JP2015040422A - Display device of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device of a construction machine capable of promoting optimum operation that leads to efficient excavation work for an inexperienced operator.SOLUTION: A traction force value and a lift force value of an actual excavation work are displayed on display parts (72, 73) in contradistinction to a target traction force value and a target lift force value for a preset excavation work, respectively, in accordance with an operation state (operation amount) of each of a first operation part for operating a traction force of a car body and a second operation part for commanding and operating a work machine at a front part of the car body. By visually observing actual traction force value and lift force value relative to the target traction force value and the target lift force value, an operator is promoted to make an operation for improved fuel cost and work efficiency in respective steps of work (travel of a vehicle, lift of the work machine).

Description

  The present invention relates to a display device for a construction machine that performs excavation work by operating a bucket.

  Some construction machines that perform excavation work such as a wheel loader use a work vehicle in which a bucket is assembled to be movable up and down at the front of a work vehicle on which an operator can board. The excavation work of the work vehicle is usually performed by an accelerator operation or a lever operation by an operator.

  Specifically, excavation work is carried out by driving a work vehicle by operating an accelerator pedal, and rushing a bucket with a loading / unloading port forward along the ground, for example, into a work to be excavated such as a pile of sediment to be processed. Load the work to be drilled into the bucket. When loading of the excavated object is completed, this operation is performed by a series of operations such as lifting the bucket while moving the bucket to an upward posture by operating the lever for lifting the bucket.

  By the way, the skilled operator can proceed with the excavation work by an operation that provides an operation with good fuel efficiency and high work efficiency based on a rule of thumb. However, when an unskilled operator performs an excavation work, the excavation may sometimes be advanced by an operation with poor fuel consumption or work efficiency due to lack of proficiency. For this reason, even in a work vehicle for a construction machine, recognition of whether or not an excavation operation is being performed efficiently is being demanded in order to improve fuel consumption, as in the case of automobiles and the like.

  For example, in Patent Document 1, in a hydraulic excavator, the excavation force used for excavation is obtained from the rotation angle of a bucket, the pressure of a hydraulic cylinder, and the like, and the numerical value obtained by comparing the excavation force with a reference excavation force that is a criterion for determination. Is disclosed.

JP-A-2-30822

  However, since the above-described conventional technique is configured to display the actual excavation force along with the reference excavation force as a numerical value, it is difficult to determine which operation lever is operated to what extent to perform efficient excavation work. .

  For example, excavation work using a wheel loader is performed by combining different operation systems, such as a bucket entering a soil by a forward operation of a work vehicle or a bucket loaded with soil by a lift operation. The operation when entering the earth and sand and the operation of lifting the bucket loaded with earth and sand are involved. For this reason, it is difficult to prompt an unfamiliar operator to improve the fuel consumption or to operate with high work efficiency simply by displaying the excavation force as a numerical value.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a display device for a construction machine that can encourage an operator who is unfamiliar with the operation to perform an optimum operation that brings about an efficient excavation work.

  In order to achieve the above object, a first aspect of the present invention provides a vehicle body having wheels, a work machine provided at a front portion of the vehicle body, a first operation unit provided on the vehicle body for operating a traction force of the vehicle body, A display device for a construction machine that has a second operation unit that commands and operates an operation, and that performs excavation work by operating the first operation unit and the second operation unit, and calculates a tractive force in the excavation work And a lift force calculation unit for calculating the lift force of the work machine in excavation work, and comparing the calculated traction force value and lift force value with the preset target traction force value and target lift force value of the excavation work, respectively. The first comparison unit and the first display unit for displaying the comparison results of the first comparison unit are provided.

  The invention of claim 2 is provided with a selection unit provided so that the upper limit of the traction force and the lift force can be selected in advance according to different work loads, and the target traction force value and the target lift force value are respectively selected based on the selection by the selection unit. It was configured to be set.

  The invention of claim 3 further includes a first excavation force calculation unit for calculating an excavation force represented by a resultant force of both the calculated traction force value and the calculated lift force value, and an excavation object loaded on the work implement. A loading weight detection unit that detects a loading weight of the object, a second excavation force calculation unit that calculates a drilling force per unit weight based on the calculated excavation force and the detected loading weight, and a calculated per unit weight A second comparison unit that compares the excavation force value with a target excavation force value per unit weight set in advance according to the loading specification of the work implement; and a second display unit that displays a comparison result of the second comparison unit It was.

  According to a fourth aspect of the present invention, the second excavation force calculation unit further determines the excavation force per unit weight from the start of the excavation operation in which the work to be excavated is loaded onto the work implement to the end of the excavation operation to finish the lift of the work implement. The average value was calculated, and the second comparison unit contrasted the average value of the excavation force per unit weight from the start of the excavation work to the end of the excavation work with the target excavation force value per unit weight.

  In the invention of claim 5, the average value of the digging force per unit weight used in the second comparison unit accumulates the values from the value at the latest excavation work to the number of past excavation work, The cumulative average excavation force value per unit weight divided by the number of excavation operations up to.

  According to the invention of claim 1, during excavation work that makes full use of different operation systems, the traction force (traveling driving force) of the vehicle body and the lift force of the work implement are displayed in real time on the first display unit, Each is displayed while comparing with the target lift force value. As a result, the operator can visually check the quality of the operation at each stage of work (travel of the vehicle, lift of the work machine).

In addition, the target traction force value, the actual traction force value with respect to the target lift force value, and the lift force value can be visually recognized in association with the respective operation states of the first operation unit and the second operation unit. The work (running of the vehicle, lift of the work machine) can improve the fuel efficiency and promote the operation with high work efficiency.
Therefore, it is possible to prompt an operator who is unfamiliar with the operation to perform an optimum operation that brings about efficient excavation work.

  According to the invention of claim 2, when the traction force and the lift force that exert the force corresponding to the work load are selected by the selection unit, the target traction force value and the target lift force value are displayed in accordance with the selection. The operator can be encouraged to perform the optimum operation regardless of the work load.

  According to the invention of claim 3, in addition to prompting the operator to perform a good operation at each stage of the excavation work, the second display unit allows the operator to perform the work efficiently using the excavation capability of the work machine. It can be recognized whether or not there is. Thereby, the operator can be urged to perform an optimum operation from a comprehensive viewpoint, and the excavation work can be carried out comprehensively and efficiently.

According to the invention of claim 4, the excavation force per unit weight is an average value specialized from the start of excavation work in which the work to be excavated is loaded onto the work implement to the end of the excavation work to finish the lift of the work implement. The work efficiency can be recognized with easy-to-read displays specialized for excavation work.
According to the invention of claim 5, work efficiency can be recognized with an easy-to-see display specialized only for excavation work in consideration of past work situations.

The side view of the wheel loader which is an example of the construction machine which concerns on the 1st Embodiment of this invention. The block diagram which shows the traveling drive system of a wheel loader, and a bucket drive system. (A) is a top view which shows the location of the various apparatuses in the driving | running | working room of a wheel loader, (b) is a top view of the switch for switching the work mode among the apparatus. The diagram for demonstrating the output characteristic of an engine. The diagram which shows the speed stage characteristic of a transmission. The side view of the bucket explaining the excavation work performed with a wheel loader in order. Explanatory drawing which shows the relationship of the traction force, the lift force, and excavation force during excavation work. The block diagram which shows the structure of each part of the display apparatus which displays the condition of excavation work. The figure which shows an example of the display screen in bucket pulling operation by the display apparatus. The figure which shows an example of the display screen during bucket lift operation by the display apparatus. The figure which shows the example of a different display of the display apparatus used as the principal part of the 2nd Embodiment of this invention. The figure which shows the example of a display which displayed the log | history of excavation force.

Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.
FIG. 1 shows a side view of a construction machine, for example, a wheel loader, FIG. 2 shows a traveling drive system and a bucket drive system of the wheel loader, and FIG. 3 (a) shows various operation devices in a cab 6 of the wheel loader. The layout is shown.

  First, the entire wheel loader will be described. In the figure, reference numeral 1 denotes a work vehicle constituting the wheel loader. A vehicle body 1x of the work vehicle 1 includes a front vehicle body portion 5 having a work implement 21 and a rear vehicle body portion 9 having an operator cab 6 and an engine compartment 7 on which an operator is boarded in a vehicle width direction via a center pin 12. It is configured to be able to bend (turn). The front vehicle body portion 5 is provided with a front wheel 4, and the rear vehicle body portion 9 is provided with a rear wheel 8 (both corresponding to the wheels of the present application). Further, the front vehicle body portion 5 and the rear vehicle body portion 9 are respectively connected to steering cylinders 13 (partially shown in FIG. 1) disposed on both sides of the center pin 12 so that the work vehicle 1 is centered on the center pin 12. It can be bent left and right in the vehicle width direction.

  The work machine 21 is configured such that the excavating bucket 3 is provided at the front portion of the front vehicle body portion 5 so as to be movable up and down. Specifically, the work machine 21 includes a lift arm 2 that is supported so as to be able to move up and down extending forward from the front portion of the front body portion 5, and a bucket that is rotatably supported in the vertical direction at the tip portion of the lift arm 2. 3, an arm cylinder 10 (hydraulic actuator) for raising and lowering the lift arm 2, a bucket cylinder 11 (hydraulic actuator) for driving the bucket, and an output of the bucket cylinder 11 is transmitted to the bucket 3 to rotate the bucket 3. And a link mechanism 11a.

  In the engine room 7, the engine 14 and other devices connected to, for example, the output portion of the engine 14 are housed (shown in FIG. 2). Specifically, a working hydraulic pump 19 with a regulator 23, a torque converter 15 (a fluid clutch composed of an impeller, a turbine, and a stator), a solenoid valve 16a and a hydraulic clutch (not shown) are provided in the engine chamber 7. The attached transmission 16 is accommodated.

  A working hydraulic pump 19, a torque converter 15, and a transmission 16 are sequentially connected to the output portion of the engine 14. The output portion of the transmission 16 is connected to the front and rear differential gears 17 a and 17 b and the axle shafts 18 a and 18 b of the front and rear wheels 4 and 8 via the propeller shaft 17. Can be plunged into an object to be excavated, for example, piled earth and sand A (shown in FIG. 6).

  A discharge portion of the working hydraulic pump 19 is connected to the arm cylinder 10, the bucket cylinder 11, the steering cylinder 13, and the like via the control valve 20. That is, the lift arm 2 is moved up and down (up and down the bucket 3), the bucket 3 is rotated (change in the direction of the bucket 3), and the work vehicle 1 is steered by the hydraulic oil discharged from the work hydraulic pump 19. I can let you.

  On the other hand, as shown in FIG. 3A, a driver's seat 41 on which a boarded operator sits is provided in the center of the cab 6. In front of the driver seat 41, an instrument panel 43 and a steering handle 60 are provided. On the instrument surface 44 formed on the instrument panel 43, various pilot lamps (parking brake lamps, etc.), a speed meter indicating the traveling speed of the work vehicle 1, a fuel gauge, and a shift indicator indicating the shift position (all shown) Information required for driving, etc. is displayed.

  A number of operation units are provided around the driver's seat 41 and the steering handle 60. Specifically, around the steering handle 60, a shift lever 61 for instructing a speed stage (for example, 1st to 4th speed shift) and a forward / reverse switching lever (not shown) are provided. The floor portion is provided with a working brake pedal 62, a traveling brake pedal 63, a traveling accelerator pedal 64 (corresponding to the first operation portion of the present application), and the like. Incidentally, the shift lever 61 is provided with a shift sensor 37 for detecting a shift position, and the accelerator pedal 64 is provided with an accelerator sensor 30 for detecting an accelerator opening.

  On the front side of the upper surface of the side console panel 42 formed on the side of the driver's seat 41, an operation lever 22a for rotating the bucket 3 in the vertical direction and an operation lever 22a for raising and lowering the bucket 3 An operation lever 22b (corresponding to the second operation unit of the present application) is provided.

  Further, around the operation levers 22a and 22b, the engine output of the work vehicle 1 is set in a plurality of modes, for example, P (power) mode (work) according to the work to be excavated with different work loads such as clayey sand and gravel. The E / P switch 38 (corresponding to the selection part of the present application) that can be selected from two types of modes such as an E (economy) mode (a mode that emphasizes fuel efficiency), and the forward operation of the work vehicle 1 An M / A switch 35 that can be switched to an auto mode or a manual mode is provided. Incidentally, for the E / P switch 38, for example, an alternate type switch as shown in FIG. 3B is used.

  Among these, the operation levers 22 a and 22 b are connected to a control valve 20 that controls the movement of the arm cylinder 10 and the bucket cylinder 11. Thereby, when the operation lever 22b is operated, the arm cylinder 10 expands and contracts according to the operation amount, and the bucket 3 is moved up and down. When the operation lever 22a is operated, the bucket cylinder 11 expands and contracts according to the operation amount so that the angle of the bucket 3 can be changed.

  For example, a controller 26 is provided behind the driver seat 41. The controller 26 includes, for example, a CPU, a ROM, a RAM, and other peripheral circuits. Various controllers necessary for controlling the work vehicle 1 and the work implement 21 are connected to the controller 26.

  That is, the controller 26 includes an arm angle sensor 27 that detects an angle of the lift arm 2 with respect to the work vehicle 1, a bucket angle sensor 28 that detects an angle of the bucket 3 with respect to the work vehicle 1, and an accelerator sensor 30 as shown in FIG. 2. The M / A switch 35, the shift sensor 37, the E / P switch 38, and the engine control unit 40 for controlling the engine 14 are connected.

  Further, the controller 26 includes a pressure sensor 24 (bottom pressure sensor) for detecting pressure applied to the piston base side of the cylinder in the arm cylinder 10, a pressure sensor 25 (rod pressure sensor) for detecting pressure applied to the opposite piston rod side, A vehicle speed sensor 31 for detecting the vehicle speed of the work vehicle 1, an input side rotation sensor 32 for detecting the rotation speed on the input side of the torque converter 15, an output side rotation sensor 33 for detecting the rotation speed on the output side of the torque converter 15, A pressure sensor 34 (work machine pressure sensor) for detecting the discharge pressure of the hydraulic pump 19, a solenoid control unit 39 for controlling the solenoid valve 16 a for shifting the transmission 16, and the like are also connected.

In addition, the controller 26 is set with a function of setting the engine output according to the work load or controlling the automatic shift with the output.
That is, for example, the controller 26 determines the P mode as shown in FIG. 4 as the point of the maximum rotation speed of the engine 14 (there is no limitation on the maximum rotation speed), and sets the E mode to the maximum engine rotation speed than the P mode. An engine output performance map (based on the engine output torque and the rotational speed) set on the low low speed side is set.

  With this setting, when the operator selects the P mode by recognizing the magnitude of the work load, the pressure oil is supplied to the work implement 21 and the work vehicle 1 under the engine output without the upper limit of the maximum rotation speed of the engine 14. Done. When the E mode is selected, the pressure oil is supplied to the work implement 21 and the work vehicle 1 under the engine output with the maximum rotation speed of the engine 14 suppressed to the low speed side.

  In addition to this, the controller 26 sets a target engine rotational speed in accordance with the depression amount (operation amount) of the accelerator pedal 64 and controls the rotational speed of the engine 14 to the target engine rotational speed, and the torque converter 15. Speed ratio (output-side rotational speed / input-side rotational speed) is calculated, and when the obtained speed ratio becomes larger than the reference speed ratio, the solenoid control unit 39 is instructed to shift up, and the speed ratio is the reference speed ratio. When it becomes smaller, a function for instructing the solenoid control unit 39 to shift down, a characteristic map of each speed stage (1st to 4th speed) as shown in FIG. 5 (based on the accelerator opening and the vehicle speed), etc. are set. ing.

  With this setting, when the M / A switch 35 is selected to the auto mode, the automatic shift control is performed in accordance with the speed ratio of the torque converter 15 up to the speed stage (1st speed stage to 4th speed stage) detected by the shift sensor 37. To be done. That is, automatic shift is performed with the speed stage selected by the shift lever 61 as an upper limit.

  Incidentally, the input torque B1 (shown in FIG. 4) input to the transmission 16 depends on the speed ratio of the torque converter 15 (rotational speed on the output side / rotational speed on the input side) and the absorption torque of the working hydraulic pump 19. Therefore, when the speed ratio of the torque converter 15 is increased, it is increased as B0 in FIG. 4, and when the speed ratio of the torque converter 15 is decreased, it is decreased as B2 in FIG. Therefore, as shown in the characteristics of FIG. 5, the P mode has a higher driving force than the E mode, and the maximum vehicle speed at each speed stage is higher by the amount of the higher engine rotation speed. When the manual mode is selected with the M / A switch 35, the gear is shifted at an arbitrary speed stage by manual operation of the shift lever 61.

  Here, with reference to FIG. 6, the excavation work for excavating the piled earth and sand A by the wheel loader will be described. First, each lever operation (arm operation lever 22 a and bucket operation lever 22 b by the boarded operator). ), The arm cylinder 10 and the bucket cylinder 11 are driven, the loading / unloading port at the tip of the bucket 3 is directed forward, and the entire bucket is disposed directly above the ground [FIG. 6 (a)].

  Thereafter, from this posture, for example, P mode (selection by the work to be excavated), auto mode (automatic shift mode) is selected, the accelerator pedal 64 is stepped on, and the work vehicle 1 is moved forward with the work to be excavated. Move to some earth and sand A. With this advance, the tip of the bucket 3 enters the earth and sand A as shown in FIGS. 6A and 6B, and the earth and sand A is loaded into the bucket 3.

  When loading is completed as shown in FIG. 6B, the arm cylinder 10 and the bucket cylinder 11 are driven by lever operation (operation levers 22a and 22b), and the direction of the bucket 3 as shown in FIG. The bucket 3 is lifted while changing to an upward posture. The excavation work of earth and sand A is performed by a series of operations so far. Then, earth and sand A is discharged. For example, the earth and sand are carried to a truck bed (not shown), and the bucket 3 is operated to face downward above the truck, so that the earth A in the bucket 3 is discharged to the truck bed.

At this time, the skilled operator is able to proceed with excavation work with an operation that provides good fuel efficiency and operation efficiency based on empirical rules, etc., but when it is an unskilled operator, due to lack of proficiency, Excavation work is easy to proceed with operations with poor fuel efficiency and work efficiency.
For this reason, for example, a portion of the operator's cab 6 that is easy for the operator to watch, for example, a portion adjacent to the instrument surface 44 of the instrument panel 43 as shown in FIG. A device 45 is provided.

The display device 45 includes a display 46 having, for example, a rectangular display surface 46a on the front surface of the instrument panel 43, and a control unit 47 that displays information indicating whether the excavation work is good or bad on the display surface 46a. .
Here, the force for performing the excavation work corresponds to the driving force generated by the forward operation (operation by the accelerator pedal 64) of the work vehicle 1 as shown in FIG. Traction force α and the lift force β when lifting the bucket 3 loaded with the earth and sand A brought about by the operation of the lever (the arm operation lever 22a and the bucket operation lever 22b) different from the operation system. . The total force is represented by excavation force γ, which is the resultant force of traction force α and lift force β.

  Therefore, the control unit 47 is provided with a function of displaying the quality of the traction force α and the lift force β during excavation work in real time and displaying the use status of the excavation capacity of the bucket 3 in cooperation with the controller 26. It has been. FIG. 8 shows the structure of each part of the control unit 47 constituting these functions, and FIG. 9 shows a display form displayed on the display surface 46 a by the control of the control unit 47.

  Here, as shown in FIG. 8, the control unit 47 includes a traction force calculation unit 48, a lift force calculation unit 50, an excavation work start / end determination unit 52, an excavation force calculation unit 54, a loaded weight calculation unit 55, and a comparison calculation unit. 56, a score calculation unit 57, a target value setting unit 58, and the like. The function of each unit of the control unit 47 will be described below.

The traction force α for performing excavation work is represented by the force with which the driving force of the engine 14 is transmitted to the front and rear wheels 4, 8. Therefore, the traction force α is calculated by using a traction force calculator 48 based on, for example, the input side rotation speed and the output side rotation speed of the torque converter 15. Specifically, the traction force α is calculated in the traction force calculation unit 48 by, for example, the speed ratio [= (output-side rotation sensor value / (input-side rotation sensor value)] of the torque converter 15 and the capacity coefficient [= (torque Converter input torque / torque converter input speed ² ) × 10 ⁶ (Nm / rpm ² )], and using the speed ratio, capacity coefficient, and input speed of torque converter 15, torque converter 15 The output torque [= torque ratio (reciprocal of speed ratio) × capacity coefficient × torque converter input speed ² )] is calculated, and the calculated output torque of the torque converter 15 is added to the reduction ratio of the transmission 16 and the reduction ratio of the axle ( 17a, 17b) and divided by the radii of the front and rear wheels 4, 8. More specifically, since the torque ratio and the capacity coefficient have a certain relationship with the speed ratio when the size of the torque converter 15 is determined, the output torque of the torque converter 15 can be calculated from the speed ratio.

  The lift force β for performing excavation work is calculated based on the pressure oil applied to the arm cylinder 10 that drives the lift arm 2. Therefore, in calculating the lift force β, the lift force calculation unit 50 uses the hydraulic pressure applied to the arm cylinder 10 (the bottom pressure output from the pressure sensor 24) when the bucket 3 is lifted, and the lift arm 2 that is displaced by the same hydraulic pressure. Of the angle (output of the arm angle sensor 27).

The excavation force γ is calculated by the excavation force calculation unit 54 (corresponding to the first excavation force calculation unit of the present application) by calculating the resultant force of the calculated instantaneous traction force α and the calculated instantaneous lift force β. It is obtained by.
The excavation work start / end determination unit 52 is one element that determines the efficiency of excavation work of the bucket 3. The bottom pressure of the arm cylinder 10 output from the pressure sensor 24 is used to determine the start and end of the excavation work.

  That is, the bottom pressure (pressure detected by the pressure sensor 24) of the arm cylinder 10 during excavation work is low when the work vehicle 1 moves forward toward the earth and sand A, and increases sharply and drastically when the excavation work starts. This high situation continues throughout the entire excavation section. When excavation work is finished, it shows a behavior that drops sharply. For example, when the pressure P is set as one reference value, the bottom pressure of the arm cylinder 10 has a behavior that is lower than the reference value P over the entire section in the forward process and significantly higher than the reference value P in excavation work. Since the bottom pressure is higher than the reference value P in the first half of the earth removal work and lower than the reference value P after that, there is a difference in behavior from the excavation work. The time for the forward process until reaching the earth and sand A is usually about several seconds (for example, 5 seconds).

  Therefore, the excavation work start / end determination unit 52 detects the time when the bottom pressure of the arm cylinder 10 is lower than the reference value P for a predetermined time and then increases and exceeds the reference value P as the start time of the excavation work. Thereafter, the time when the reference value P is lowered is detected as the end point of the excavation work, and the operation start to end is determined.

  Further, the excavation force calculation unit 54 has a function of calculating an average excavation force that is an average of excavation forces during the excavation work from the start time to the end time of the excavation work, and uses the average excavation force as the latest excavation work (current time). The value from this value to the past excavation work at a predetermined point in time is accumulated, and the cumulative average excavation force value divided by the number of excavation works (sampling number) is calculated.

  The loaded weight calculation unit 55 (corresponding to the loaded weight detection unit of the present application) calculates (detects) the actual loaded weight of the earth and sand A (the object to be excavated) loaded in the bucket 3. The actual loading weight is calculated, for example, from the rotational moment applied to the arm cylinder 10 in the loaded state (the moment with the pin 10a supporting the base side of the arm cylinder 10 as a fulcrum), and this is used as the arm of the lift arm 2 The total load weight is obtained by correcting the angle, and is obtained by subtracting the empty weight from the total load weight.

  Specifically, the load weight calculation unit 55 calculates, for example, from the force applied to the rod side of the arm cylinder 10 (calculated from the bottom pressure or pressure receiving area) from the force applied to the bottom side of the arm cylinder 10 (calculated from the rod pressure or pressure receiving area). ) To obtain a rotational force, and from a preset correction map (not shown), a correction coefficient corresponding to the arm angle of the lift arm 2 shown in the drawing (for correcting different rotational force depending on the arm angle) is obtained. To get the total load weight. The actual loaded weight is detected by subtracting the weight (bucket 3 and lift arm 2) in a preset empty state from the total loaded weight. Of course, in order to increase the accuracy, a calculation considering the center of gravity of the loading amount may be added.

The target value setting unit 58 has a function of storing various target values. Here, the value of the target traction force, the value of the target lift force, and the value of the target excavation force used for performing the optimum excavation work are set. Specifically, based on the work mode selected by the E / P switch 38 (excavation work modes with different excavation loads), two types of target traction force values for each mode, here for E mode and P mode, and target lift Force value and target excavation force value are set. The target value setting unit 58 is also set with a target excavation force value per unit weight of the loaded weight, which is determined in advance according to the loading specification of the bucket 3, which is the excavation capability of the bucket 3.
The comparison calculation unit 56 (corresponding to the first comparison unit of the present application) is a target traction force value, a target lift force value, a target excavation force value, and a traction force α calculated by the traction force calculation unit 48 input from the target value setting unit 58. It has a function of comparing the lift force β calculated by the lift force calculation unit 50 and the excavation force γ calculated by the excavation force calculation unit 54. Specifically, the comparison calculation unit 56 obtains the ratio of the traction force α, the lift force β, and the digging force γ with respect to the target traction force value, the target lift force value, and the target digging force value.

  The score calculation unit 57 (corresponding to the second excavation force calculation unit of the present application) is calculated (detected) by the average excavation force value output from the excavation force calculation unit 54, here the accumulated average excavation force value, and the load weight calculation unit 55. And a function of calculating an actual excavation force value per unit weight (accumulated average excavation force value per unit weight) based on the accumulated average value of the actual loaded weight value of the bucket 3. Further, the target digging force value per unit weight of the loaded weight obtained by the target value setting unit 58 is input to the score calculation unit 57, and from this, the score calculation unit 57 (the second comparison unit of the present application) is input. Equivalent) further has a function of comparing the target excavation force value per unit weight with the actual excavation force value per unit weight. Specifically, the score calculation unit 57 divides the target excavation force value per unit weight by the actual excavation force value per unit weight, thereby obtaining the target excavation force value per unit weight and the actual excavation force value per unit weight. The ratio (score) is calculated.

  Each ratio of the above traction force α (instantaneous), lift force β (instantaneous), excavation force γ (instantaneous) and target traction force value, target lift force value, target excavation force value, and the above target digging force value per unit weight and unit A signal such as a ratio (score) with the actual excavation force value per weight is input to the display 46.

  As shown in FIG. 9, the display surface 46 a of the display 46 is divided into two sections, for example, the display area of the display surface 46 a, and the upper display area 69 displays whether the excavation efficiency of the bucket 3 is good or bad. The part to be used (here, the score monitor). The lower display area 70 is a portion (here, an excavation force monitor) that displays the quality of the traction force α, the lift force β, and the excavation force γ (the resultant force of the traction force and the lift force) during excavation work in real time.

  The display form will be described. In the lower display area 70, a picture imitating a side view of the entire wheel loader is displayed on the right side of the display area 70 in order to make it easy to understand the work status of the wheel loader. On the left side of the display area 70, a horizontal bar display type indicator 72 extending in the horizontal direction from the vicinity of the tip of the bucket of the hole loader shown in the picture, and a vertical bar display type indicator 73 extending in the vertical direction from the base of the indicator 72. In addition, an oblique bar display type indicator 74 extending obliquely upward from the vicinity of the base ends of these indicators 72 and 73 is provided (both correspond to the first display portion of the present application).

  By the indicators 72 to 74 arranged corresponding to the direction of the force at the time of excavation work, the traction force α shown as an instantaneous magnitude as a lateral force or an instantaneous magnitude as a vertical force in real time. The lift force β shown and the excavation force γ showing the resultant force in an instantaneous magnitude can be displayed.

  The indicators 72 to 74 are each composed of a plurality of blocks, for example, six blocks. The display unit 46 sets the target traction force value, the target lift force value, and the target excavation force value in the same mode as the upper limit of the indicators 72 to 74 according to the selection of the P mode or the E mode, respectively, and the contrast calculation unit 56. Traction force α (instantaneous), lift force β (instantaneous), and excavation force γ (instantaneous) target traction force value, target lift force value, and ratio of target digging force value calculated in step 1 ) Function is set. Further, the display unit 46 has a function of displaying the upper value and the lower value in different colors across the bar display value near the limit of the target value. Are displayed in different colors (for example, orange, green, etc.) with a value of about 80% of each indicator 72 to 74 as a boundary.

  From these displays, the calculated traction force, lift force, and excavation force are displayed in comparison with the target traction force value, the target lift force value, and the target excavation force value that prompt the optimum work. That is, in real time, the operator is informed of the status of traction force, lift force, and excavation force in the current excavation work.

  The upper display area 69 is provided with a bar-shaped indicator 76 (corresponding to the second display section of the present application) extending so as to occupy the entire left and right direction of the display area 69. The indicator 76 displays the comparison result between the target excavation force value per unit weight calculated by the score calculation unit 57 and the actual excavation force value per unit weight as a bar. Specifically, the display unit 46 has the entire indicator 76 (100%) corresponding to the target excavation force value per unit weight, and the target excavation force value per unit weight calculated by the score calculation unit 57. And a function for displaying the ratio (score) between the actual digging force value per unit weight in a bar shape.

From this display, the actual digging force per unit weight is also displayed in comparison with the target digging force value per unit weight, so that the use condition (good or bad) of the digging ability of the bucket 3 can be understood. For example, since the actual digging force per unit weight increases when the loading weight of earth and sand A is small, the ratio (score) between the target digging force value per unit weight and the actual digging force value per unit weight is an indicator 76. In this case, it can be determined that the utilization of the excavation capacity of the bucket 3 is not very good. On the other hand, as the actual excavation force value per unit weight approaches the target excavation force value per unit weight, that is, as the display of the indicator 76 is closer to the whole (100%), it can be determined that the excavation capability of the bucket 3 is better used. .
In addition, the display area 69 is provided with a reset operation unit 69a for resetting the accumulated starting point of the average excavating force so that the accumulated starting point of the average excavating force can be changed at any time.

  The indicator 46 is connected to a notification device, such as a sound generator 46b, for notifying when the actual traction force or the actual lift force exceeds the target traction force or the target lift force. It also has a structure for notifying the operator that the lift force is excessive.

  According to the display device 45 configured in this manner, during excavation work with the wheel loader, the bucket 3 is moved to the earth and sand A (object to be excavated) by the accelerator operation (advance traveling) shown in FIGS. 6 (a) and 6 (b). The traction force α at the time of the entry work is displayed as a bar by the indicator 72 in real time while being compared with the target traction force value.

Further, the lift force β when the bucket 3 that has been loaded with the earth and sand A is lifted by the lever operation shown in FIG. 6C is compared with the target lift force value in real time, with the display indicator 73. Is displayed as a bar. Further, the excavation force γ which is the resultant force of both is displayed as a bar by the indicator 74 while being compared with the target excavation force value.
The ratio (score) between the target excavation force value per unit weight of the earth and sand A and the actual excavation force value per unit weight indicating the loading condition of the earth and sand A is displayed as a bar.

  At this time, if the operator is a skilled person, the actual traction force, the actual lift force, and the actual excavation force are displayed on the indicators 72 and 73, respectively, as bars extending to near the upper limit (100%). The indicator 76 is also displayed as a bar extending to near the upper limit (100%).

  On the other hand, when an unskilled operator performs excavation work, a state in which the earth and sand A is not sufficiently loaded into the bucket 3 occurs due to a lack of the traction force α, or the earth and sand A is loaded due to a lack of the lift force β. There is a case where the bucket 3 is not lifted as expected (work efficiency is low).

  Here, the lack of the traction force α in the traction process (the forward movement of the work vehicle) is when the stepping operation of the accelerator pedal 64 is insufficient. Therefore, the indicator 72 includes, for example, only two blocks as shown in the black portion in FIG. Shows tractive force with a small display that lights up (extreme example). That is, the display of the indicator 72 informs the operator that there is a point to be corrected in the towing operation, and tells the operator how much the traction force is lower than the target traction force, and prompts the operator to perform an operation that is optimal in the traction process. .

In response to this, the operator may increase the depression of the accelerator pedal 64. Then, the driving force (traction force) for advancing the bucket 3 as indicated by the hatched portion in FIG. 9 increases (correction of the traction operation), and the bucket 3 can be pulled with the optimum traction force α. That is, it is possible to optimally load the earth and sand A into the bucket 3.
Incidentally, when the actual traction force exceeds the target traction force, an alarm sound indicating the same state is output from the sound generator 46b. As a result, the operator is prompted to suppress the stepping operation of the accelerator pedal 64.

  In addition, the lack of lift force β in the lift process (lifting the bucket) following the traction process is different from the traction operation described above when the lever operation (operation lever 22b) is insufficient. The lift force is shown in a small display such that only two blocks are lit as shown in the black part of FIG. 10 (extreme example). This indicator 73 informs the operator how much the target lift force is lower than the target lift force while notifying the operator that there is a point to be corrected in the lift operation.

That is, as in the case of the traction operation, the operator is urged to perform an optimal operation in the lift process (the lift of the bucket 3). In response to this, the operator only has to increase the amount of operation of the operation lever 22a as indicated by the hatched portion in FIG. 10 (correction of the lift operation), and thereby the bucket 3 can be lifted with the optimum lift force. It becomes possible. That is, the excavation work of earth and sand A can be advanced optimally.
Incidentally, when the actual lift force exceeds the target lift force, an alarm sound indicating the same state is output from the sound generator 46b as in the towing process, and prompts the operator to suppress the lever operation.
As a result, when the loading weight of the earth and sand A is small, the indicator 76 is displayed with a bar shorter than the whole, and when the excavation work of the earth and sand A is optimal and the loading weight of the earth and sand A is sufficient, the indicator 76 is displayed. Is displayed as a bar extending to near the upper limit (100%).

  In this way, during excavation work that makes full use of different operation systems, the indicators 72 and 73 respectively allow the operator to make an operation of the bucket 3 entering the earth and sand A (object to be excavated) in real time, and the subsequent earth and sand A. By visually recognizing (recognizing) the quality of the operation of lifting the bucket 3 loaded with the load, the optimum operation can be promoted in each stage of work (work vehicle advance, bucket lift).

In addition, the target traction force value, the target, and the accelerator pedal 64 (first operation unit), the arm operation lever 22a, and the bucket operation lever 22b (both are the second operation unit) are associated with each operation state (operation amount). Since the actual traction force value and lift force value with respect to the lift force value can be visually confirmed, the operator is encouraged to improve the fuel consumption and to operate with good work efficiency at each stage of work (vehicle advance, work implement lift). it can.
Therefore, excavation work by the bucket 3 can be performed by an unskilled operator by an operation equivalent to that of the skilled worker, that is, an operation with good fuel efficiency and high work efficiency. That is, it is possible to prompt an unfamiliar operator to perform an optimum operation that brings about an efficient excavation work.

  In addition, since the digging force γ, which is the resultant force of the traction force α and the lift force β, is displayed on the indicator 74, the operator can also visually check the degree of change in the magnitude of the digging force and easily understand the state of the digging work. In addition, since the indicators 72 to 74 change the target traction force value, the target lift force value, and the target excavation force value in cooperation with the E / P switch 38, they are optimal for excavation work of any work load. The operation can be prompted to the operator.

  In particular, according to the comparison result of the actual excavation force per unit weight and the target excavation force value per unit weight displayed by the indicator 76, the operator can reach the point of efficiency such as whether or not the excavation capacity of the bucket 3 is fully utilized. Can also be recognized. Thereby, it is possible to prompt the operator to perform an optimal operation from a comprehensive point of view, and the excavation work can be advanced comprehensively and efficiently.

  Moreover, since the average excavation force value specialized only for the excavation work from the entry of the bucket 3 to the lift is used for the calculation of the actual excavation force value per unit weight in the score calculation unit 57, it is specialized for the excavation work. Under the easy-to-read display, the efficiency of excavation work can be recognized. In addition, the average excavation force value is accumulated from the latest excavation work to the value of the past excavation work times, and the cumulative average excavation force value divided by the number of excavation work times is used. In this way, the efficiency of excavation work can be recognized. In particular, the reset operation unit 69a resets the cumulative starting point, so that the operator's personal excavation efficiency information can also be obtained, which is useful for improving the operator's own skills.

FIG. 11 shows a second embodiment of the present invention.
This embodiment is a modification of the first embodiment, and instead of displaying the actual traction force and the actual lift force together with the actual excavation force as in the first embodiment, the target traction force and the target lift force are individually displayed. It is made to display while contrasting.

  That is, the display area of the display surface 46a is divided into four sections, top, bottom, left, and right, and the right display area 81 is used as a part that displays the quality of the traction force α and the lift force β during excavation work in real time. Further, the upper left display area 82 is a portion for displaying the average excavation force of the bucket 3 (here, the average excavation force monitor), and the left middle display area 83 is the efficiency of excavation work as in the first embodiment. A part for displaying the history from the latest actual excavation force value to the past (predetermined number of) actual excavation force values in the display area 84 on the lower left side (Here, excavation force history).

  Specifically, in the display area 81 on the right side, for example, a picture simulating a side view of the bucket 3, a picture simulating a tire (front and rear wheels), a vertical indicator 91 for traction force extending in the vertical direction, A vertical indicator 92 is provided so that traction force (instant) and lift force (instant) can be displayed in real time.

  The upper left display area 82 is provided with a digital display area 94 for displaying the calculated average excavation force of the bucket 3 in a digital display, and the middle left display area 83 is the same as in the first embodiment. The bar-shaped indicator 95 is provided so that the ratio (score) between the target excavation force value per unit weight and the actual excavation force value per unit weight can be displayed. In the lower left display area 84, there is provided a display switch 96 for switching to a history display mode for displaying the accumulated average excavation force value. Incidentally, FIG. 12 shows an example of a history of excavation force values displayed on the display surface 46a when switching to the history display mode (vertical bar display).

Even in such a display form, the same effects as in the first embodiment can be obtained. In particular, when the average excavation force value and the history of excavation force values are displayed together, points for improving the excavation work are more likely to appear, so that the excavation work can be carried out more efficiently.
However, in FIG. 11, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the bar display is used for the display of the instantaneous traction force, the instantaneous lift force and the excavation force, and the display of the comparison result of the excavation force. Display may be performed, and the display form is not limited.
Of course, the present invention may be applied to other construction machines instead of the wheel loader.

1 work vehicle 1x car body 2 lift arm 3 bucket (work machine)
4,8 Front wheel, rear wheel (wheel)
10 Arm cylinder (hydraulic actuator)
11 Bucket cylinder (hydraulic actuator)
22a, 22b Operation lever (second operation part)
38 E / P switch (selection part)
45 display device 48 tractive force calculation unit 50 lift force calculation unit 54 excavation force calculation unit (first excavation force calculation unit)
55 Load weight calculator (load weight detector)
56 Contrast calculation section (first contrast section)
57 Score calculation unit (second excavation force calculation unit, second comparison unit)
64 Accelerator pedal (first operation part)
72, 73 Indicator (1st display part)
76 Indicator (second display)

Claims (5)

A vehicle body having wheels, a work machine provided at a front portion of the vehicle body, a first operation part provided on the vehicle body for operating a traction force of the vehicle body, and a second operation part for commanding and operating the operation of the work machine A display device for a construction machine that performs excavation work by operating the first operation unit and the second operation unit,
A traction force calculator for calculating the traction force in the excavation work;
A lift force calculation unit for calculating a lift force of the work machine in the excavation work;
A first comparison unit that compares the calculated traction force value and lift force value with a preset target traction force value and target lift force value for excavation work, respectively;
A display device for a construction machine, comprising: a first display unit that displays a comparison result of the first comparison unit. A selection unit provided so that the upper limit of the traction force and the lift force can be selected according to different work loads in advance;
The display device for a construction machine according to claim 1, wherein the target traction force value and the target lift force value are set based on selection by the selection unit. A first excavation force calculator that calculates an excavation force represented by the resultant force of both the calculated traction force value and the calculated lift force value;
A loading weight detection unit for detecting the loading weight of the work to be excavated loaded on the working machine;
A second excavation force calculator that calculates excavation force per unit weight based on the calculated excavation force and the detected loading weight;
A second comparison unit for comparing the calculated excavation force value per unit weight with a target excavation force value per unit weight set in advance according to the loading specifications of the work implement;
The construction machine display device according to claim 1, further comprising: a second display unit that displays a comparison result of the second comparison unit. The second excavation force calculation unit further calculates an average value of excavation force per unit weight from the start of excavation work in which an object to be excavated is loaded onto the work implement to the end of excavation work to finish lifting the work implement. Calculate
The said 2nd contrast part contrasts the average value of the digging force per unit weight from the start of the said digging operation to the completion | finish of a digging operation with the target digging force value per said unit weight. A display device for a construction machine as described in 1.   The average value of the digging force per unit weight used in the second contrast unit is the cumulative value from the value at the time of the latest excavation work to the number of past excavation work, and the number of excavation work so far. The display device for a construction machine according to claim 4, wherein a cumulative average excavation force value per unit weight divided by.

Images