears when the surface of working objects of the appropriate upper limit weight Wup crosses with an inner side face of the bucket <NUM> is indicated by a solid line, and in the appropriate amount lower limit illustration <NUM>, a similar quadrangle is indicated by a broken line.

Now, a flow of calculation in the load measurement system of the present embodiment is described with reference to a flow chart depicted in <FIG>. It is to be noted that, at steps S2, S3, S4 and S5, at steps S10, S11, S12 and S13 and at steps S34, S35 and S14 in <FIG>, processes same as those in <FIG> are performed. Also it is possible to configure the flow of calculation such that, after step S5 of <FIG>, the decision at step S32 of <FIG> is performed and, when the decision is NO, step S33 is executed and the processing returns to step S5, but when the decision is YES, the processing advances to step S15.

At step S15, the upper and lower limit weight calculation section <NUM> multiplies the appropriate loading weight Wa by the upper limit coefficient Aup to calculate an appropriate upper limit weight Wup, and at step S16, it is decided whether or not the appropriate upper limit weight Wup is smaller than the bucket capacity Wcap.

In the case where it is decided at step S16 that the appropriate upper limit weight Wup is smaller than the bucket capacity Wcap (in the case of YES), the processing advances directly to step S18. On the contrary, in the case where it is decided at step S16 that the appropriate upper limit weight Wup is greater than the bucket capacity Wcap (in the case of NO), the appropriate upper limit weight Wup and the bucket capacity Wcap are made equal to each other (step S17), whereafter the processing advances to step S18.

At step S18, the upper and lower limit weight calculation section <NUM> multiplies the appropriate loading weight Wa by the lower limit coefficient Alo to calculate an appropriate lower limit weight Wlo.

At step S19, the illustration creation section <NUM> calculates the ratio Wbup between the bucket capacity Wcap and the appropriate upper limit weight Wup, and at step S21, the illustration creation section <NUM> recalls an appropriate amount illustration <NUM> corresponding to the ratio Wbup as an appropriate amount upper limit illustration <NUM> from the storage device <NUM>.

Then at step S22, the illustration creation section <NUM> calculates the ratio Wblo between the bucket capacity Wcap and the appropriate lower limit weight Wlo, and at step S24, the illustration creation section <NUM> recalls an appropriate amount illustration <NUM> corresponding to the ratio Wblc as an appropriate amount lower limit illustration <NUM> from the storage device <NUM>.

At step S25, the illustration creation section <NUM> creates a target illustration <NUM> in which the bucket illustration <NUM> created at step S4, the appropriate amount upper limit illustration <NUM> created at step S21 and the appropriate amount lower limit illustration <NUM> crated at step S24 are superimposed and outputs the target illustration <NUM> to the display device <NUM>, and at step S10, the target illustration <NUM> is displayed on the screen of the display device <NUM>. The succeeding processes are same as those of the flow chart of <FIG>.

Also in the embodiment configured in such a manner as described above, it is possible to allow the operator to intuitively grasp by what capacity the working objects are to be placed into the bucket <NUM> by a next time loading work. Especially in the present embodiment, since the upper limit weight Wup and the lower limit weight Wlo are provided for the appropriate loading weight, even in the case where the appropriate loading weight has a predetermined allowable width, the operator can intuitively grasp by what amount the working objects are to be placed into the bucket <NUM> by a next time excavation work.

It is to be noted that, although, in the present embodiment, an appropriate amount upper limit illustration <NUM> and an appropriate amount lower limit illustration <NUM> are recalled from the storage device <NUM> on the basis of the two ratios Wbup and Wblo, an appropriate amount upper limit illustration <NUM> and an appropriate amount lower limit illustration <NUM> may be created on the basis of volumes calculated from the appropriate upper limit weight Wup and the appropriate lower limit weight Wlo, respectively, as in the case of the example of <FIG>.

Further, the inputting device <NUM> is preferably configured such that an upper limit coefficient Aup and a lower limit coefficient Alo of values desired by an operator can be inputted. <FIG> is an appearance view of a display screen image in the case where the display device <NUM> is configured from a touch panel in order to use the display device <NUM> as the inputting device <NUM>. The display screen image of <FIG> has an upper limit allowable amount inputting portion <NUM> and a lower limit allowable amount inputting portion <NUM>. If the upper limit allowable amount inputting portion <NUM> and the lower limit allowable amount inputting portion <NUM> are touched by the operator, then a numerical value inputting dialog (not depicted) stands up on the screen to make it possible to input an upper limit allowable amount X and a lower limit allowable amount Y on the screen image. The upper limit coefficient Aup and the lower limit coefficient Alo are determined utilizing the inputted values X and Y (integers equal to or greater than zero but equal to or smaller than <NUM>), and relational expressions representing the upper limit coefficient Aup and the lower limit coefficient Alo represented by X and Y (particularly, relational expressions of upper limit coefficient Aup = (<NUM> + X)/<NUM> and lower limit coefficient Alo = (<NUM> - Y)/<NUM>). If the system is configured such that the operator can set the upper limit weight Wup and the lower limit weight Wlo in this manner, then even in the case where the dump truck into which working objects is to be loaded changes and the allowable value of the appropriate loading weight changes, advantages similar to those of the present embodiment can be achieved.

Now, a still further embodiment of the present invention is described. <FIG> is a system block diagram of a load measurement system of the present embodiment; <FIG> is an appearance view of a display screen of a display device <NUM> in the present embodiment; and <FIG> is a flow chart of calculation processing in the load measurement system of the present embodiment. In the following description, description of like elements and like steps to those in the preceding figures denoted by like reference characters is omitted, and description is given focusing on differences.

First, description is given with reference to <FIG>. Although, in the preceding embodiments, the load calculation section <NUM> is connected to the display device <NUM>, in the present embodiment, the load calculation section <NUM> is further connected to the illustration creation section <NUM>. The load calculation section <NUM> outputs a calculated actual loading weight Wk to the illustration creation section <NUM>.

The illustration creation section <NUM> calculates a ratio Wc (Wc = Wk/Wcap) that is a ratio of the actual loading weight Wk to the bucket capacity Wcap. The illustration creation section <NUM> reads out an appropriate amount illustration <NUM> corresponding to the ratio Wc from the storage device <NUM>, determines the appropriate amount illustration <NUM> as an actual loading amount illustration <NUM> and outputs a result of superimposition (a result illustration <NUM>) of the actual loading amount illustration <NUM> on the target illustration <NUM> (the bucket illustration <NUM> and the appropriate amount illustration <NUM>) to the display device <NUM>. Consequently, the result illustration <NUM> is displayed as depicted in <FIG> at the display device <NUM>.

<FIG> is an example of an appearance view of the display screen of the display device <NUM> in the present embodiment. The display device <NUM> in the present embodiment displays a result illustration <NUM> in which a bucket illustration <NUM>, an appropriate amount illustration <NUM> and an actual loading amount illustration <NUM> created by the illustration creation section <NUM> are superimposed.

Now, a flow of calculation in the load measurement system of the present embodiment is described with reference to a flow chart depicted in <FIG>. First, processes at step S1 to step S12 same as those of <FIG> are performed. Then at step S28, the illustration creation section <NUM> calculates a ratio Wc (Wc = Wk/Wcap) that is a ratio of the actual loading weight Wk to the bucket capacity Wcap, and at step S29, the illustration creation section <NUM> recalls an appropriate amount illustration <NUM> corresponding to the ratio Wc as an actual loading amount illustration <NUM> from the storage device <NUM>. Then at step S30, the illustration creation section <NUM> superimposes the target illustration <NUM> and the actual loading amount illustration <NUM> to create a result illustration <NUM>. At step S31, the display device <NUM> displays the result illustration <NUM>. Succeeding processes are same as those in the flow chart of <FIG>.

Also with the embodiment configured in such a manner as described above, it is possible to allow the operator to intuitively grasp by what capacity the working objects are to be placed into the bucket <NUM> by a next time excavation work. Especially, in the present embodiment, since the appropriate amount illustration <NUM> indicative of a target value of the working objects and the actual loading amount illustration <NUM> indicative of an actual amount are displayed together, the accuracy of the loading work (excavating work) of the working objects into the bucket <NUM> can be fed back immediately to the operator. Consequently, a chance for improvement in skill can be provided to the user, and further, also improvement in working efficiency in the future can be anticipated.

Now, a yet further embodiment of the present invention is described. <FIG> is a system block diagram of a load measurement system of the present embodiment; <FIG> is an appearance view of the display screen of the display device <NUM> of the present embodiment; and <FIG> is a flow chart of calculation processing in the load measurement system of the present embodiment. In the following description, description of like elements and like steps to those in the preceding figures denoted by like reference characters is omitted, and description is given focusing on differences.

First, description is given with reference to <FIG>. The inputting device <NUM> in the present embodiment is different from those in the other embodiments in that it functions as a sticking and falling weight setting section <NUM>. The sticking and falling weight setting section <NUM> is an element for inputting a sticking weight Wf that is the weight of working objects (sticking matters) that stick to and are not discharged from the bucket <NUM>, and a falling weight Wd indicative of the weight of working objects (falling matters) spilling down from the bucket <NUM> upon loading into a dump truck (for example, during swinging). From the point of view of making the loading weight into a dump truck closer to a target loading weight P, creation of a target illustration <NUM> and calculation of an actual loading weight Wk taking the weights Wf and Wd of sticking matters and falling matters into consideration is preferable. The sticking weight Wf and the falling weight Wd inputted to the operator through the inputting device <NUM> (the sticking and falling weight setting section <NUM>) are outputted to the load calculation section <NUM> and the illustration creation section <NUM> in the controller <NUM>. It is to be noted that only one of the sticking weight Wf and the falling weight Wd may be inputted, and in the case where only one of them is inputted, it is sufficient if the other is set to zero.

<FIG> is an example of an appearance view of the display screen image of the display device <NUM> in the present embodiment. The display device <NUM> in the present embodiment displays a target illustration 31A in which a bucket illustration <NUM> and a corrected appropriate amount illustration 30A created by the illustration creation section <NUM> are superimposed. Further, the display device <NUM> in the present embodiment is configured from a touch panel so as to be utilized as the inputting device <NUM>. The display screen of <FIG> has a sticking weight inputting section <NUM> and a falling weight inputting section <NUM>. If the sticking weight inputting section <NUM> and the falling weight inputting section <NUM> are touched by the operator, then a numerical value inputting dialog (not depicted) pops up on the screen to enable inputting of a sticking weight Wf and a falling weight Wd on the screen. The inputted sticking weight Wf and falling weight Wd are outputted to the load calculation section <NUM> and the illustration creation section <NUM> in the controller <NUM>.

Now, a flow of calculation of the load measurement system in the present embodiment is described with reference to a flow chart depicted in <FIG>. First, processes at steps S1 to S5 and steps S32 and S33 same as those in <FIG> are performed.

At step S171, the illustration creation section <NUM> calculates a total value Ws of an appropriate loading weight Wa, a sticking weight Wf and a falling weight Wd. Then, the illustration creation section <NUM> calculates a ratio Wg between the bucket capacity Wcap and the total value Ws at step S172 and recalls an appropriate amount illustration <NUM> corresponding to the ratio Wg as a corrected appropriate amount illustration 30A from the storage device <NUM> at step S173.

At step S174, the illustration creation section <NUM> creates a target illustration 31A in which the bucket illustration <NUM> created at step S4 and the corrected appropriate amount illustration 30A created at step S173 are superimposed and outputs the target illustration 31A to the display device <NUM>, and at step S10, the target illustration 31A is displayed on the screen of the display device <NUM>.

At step S11, the load calculation section <NUM> calculates an actual loading weight Wk on the basis of the signals inputted from the posture sensor <NUM> and the pressure sensor <NUM>, and at step S175, a value obtained by subtracting the total value of the sticking weight Wf and the falling weight Wd from the actual loading weight Wk (the corrected actual loading weight W'k = Wk - (Wf + Wd)) is displayed in the excavation amount <NUM> of the display device <NUM>. Succeeding processes are same as those of the flow chart of <FIG>.

It is to be noted that, in the case where an integrated loading weight is utilized when an appropriate loading weight Wa for a next cycle is calculated as in the case of the flow chart depicted in <FIG>, it is preferable to calculate not an integrated value of the actual loading weight Wk but an integrated value (ΣW'k) of the corrected actual loading weight W'k.

Also in the embodiment configured in such a manner as described above, it is possible to allow the operator to intuitively grasp by what capacity the working objects are to be placed into the bucket <NUM> by a next time excavation work. Especially, in the present embodiment, since an illustration (a corrected appropriate amount illustration 30A) of working objects whose capacity is corrected to a rather great amount taking the weight of the working objects that are not discharged to the cargo bed of a dump truck (the sticking weight Wf and the falling weight Wd) into consideration, is displayed on the display device <NUM>, such a situation that the loading weight of the dump truck becomes lower than an estimated value because of sticking matters or falling matters can be prevented, and degradation of the working efficiency can be prevented.

Although, in the embodiments described above, a view (a perspective view) of the bucket <NUM> held in the specific posture as viewed from the cab <NUM> is adopted as the bucket illustration <NUM>, a view of the bucket <NUM> held in the specific posture as viewed from a side (a side elevational view) as depicted in <FIG> of the bucket <NUM>, may be adopted as the bucket illustration, or a view as viewed from any other point of view may be adopted as the bucket illustration.

Further, although, in the embodiments described above, an appropriate amount illustration <NUM> is created assuming that the surface of working objects in the bucket <NUM> is a flat face, an appropriate amount illustration <NUM> may be created otherwise assuming that working objects are piled up with predetermined gradients from forward, rearward, leftward and rightward directions of the bucket <NUM> as depicted in <FIG>. In the example of the appropriate amount illustration <NUM> of <FIG>, the shape of the piled working objects is represented by contour lines, and regions surrounded by the contour lines are presented by different colors.

Further, the target illustration <NUM> or the result illustration <NUM> may be created in the following manner. In particular, a three-dimensional model of the bucket <NUM> is created on the basis of bucket shape information, and a state in which working objects of the appropriate loading weight Wa are placed in the bucket <NUM> of the three-dimensional model is simulated. Then, the target illustration <NUM> or the result illustration <NUM> is created on the basis of a view when the state mentioned is viewed from a predetermined direction. Further, the "predetermined direction" in this case is preferably configured so as to be suitably changed to a desired direction by the operator, and also the specific posture of the bucket <NUM> at the time is preferably configured for suitable change to a posture desired by the operator.

The present invention can be applied not only to a hydraulic excavator utilized for explanation in the foregoing description of the embodiments but also to construction machines that perform excavation and loading by a front work implement such as a wheel loader. Further, while, in the embodiments described above, it is described that the hauling vehicle is a dump track, for example, also a large-sized truck or some other self-propelled construction machine that can carry luggage can be utilized.

Further, the present invention is not limited to the embodiments described above and includes various modifications without departing from the subject matter thereof. For example, the present invention is not limited to configurations that include all components described in connection with the embodiments described above and includes also configurations in which part of the components is deleted. Further, it is possible to add or substitute part of the components of a certain embodiment to or with the components of a different embodiment.

Claim 1:
A construction machine (<NUM>), comprising:
a work implement (<NUM>) including a bucket (<NUM>);
a controller (<NUM>) configured to calculate a weight of working objects in the bucket (<NUM>); and
a display device (<NUM>) configured to display the weight of the working objects calculated by the controller (<NUM>), characterized in that:
the controller (<NUM>)
calculates, based on a target loading weight (P) that is a target value of a total weight of working objects to be loaded into a hauling vehicle, a set loading time number indicative of a loading time number required for the construction machine (<NUM>) before the target loading weight (P) is reached, a loading weight of the working object that is a value of the weight of the working objects to be loaded into the hauling vehicle by a single time loading work of the set loading time number,
creates an illustration that is an illustration of an appearance of the working objects of the loading weight of the working objects loaded into the bucket (<NUM>) having a predetermined posture and that illustrates the state of the working objects in the bucket (<NUM>), based on the loading weight of the working object and the bucket shape information indicating shape of the bucket (<NUM>),
creates a target illustration (<NUM>) indicating a capacity of the working object to be loaded into the bucket (<NUM>) at next work object loading work by superimposing an illustration of the bucket (<NUM>) having the predetermined posture and an illustration of the appearance of the working object, and
controls the display device (<NUM>) to display the target illustration (<NUM>).