JP2008133657A - Excavating/loading machine and automatic excavating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress impact when a bucket runs into sediment while sufficiently increasing the output of an engine. <P>SOLUTION: A wheel loader 1 comprises a laser range sensor 10. A laser beam 11 is emitted from the laser range sensor 10 diagonally downward, and the wheel loader 1 measures the distance L1 to an emitting position P1 on the ground while traveling forward. When the wheel loader 1 approaches the sediment 9 to be excavated and the measured distance L2 reaches a specified distance Ls, the rotational speed of the engine (unshown) of the wheel loader 1 is increased by an instruction, and the tilt amount of the engine at which the rotational speed is transmitted to rear wheels 6b is controlled. Therefore, the rise of the forward traveling speed of the wheel loader 1 due to an increase in the rotational speed of the engine can be suppressed. Consequently, the impact caused when the bucket 2 runs into the sediment 9 can be relieved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a machine, such as a wheel loader, that travels forward and backward to perform excavation / loading work on an object to be excavated, and more particularly to the excavation / loading machine and an automatic excavation method.

  FIG. 15 is an explanatory view showing main parts of a wheel loader as an example of an excavation / loading machine, where 1 is a wheel loader, 2 is a bucket, 3 is an arm, 4 is a bucket cylinder, 5 is an arm cylinder, 6a is a front wheel, 6b is a rear wheel, 7 is a transmission, 8 is an operation room, and 9 is earth and sand.

  In FIG. 1A, the wheel loader 1 is provided with an arm 3 having a bucket 2 attached to the front end on the front wheel 6a side, and by operating a lever provided in the operation chamber 8, the engine ( The rotation of an unillustrated) is controlled, and the driving force thereby is transmitted to the front wheel 6a and the rear wheel 6b via the transmission 7, so that the front wheel 6a and the rear wheel 6b rotate and the wheel loader 1 travels. Further, a hydraulic pump (not shown) is driven by the rotation of the engine, and the arm cylinder 5 and the bucket cylinder 4 are driven by the hydraulic pressure to operate the arm 3 and the bucket 2.

  FIG. 15B shows a state in which the wheel loader 1 excavates the earth and sand 9, and the bucket 2 penetrates into the earth and sand 9 by causing the wheel loader 1 to travel forward with the bucket 2 being lowered to the ground. Thereby, excavation work of the earth and sand 9 is started.

  2. Description of the Related Art Conventionally, like a wheel loader, a technique is known in which buckets and arms are controlled while traveling, and an operation of excavating and loading objects such as earth and sand is automated.

  As an example, sensors such as a vehicle speed sensor, bucket angle sensor, boom angle sensor, and bucket load sensor are provided. When starting excavation work, the work machine is advanced with the engine at full power and the boom and bucket are lowered. The bucket is pushed horizontally into the excavated soil in the lowered state, the traction rate or the fall rate is obtained based on the detection value of each sensor, and the traction rate or the fall rate follows a predetermined set value. As described above, a technique has been proposed in which excavation work is performed by automatically controlling buckets and booms so that the arm can be lifted and buckets can be tilted at the same time, so that the amount of excavated soil becomes uniform ( For example, see Patent Document 1).

As another example, in order to prevent a tire slip due to a sudden change in load when the wheel loader is moved forward to penetrate the bucket into the earth and sand, when the bucket penetrates into the earth and sand, the horizontal resistance Rh of the bucket is obtained, A technique has also been proposed in which when the horizontal resistance Rh is greater than a predetermined value, the throttle control unit is controlled to reduce the engine speed and the vehicle speed of the wheel loader (see, for example, Patent Document 2). ).
Japanese Unexamined Patent Publication No. 62-185828 JP-A-1-111927

  Excavation and loading machines that excavate while controlling the bucket and arm while traveling, such as a wheel loader, have the required engine output during mere movement and excavation to the position where excavation starts. Different. At the time of excavation work, such work is performed by the traveling of the excavation / loading machine and the bucket arm operation, so that a larger engine output is required as compared with the case of simple traveling travel. For this reason, as described in Patent Documents 1 and 2, when starting excavation work, the output of the engine is increased to advance the work machine at a high speed, and the bucket is thrust into (penetrated into) the sand to be excavated horizontally. ing.

  By the way, there is a delay time from when the engine output is increased to when the engine output actually increases. Therefore, when excavation is performed, the engine output is increased when the bucket enters the earth and sand. Therefore, when the excavation / loading machine is traveling toward the excavated earth and sand, an operation for increasing the output of the engine is performed.

  However, in this way, if the engine output is increased during traveling before the bucket is pushed horizontally into the soil to be excavated, the traveling speed of the excavating / loading machine will increase, and in a state of moving at high speed The bucket will thrust into the earth and sand. For this reason, the impact applied to the excavation / loading machine and its operator when the bucket thrusts into the earth and sand becomes large, and the change in the detection output of the sensor when the bucket thrusts into the earth and sand is used as a trigger for starting the excavation operation However, there is a problem that this large impact causes the sensor to be erroneously detected.

  An object of the present invention is to provide an excavation / loading machine and an automatic excavation method capable of solving such a problem and suppressing an impact when a bucket thrusts into earth and sand while sufficiently increasing an output of an engine. It is in.

  In order to achieve the above object, an excavation / loading machine according to the present invention includes a working mechanism including a bucket and an arm and a traveling mechanism for traveling forward and backward, and a power source for the working mechanism and the traveling mechanism. A first excavator / loader machine for excavating and loading an object to be excavated and detecting a positional relationship with the object to be excavated; The second means for detecting that the predetermined position at a predetermined distance from the object to be excavated is reached during forward traveling, and the second means has reached the predetermined position based on the positional relationship detected by And a third means for reducing the driving force from the engine to the wheels is provided to increase the rotational speed of the wheel as the rotational speed of the engine increases. Even after passing the specified position, It is characterized in that the running speed before passing through the position that it has configured to be able to forward travel in approximately equal speed.

  Further, the present invention is characterized in that the first means is a laser distance sensor, and the second means is means for comparing and determining a distance measured by the laser distance sensor and a predetermined set value. To do.

  In the present invention, the first means includes a stereo camera and a processing means for processing the output of the stereo camera and measuring the distance to the specified position, and the second means detects the rotation of the wheel. The wheel rotation sensor for measuring the travel distance, and the means for comparing and determining the travel distance measured by the wheel rotation sensor and the distance to the specified position measured by the processing means.

  In the present invention, the first means includes a stereo camera and first processing means for processing the output of the stereo camera to measure the distance to the specified position, and the second means is a GPS sensor. Second processing means for calculating the position coordinates of the specified position by calculating the detection output of the GPS sensor and the distance to the specified position measured by the first processing means, and the current position by the detection output of the GPS sensor And the third processing means for comparing and determining the position coordinates of the specified position obtained by the second processing means.

  In order to achieve the above object, an automatic excavation method for an object to be excavated according to the present invention measures the positional relationship of an excavation / loading machine that is traveling forward with respect to the object to be excavated, and the excavation / loading machine has the object to be excavated. The excavation / loading machine performs control to increase the engine speed of the excavation / loading machine when a predetermined position of a predetermined distance from the object is reached, and the excavation / loading machine accompanies the increase in the engine speed. The excavation / loading machine travels at the traveling speed before reaching the specified position after reaching the specified position.

  According to the present invention, even if the rotational speed of the engine is increased immediately before excavation operation, the forward traveling at a substantially specified speed can be continued without changing the forward traveling speed of the excavation / loading machine. It is possible to suppress the impact when the pierce enters the object to be excavated and to prevent erroneous detection due to the impact of each sensor.

Embodiments of the present invention will be described below with reference to the drawings.
The following embodiment is an example of a wheel loader, but the present invention is not limited to this, and is applicable to any excavation / loading machine that performs excavation work by traveling. Not too long.

  FIG. 1 is an explanatory view showing a first embodiment of an excavation / loading machine and an automatic excavation method according to the present invention, wherein 10 is a laser distance sensor, 11 is a laser beam, and a portion corresponding to FIG. The same reference numerals are assigned and duplicate descriptions are omitted.

In FIG. 1A, a laser distance sensor 10 is provided on the wheel loader 1, for example, on the roof of the operation room 8. The radar distance sensor 10 has a laser beam emission port directed obliquely downward, so that the laser beam 11 from a laser source (not shown) is directed to a position P ₁ at a predetermined distance in front of the wheel loader 1. The reflected laser beam 11 from the position (irradiation position) P ₁ is received, and the distance L to the irradiation position (reflection position) P ₁ of the laser beam emitted from the laser distance sensor 10 is measured. . If the irradiation position P ₁ is on the flat ground while the wheel loader 1 is moving, the distance L measured by the laser distance sensor 10 is substantially constant as L ₁ .

FIG. 1B shows a state in which the wheel loader 1 is approaching the earth and sand 9 to be excavated, and when the wheel loader 1 travels at a specified speed (hereinafter referred to as a specified speed) V ₀ and enters such a state. The laser light 11 emitted from the laser distance sensor 10 starts to be applied to the earth and sand 9. When the laser beam 11 starts irradiating the earth and sand 9, the distance L from the laser distance sensor 10 measured at that time to the irradiation position P ₂ on the earth and sand 9 becomes L ₂ (<L ₁ ). Here, the position P ₂ at which the laser beam 11 starts to be applied to the earth and sand 9 is hereinafter referred to as the starting position of the earth and sand 9.

Thus, the wheel loader 1 automatically detects that the bucket 2 has reached the position of the distance L ₂ from the earth and sand 9 to be excavated, that is, has approached the earth and sand 9 at an interval of the distance L _2. Is done. The value of the distance L ₂ is set in advance as a distance setting value L _S, by detecting the distance L of the laser distance sensor 10 is compared with the distance setting value L _S, the wheel loader 1 approaches the sediment 9 Is detected.

Sediment The laser distance defined position the tip of the bucket 2 has reached when the detection distance L becomes a distance set value L _S between the sensor 10 and the start position P ₂ of the sediment (which is excavated to the start position P ₂ of 9, when the distance setting value Ds value of the distance D between the provision that the front position) P ₃ and the start position P ₂ of the sediment sediment 9 is excavated (hereinafter, this distance D is referred to as a set distance Ds), and when the wheel loader 1 continues to drive the set distance Ds at the specified speed V ₀ without changing the running speed V, a command to increase the engine output (rotation speed) is given. A sufficient distance setting value Ds that can be set to a predetermined high-speed rotation speed while traveling the set distance Ds is determined. That is, in the first embodiment, when the tip of the bucket 2 reaches the specified forward position P ₃ of the earth and sand 9, by detecting that the measurement distance L of the laser distance sensor 10 has become the distance set value L _S. An engine output (rotation speed) increase command is automatically issued, and the engine output (rotation speed) increases to a specified value while the wheel loader 1 travels the set distance Ds at the specified speed V _0. To be able to.

Further, as the engine output (the number of revolutions) increases, the transmission amount of the tilting amount driving force to the front wheels 6a and the rear wheels 6b via the transmission 7 due to the engine output is reduced, and the moving speed V of the wheel loader 1 is specified. The speed V ₀ is maintained.

FIG. 2 shows the relationship between the change in the engine speed n _E (FIG. 2A) and the change in the tilt amount driving force transmission rate η to the front wheels 6a and the rear wheels 6b (FIG. 2B). FIG.

In the state until the wheel loader 1 approaches the earth and sand 9 to be excavated as shown in FIG. 1A, the engine speed n _E is 1500 rpm, for example, as shown in FIG. As shown in FIG. 2B, the rolling drive force transmission rate η is 100%, and it is assumed that the wheel loader 1 is traveling forward at the specified speed V ₀ .

Thereafter, as shown in FIG. 1B, when the wheel loader 1 approaches the earth and sand 9 and the tip of the bucket 2 reaches the specified forward position P ₃ of the earth and sand 9 (time t ₁ ), as shown in FIG. There is a command to increase the engine speed, and the engine speed n _E increases. As the engine speed n _E increases, the tilt amount driving force transmission rate η decreases so that the forward travel speed V of the wheel loader 1 is maintained at the specified speed V ₀ .

Then, before the wheel loader 1 travels forward from the time t ₁ by the set distance Ds, as shown in FIG. 2A, when the engine speed n _E reaches a prescribed value, for example, 2000 rpm (time t ₂ ). The tilt amount driving force transmission rate η maintains the forward travel speed V of the wheel loader 1 at the set speed V ₀ , for example, 30%. While this state is maintained, the wheel loader 1 travels further forward toward the sand 9 (and therefore travels forward at the set speed V ₀ ), the wheel loader 1 travels forward by the set distance Ds, and the tip of the bucket 2 is moved to the earth and sand. 9 the start position P and ₂ to reach the (time t _3), is to start drilling operation sediment 9 from this point, with this, as shown in FIG. 2 (b), the tilting amount driving force transmission factor η For example, the driving force of the wheel loader 1 is increased to 50% to increase the efficiency of excavation work. Note that the wheel loader 1 travels forward by the set distance Ds by detecting the penetration of the bucket 2 into the earth and sand 9 by using a detection output of a pressure sensor described later that detects an external pressure applied to the bucket 2. It is to be detected.

  FIG. 3 is a flowchart showing the above operation.

In this figure, when the wheel loader 1 is traveling forward at the specified speed V ₀ toward the earth and sand 9 to be excavated, as described with reference to FIG. 1A, the distance between the laser distance sensor 10 and the reflection position on the ground is shown. L is constantly measured (step 100). As shown in FIG. 1A, the detection distance L of the laser distance sensor 10 is the distance set value L until the tip of the bucket 2 reaches the specified forward position P ₃ of the set distance Ds from the start position P _{2 of the} earth and sand 9. _In this case (“No” in step 101), the operations in steps 100 and 101 are repeated.

When the detection distance L of the laser distance sensor 10 is equal to or less than the distance setting value L _S (“Yes” in step 211), the tip of the bucket 2 is set from the start position P _{2 of the} earth and sand 9 as shown in FIG. the distance in a state where prescribed reached forward position P ₃ of the Ds, by which, together with the command speed up of the engine is issued at the wheel loader 1, for suppressing the increase in the running speed of the wheel loader 1 due to the rotation speed-up of the engine A solenoid valve control command is also issued (step 102). As a result, the engine speed increases, but the wheel loader 1 still travels forward at the specified speed V ₀ .

  When the electromagnetic valve control command is issued, the wheel loader 1 further measures the external pressure applied to the bucket cylinder 4 and the arm cylinder 5 (step 103) and compares it with a preset pressure set value (step 104). Before the bucket 2 penetrates into the earth and sand 9, the measured external pressure value is smaller than the pressure set value (“No” in Step 104), and the external pressure applied to the bucket cylinder 4 and the arm cylinder 5 is measured as it is. (Step 103) When the measured external pressure value becomes equal to or higher than the set pressure value (“Yes” in Step 104), the bucket 2 starts to penetrate the earth and sand 9 and the excavation process is executed (Step 105).

Thus, in the first embodiment, even if the engine output (rotation speed) is increased before the bucket 2 penetrates the earth and sand 9, the forward travel speed V of the wheel loader 1 is set to the engine output (rotation speed). ) Is maintained at the specified speed V ₀ before the speed is increased, the speed when the bucket 2 penetrates the earth and sand 9 can be kept low, and the impact when the bucket 2 penetrates the earth and sand 9 can be kept small. Can do.

  FIG. 4 is a block diagram showing a specific example of the control system of the wheel loader 1 shown in FIG. 1, wherein 10 is a laser distance sensor, 12 is an arm rotation sensor, 13 is a bucket rotation sensor, 14 is a steering rotation sensor, 15 is a pressure sensor, 16 is an engine rotation sensor, 17 is a car body acceleration sensor, 18 is a car body tilt sensor, 20 is an automatic operation control controller, 20a is a drilling object recognition process, 20b is a travel process, 20c is a drilling process, and 20d is Earth release position recognition processing, 20e is earth removal processing, 20f is excavation / travel switching processing, 20g is automatic operation sequence processing, 30 is a travel tilt amount control solenoid valve, 31 is a bucket control solenoid valve, and 32 is an arm control solenoid valve , 33 is a steering control solenoid valve, 34 is a forward / update / neutral switching solenoid valve, 35 is a stepping motor for throttle control, and 36 is a brake. A control unit.

  In the figure, the wheel loader 1 shows the state of each part such as an arm rotation sensor 12, a bucket rotation sensor 13, a steering rotation sensor 14, an engine rotation sensor 16, a vehicle body acceleration sensor 17, and a vehicle body inclination sensor 18. A sensor for detecting, a pressure sensor 15 for detecting an external pressure applied to the laser distance sensor 10 and the bucket 2 arm 3 are provided. The detection outputs of these sensors are supplied to the automatic operation controller 20. Here, the pressure sensor 15 detects an external pressure applied to the bucket 2 and the arm 3, detects a change in the detected pressure, and detects that the bucket 2 has entered the earth and sand 9. The engine speed sensor 16 detects the engine speed, and when the engine speed is instructed to increase, the engine speed becomes the specified speed as described with reference to FIG. Determine that.

The automatic operation control controller 20 is activated by a predetermined operation in the operation room 8 (FIG. 1) of the wheel loader 1 and uses a detection output of each of the sensors 10 and 12 to 18 to perform a series for excavation of the earth and sand 9. The automatic operation sequence process 20g that defines the operation procedure is started. By the automatic operation sequence process 20g, the sediment 9 is measured by the excavation object recognition process 20a that measures the distance to the sediment 9 that is the excavation object by using the detection output of the laser distance sensor 10 until the sediment 9 is excavated. provisions detecting the forward position P ₃ (FIG. 1 (b)), provisions If this provision forward position P ₃ is detected, along with commanding the rotational speed up of the engine, the traveling speed of the wheel loader 1 to travel processing 20b The excavation / travel switching process 20f for maintaining the speed V ₀ is automatically performed to control the throttle control spindle motor 35 and the travel tilt amount control electromagnetic valve 30, and the detection output of the pressure sensor 15 is used. When the bucket 2 of the wheel loader 1 is detected to reach the start position P ₂ of the soil 9, the drilling process 20c and Hodo position recognition process 20d, Hodo process 20e is performed Is, the bucket control solenoid valve 31, the arm control solenoid valve 32, the steering control solenoid valve 33, solenoid valves, such as forward, updating and neutral switching solenoid valve 34 is controlled, the working operation such as drilling is performed.

  FIG. 5 is a block configuration diagram showing a main part of one specific example of the automatic operation controller 20 in FIG. 4 together with necessary sensors and solenoid valves, 21 and 22 are input processing units, 23 is a comparator, Reference numeral 24 is a set value storage memory, 25 is an automatic travel sequence processing unit, 26 is an engine speed increase processing unit, and 27 is an excavation processing unit. The same reference numerals are given to the parts corresponding to those in FIG. To do.

  In the figure, pressure sensors 15a to 16d for detecting external pressure applied to the bucket cylinder 4 and the arm cylinder 5 of the wheel loader 1 are provided. These pressure sensors 15a to 15d correspond to the pressure sensor 15 in FIG.

  When the wheel loader 1 is turned on for excavation work and the operation room 8 is operated for automatic operation, the automatic operation control controller 20 is activated, and the engine speed increase processing unit 26, excavation processing unit 27, The automatic running sequence processing unit 25 that performs the switching is activated, and the engine speed increasing processing unit 26 is put into an operating state. Further, the laser distance sensor 10 is also activated, and the detection output is supplied to the input processing unit 21. In the input processing unit 21, the detection output of the laser distance sensor 10 is processed, and the distance L from the laser distance sensor 10 shown in FIG. 1 to the reflection point of the laser beam 11 is calculated. This calculated distance (detection distance) L is supplied to the comparator 23.

On the other hand, in the set value storage memory 24, various values such as a distance set value L _S (FIG. 1 (b)) for the detected distance L and a pressure set value F _S for the pressure F obtained from the detected pressures of the pressure sensors 15a to 15d. Set values are set, and the power is turned on as described above, and these set values are read from the set value storage memory 24 and set in the comparator 23.

In the comparator 23, when the detection distance L is supplied from the input processing unit 21, the detection distance L is compared with the distance setting value L _S. The wheel loader 1 moves forward at the specified speed V ₀ when a travel start command is issued by operating the lever in the operation chamber 8, but the tip of the bucket 2 is at the specified forward position P ₃ (FIG. 1 (b)). Before it reaches,
Detection distance L> Distance setting value L _S
(This state is a state in which the processing of steps 100 and 101 in FIG. 3 is repeated). However, when the wheel loader 1 continues traveling forward and the tip of the bucket 2 reaches the specified forward position P ₃ ,
Detection distance L = Distance setting value L _S
(The state of “Yes” in step 101 in FIG. 3), the comparator 23 causes the engine speed increase processing unit 26 to compare the detection distance L with the distance setting value L _S based on the comparison result. It gives a command I _1. As a result, the engine speed increase processing unit 26 sends an engine speed increase command _IE to the throttle control spindle motor 35, and suppresses an increase in the traveling speed of the wheel loader 1 accompanying the increase of the engine speed. The electromagnetic valve control signal C _V is supplied to the traveling tilt amount control electromagnetic valve 30. As a result, the spindle motor 35 for throttle control increases the rotational speed n _{E of the} engine (not shown) (FIG. 2A), and at the same time, the travel tilt amount control electromagnetic valve 30 is controlled to control the wheel loader 1. The amount of tilting (driving force electric power ratio to the rear wheel 6b) η (FIG. 2B) is reduced, and the forward traveling speed of the wheel loader 1 is maintained at the specified speed V ₀ .

On the other hand, when an operation for automatic operation is performed in the operation room 8, the detection output of the pressure sensors 15a to 15d is processed by the input processing unit 22 such as averaging, and the pressure F applied to the bucket 2 is measured. 23. When the comparator 23 gives the command I ₁ to the engine speed increase processing unit 26 based on the above comparison result indicating that the detected distance L is equal to the distance setting value L _S , next, the input processing unit 22 Is compared with the pressure set value F _S fetched from the set value storage memory 23. Until the packet 2 penetrates the earth and sand 9 described in FIG.
Pressure F <Pressure setting value F _S
In this state, the measurement of the pressure F and the comparison with the pressure set value F _S are repeated (this state is the state in which the processes of steps 103 and 104 in FIG. 3 are repeated), but the bucket 2 of the wheel loader 1 Reaches the start position P ₂ of the earth and sand 9 and the bucket 2 starts to penetrate into the earth and sand 9,
Pressure F = Pressure setting value F _S
(The state of “Yes” in step 104 in FIG. 3), the comparator 23 sends the excavation operation start command I ₂ to the excavation processing unit 27. As a result, the excavation processing operation starts (step 105 in FIG. 3). At the same time, the comparator 23 gives a command I ₃ to the engine speed increase / solenoid valve control processing unit 26. As a result, the engine speed increase / solenoid valve control processing unit 26 supplies the traveling tilt amount control electromagnetic valve 30 with the electromagnetic valve control signal C _V for increasing the traveling speed of the wheel loader 1 to a predetermined set value. The traveling tilt amount control solenoid valve 30 increases the tilt amount (driving force transmission rate) η by this solenoid valve control signal C _V as shown by the operation from time t ₃ in FIG. Thus, the driving force of the wheel loader 1 is increased to increase the efficiency of excavation work.

FIG. 6 is a circuit diagram showing a specific example of a hydraulic circuit provided in the wheel loader 1 in FIG. 1, wherein 5a and 5b are arm cylinders, 6a ₁ and 6a ₂ are front wheels, and 6b ₁ and 6b ₂ are rear wheels. , 38 is a traveling mechanism section, 39 is a working mechanism section, 40 is an engine, 40a is a throttle, 41 is a variable displacement hydraulic pump for traveling, 42 is a charge pump, 43 is a hydraulic pump for working equipment, and 44a and 44b are main lines. , 45 is a hydraulic motor, 46 is a cross overload relief valve, 47 is a throttle, 48 is a tilting cylinder, 48a and 48b are cylinder chambers, 48c is a piston, 49a and 49b are conduits, 50 is an on-off valve, 50a and 50b Is a pipe, 50c is a spring, 51 is a pipe, 52 is a tank, 53a and 53b are steering cylinders, and 54 is a throttle. I will omit the description.

In this figure, in this hydraulic circuit, the front wheel 6a ₁ and 6a ₂ or the rear wheels 6b ₁ and 6b ₂ are driven to drive the wheel loader 1 forward and backward, the bucket cylinder 4 and the arm. A working mechanism unit 39 for performing excavation work by operating the bucket 2 and the arm 3 by driving the cylinders 5a and 5b and the steering cylinders 53a and 53b, and the traveling mechanism unit 38 and the working mechanism are provided. One engine 40 is also used as a drive source for the unit 39.

  The throttle 40a of the engine 40 is driven by the rotation of the throttle control stepping motor 35, and the engine 40 rotates. The rotational speed of the engine 40 is higher as the rotational speed of the throttle control stepping motor 35 is higher. Due to the rotation of the engine 40, the variable displacement hydraulic pump 41 for traveling, the charge pump 42, and the hydraulic pump 43 for work implement rotate.

  The variable displacement hydraulic pump 41 for travel is supplied to the hydraulic motor 45 with a tilt amount (push-off capacity) and a flow rate of hydraulic oil according to the tilt amount according to the state of the piston 48c of the tilt cylinder 48. The wheel loader 1 travels when the direction is determined and the rotational force of the hydraulic motor 45 is transmitted to the rear wheels 6b1 and 6b2 via the transmission 7. When the piston 48c is in the neutral position in the tilt cylinder 48, the tilt amount of the variable displacement hydraulic pump 41 for travel is zero and the discharge amount of pressure oil is zero. For this reason, since the hydraulic motor 45 is not supplied with pressure oil, it does not rotate and the wheel loader 1 is in a stopped state. Further, when the piston 48c is displaced toward the cylinder chamber 48a by the tilt cylinder 48, a tilt amount corresponding to the displacement amount is set in the travel variable displacement hydraulic pump 41, and the travel variable displacement hydraulic pump 41 Pressure oil having a flow rate corresponding to the tilting amount is discharged in one direction, that is, the main pipeline 44a. As a result, the hydraulic motor 45 is supplied with pressure oil from the main line 44a side and rotates forward, and the wheel loader 1 moves forward. The forward travel speed in this case depends on the flow rate of the pressure oil in the main pipeline 44a, and accordingly, the amount of tilt set in the travel variable displacement hydraulic pump 41. On the contrary, when the piston 48c is displaced toward the cylinder chamber 48b by the tilt cylinder 48, a reverse displacement amount corresponding to the displacement amount is set in the travel variable displacement hydraulic pump 41, and the travel variable displacement hydraulic pressure is set. Pressure oil with a flow rate corresponding to this tilting amount is discharged from the pump 41 to the other direction, that is, the main pipe 44b. Thereby, the hydraulic motor 45 is supplied with pressure oil from the main pipeline 44b side and rotates in the reverse direction, and the wheel loader 1 moves backward. In this case, the reverse travel speed also corresponds to the flow rate of the pressure oil in the main pipe 44b, and accordingly, the reverse tilt amount set in the variable displacement hydraulic pump 41 for travel. The hydraulic motor 45 rotates at a rotational speed corresponding to the hydraulic pressure corresponding to the flow rate of the pressure oil supplied from the main pipeline 44a or 44b, and the maximum pressure is set by the cloy overload relief valve 46. Therefore, the maximum rotational speed of the hydraulic motor 45 is limited, and the maximum traveling speed of the wheel loader 1 is also limited.

  On the one hand, the pressure oil discharged from the charge pump 42 is directly supplied to the forward / reverse / neutral switching electromagnetic valve 34, and on the other hand, it is supplied to the forward / reverse / neutral switching electromagnetic valve 34 via the throttle 47. When the forward / reverse / neutral switching solenoid valve 34 is in the neutral position shown in the figure, the pressure oil from the throttle 47 is supplied to the cylinder chamber 48a and the cylinder chamber 48b of the tilt cylinder 48 through the pipes 49a and 49b. The As a result, the piston 48c of the tilt cylinder 48 is set to the neutral position, the tilt amount of the variable displacement hydraulic pump 41 for travel is set to zero, the hydraulic motor 45 is set to the stop state, and the wheel loader 1 is set to the stop state. It becomes.

  When the forward / reverse / neutral switching electromagnetic valve 34 is switched to the side (A) shown in the figure, the pressure oil directly from the charge pump 42 is supplied to the cylinder chamber 48a of the tilting cylinder 48 via the pipe 49a. Is supplied to the cylinder chamber 48b of the tilting cylinder 48 through the pipe 49b. As a result, the piston 48c of the tilting cylinder 48 is displaced toward the side where the cylinder chamber 48a is narrowed by the differential pressure before and after the throttle 47, and the traveling variable displacement hydraulic pump 41 is tilted in the positive direction according to the amount of displacement. The amount is set. Accordingly, the hydraulic oil having a flow rate corresponding to the tilting amount is discharged from the variable displacement hydraulic pump 41 for traveling to the main pipeline 44a and supplied to the hydraulic motor 45, so that the wheel loader 1 travels forward.

  Further, when the forward / reverse / neutral switching solenoid valve 34 is switched to the (B) side shown in the drawing, the direct pressure oil is supplied from the charge pump 42 to the cylinder chamber 48b of the tilting cylinder 48 via the pipe line 49b. The pressure oil from 47 is supplied to the cylinder chamber 48a of the tilting cylinder 48 through the pipe line 49a. As a result, the piston 48c of the tilting cylinder 48 is displaced to the side that narrows the cylinder chamber 48b by the amount of the differential pressure before and after the throttle 47, and the traveling variable displacement hydraulic pump 41 is tilted in the reverse direction according to the amount of displacement. The amount is set. Accordingly, the hydraulic oil having a flow rate corresponding to the tilting amount is discharged from the variable displacement hydraulic pump 41 for traveling to the main pipe 44b and supplied to the hydraulic motor 45, and the wheel loader 1 travels backward.

  In this way, by controlling the forward / reverse / neutral switching solenoid valve 34, the wheel loader 1 can be stopped, forward travel, and reverse travel can be switched.

  From the work implement hydraulic pump 43, pressure oil is discharged to the work implement pipe 51 and supplied to the bucket control solenoid valve 31, the arm control solenoid valve 32, and the steering control solenoid valve 33. When excavation work is not performed and the electromagnetic valves 31 to 33 are in the neutral position, the pressure oil supplied from the work machine pipe 51 is discharged to the tank 52.

  When excavation work is performed, at least one of the bucket control solenoid valve 31, the arm control solenoid valve 32, and the steering control solenoid valve 33 is operated, and the bucket 2 is operated by supplying pressure oil to the bucket cylinder 4. When the pressure oil is supplied to the arm cylinders 5a and 5b, the arm 3 operates, and when the pressure oil is supplied to the steering cylinders 53a and 53b, the direction of the arm 3, the bucket 2, and the operation chamber 8 is changed. It is done.

  Here, an on-off valve 50 is provided between the pipe lines 49a and 49b via the pipe lines 50a and 50b. In the on-off valve 50, a spring 50c is provided, and a pressure (traveling load pressure) Pt in the main pipe 44a and a pressure (working machine load pressure) Pf in the working machine pipe 51 are applied. The open / close valve 50 switches between the open state and the closed state according to the magnitude relationship between the sum (Pt + Pf) of these pressures and the pressure Pr of the spring 50c, and the hydraulic motor according to the load variation during excavation work. The rotational speed of 45 is controlled, and the forward and reverse traveling speeds of the wheel loader are controlled.

In such a hydraulic circuit configuration, when the forward / reverse / neutral switching solenoid valve 34 is switched to the (A) side, the forward displacement amount is set in the variable displacement hydraulic pump 41 for traveling, and the hydraulic pressure When the motor 45 rotates forward and the wheel loader 1 is traveling forward at the specified speed V ₀ , the throttle is controlled by the engine speed increase command _IE from the engine speed increase / solenoid valve control processing unit 26 (FIG. 5). When the rotational speed of the control stepping motor 35 increases and the rotational speed of the engine 40 increases as shown in FIG. 2A, the variable displacement hydraulic pump 41 for traveling, the charge pump 42, and the hydraulic pump 43 for work implements. The number of revolutions increases. The flow rate of the pressure oil discharged from the charge pump 42 increases as the rotational speed increases, and the hydraulic pressure difference before and after the throttle 47 also increases. As a result, the state of the piston 48c in the tilt cylinder 48 also changes, and the tilt amount in the variable displacement hydraulic pump 41 for travel also increases. Due to the increase in the rotational speed of the engine 40 and the increase in the tilt amount of the variable displacement hydraulic pump 41 for travel, the discharge amount of the pressure oil from the travel variable displacement hydraulic pump 41 to the main pipe 44a is significantly increased. Then, the rotational speed of the hydraulic motor 45 is increased, and the forward traveling speed of the wheel loader 1 is greatly increased from the specified speed V ₀ .

In this embodiment, in order to suppress the increase in the forward traveling speed of the wheel loader 1, the traveling tilt amount control electromagnetic valve 30 and the throttle 54 are provided between the pipe lines 49a and 49b, and the engine speed increase / electromagnetic valve is increased. The traveling tilt amount control electromagnetic valve 30 is controlled by the electromagnetic valve control signal C _V from the control processing unit 26 (FIG. 5).

That is, in the state before the tip of the bucket 2 of the wheel loader 1 reaches the specified forward position P ₃ of the earth and sand 9 to be excavated (FIG. 1 (a)), the traveling tilt amount control solenoid valve 30 is closed as shown in the figure. in a state, the piston 48c of the tilting cylinder 8 is in a state corresponding to the differential pressure across the diaphragm 47, the tilting amount of the variable displacement hydraulic pump 41 for traveling, the forward wheel loader 1 is at a specified speed V ₀ It is set to run.

Thereafter, the tip of the bucket 2 of the wheel loader 1 reaches the specified forward position P ₃ of the earth and sand 9 to be excavated, and the solenoid valve control signal C _V is supplied from the engine speed increase / solenoid valve control processing unit 26 (FIG. 5). Then, the travel tilting amount control electromagnetic valve 30 is opened, and the pipes 49 a and 49 b communicate with each other via the throttle 54. As a result, the hydraulic pressure difference between the pipe line 49a and the pipe line 49b becomes a pressure difference before and after the throttle 54, whereby the state of the piston 48c in the tilting cylinder 48 changes, and the variable capacity for traveling is changed. The amount of tilt in the hydraulic pump 41 changes.

Therefore, the amount of tilting of the variable displacement hydraulic pump 41 for traveling that has changed in this way is that of the wheel loader 1 with respect to the designated rotational speed (for example, 2000 rpm in FIG. The aperture amount of the aperture 54 is set so that the forward travel speed is the tilt amount with the specified speed V ₀ (for example, 30% in FIG. 2B).

Incidentally, as shown in FIG. 2 (b), the bucket 2 is slightly increased tilting amount when t ₃ when starting the excavation and penetrate the soil 9 (e.g., 50% in FIG. 2 (b)) for For example, the throttle amount of the throttle 54 is variable, and the electromagnetic valve control signal C _V is output from the engine speed increase / solenoid valve control processing unit 26 based on the command I ₃ from the comparator 23 (FIG. 5). Then, the aperture amount of the aperture 54 is increased. Alternatively, in addition to the travel tilt amount control electromagnetic valve 30 and the throttle 54, a throttle having a larger throttle amount than the throttle 54 and a travel tilt amount control electromagnetic valve are provided between the pipe lines 49a and 49b. When there is a command I ₃ from the comparator 23 (FIG. 5), the travel tilt amount control solenoid valve is opened (at this time, the travel tilt amount control solenoid valve 30 is closed). May be activated. As a result, the hydraulic pressure difference between the pipes 49a and 49b increases, and the amount of tilt in the travel variable displacement hydraulic pump 41 increases to, for example, 50% as shown in FIG.

As described above, in the first embodiment, even if the rotational speed of the engine 40 is increased immediately before the excavation operation, the forward travel at substantially the specified speed V ₀ without changing the forward travel speed of the wheel loader 1. Can be suppressed, the impact when the bucket 2 penetrates the earth and sand 9 can be suppressed, and erroneous detection due to the impact of each sensor can be prevented.

  FIG. 7 is an explanatory view showing a second embodiment of the excavation / loading machine and automatic excavation method according to the present invention. 55 is a stereo camera, and parts corresponding to the previous drawings are given the same reference numerals. A duplicate description is omitted.

  In the figure, for example, on the roof of the operation room 8 of the wheel loader 1, a stereo camera 55 composed of two right and left CCD cameras is provided. Using the stereo camera 55, a so-called stereo method is used to reach the subject. The distance Dx is measured. In the stereo method, the same subject is photographed by two cameras, the amount of deviation of the subject image on the photographing screen of each camera is obtained, and the distance to the subject is obtained from the amount of deviation based on the principle of triangulation. Is.

  Therefore, in the second embodiment, by directing the wheel loader 1 in the direction of the earth and sand 9 to be excavated, the stereo camera 55 is directed in the direction of imaging the earth and sand 9 and the distance Dx to the earth and sand 9 is measured. . Thereafter, the wheel loader 1 is started to travel forward toward the earth and sand 9 and, at the same time, a distance D traveled by the wheel loader 1 is measured. The distance D is obtained by detecting the rotation speed and rotation angle of the front wheel 6a and the rear wheel 6b of the wheel loader 1 with a sensor.

When the wheel loader 1 travels forward at a distance D = Dx−Ds from the distance Dx to the specified distance Ds, the tip of the bucket 2 of the wheel loader 1 reaches the specified forward position P ₃ of the earth and sand 9 and an engine speed increase command is issued. Thereafter, the same processing operation as in the first embodiment is performed.

  In the second embodiment, as in the first embodiment, the engine speed and the amount of tilt are controlled as shown in FIG.

  FIG. 8 is a block diagram showing a specific example of the control system of the wheel loader 1 shown in FIG. 7, wherein 55 is a stereo camera shown in FIG. 7, 56 is a wheel rotation sensor, and a portion corresponding to FIG. The same reference numerals are assigned and duplicate descriptions are omitted.

  In this figure, the second embodiment is different from the control system in the first embodiment shown in FIG. 4 in that a stereo camera 55 and a wheel rotation sensor 56 are used instead of the laser distance sensor 10. It is.

In the automatic operation controller 20, first, the stereo camera 55 recognizes the sediment 9 to be excavated, searches for the distance Dx there, and calculates the distance Dx−Ds to the set forward position P ₃ of the sediment 9. Excavation object recognition processing 20a is performed. When the distance Dx−Ds is calculated, the traveling distance 20 of the wheel loader 1 is measured by the traveling process 20 b based on the forward traveling of the wheel loader 1 and the detection output of the wheel rotation sensor 56. Then, when it is detected by this distance measurement that the tip of the bucket 2 of the wheel loader 1 has reached the set forward position P ₃ of the earth and sand 9, an explanation of the engine speed increase is issued, although the explanation is omitted below. The same processing operation as in the control system shown in FIG. 4 in the first embodiment is performed.

  FIG. 9 is a flowchart showing the above operation. Note that the steps corresponding to those in FIG.

In the figure, in a state where the wheel loader 1 is stopped in the direction of the earth and sand 9 to be excavated, the earth and sand 9 is photographed and recognized by the stereo camera 55, and from the position of the tip of the bucket 2 of the wheel loader 1 to the earth and sand 9. Is measured (step 200). Then, a distance (= Dx−Ds) from the measured distance Dx and the set distance Ds to the set forward position P ₃ of the earth and sand 9 is obtained and set as a travel setting process (step 201), and the wheel loader 1 travels forward. Is started (step 202).

The distance Dx from the tip position of the bucket 2 of the wheel loader 1 to the start position P ₂ of the earth and sand 9 can be obtained by calculating the distance obtained from the output of the stereo camera 55.

The start of forward travel of the wheel loader 1, the wheel rotation sensor 26 sequentially measures the travel distance D of wheel loader 1 (step 203 and 204 "No"), between the tip of the bucket 2 has reached the set forward position P ₃ The travel distance D measured in
D ≧ Dx−Ds
(Yes in step 204), the wheel loader 1 issues a command for increasing the engine speed and a solenoid valve control command (step 102), and processing operations similar to those in steps 103 to 105 in FIG. Is done.

  FIG. 10 is a block diagram showing the essential part of one specific example of the automatic operation controller 20 in FIG. 8 together with necessary sensors, solenoid valves, etc., wherein 56a to 56d are wheel rotation sensors, and 57 is a travel distance calculation. Reference numeral 58 denotes a distance measuring unit between excavation objects, and parts corresponding to those in FIG. 5 and FIG.

  In this figure, in this automatic driving controller 20, instead of the input processing unit 21 that processes the laser distance sensor 10 in the automatic driving controller 20 in the first embodiment shown in FIG. An excavation object distance measurement unit 58 that processes an image, and a travel distance calculation unit 57 that processes detection outputs of wheel rotation sensors 56a to 56d that detect the rotation speed and rotation angle of each front wheel and each rear wheel of the wheel loader 1. The other configuration is the same as that of the automatic operation controller 20 shown in FIG.

The wheel loader 1 is turned on for excavation work, the operation is performed in the operation room 8, the wheel loader 1 is directed to the earth and sand 9 to be excavated, and the panning and tilting operations of the stereo camera 55 are performed. When directed to the earth and sand 9 and an operation for automatic driving is performed, the captured images from the two CCD cameras of the stereo camera 55 are sent to the distance measuring unit 58 between the excavation objects, and the captured images are processed. However, the imaging direction of these CCD cameras is adjusted, and the distance Dx to the earth and sand 9 is measured (step 200 in FIG. 9). When this measured distance Dx is obtained, the excavation object distance measuring unit 58 activates the automatic traveling sequence processing unit 25 and at the same time the planned traveling distance (= Dx−) until the tip of the bucket 2 reaches the set forward position P _3. Ds) is obtained and set in the comparator 23 (step 201 in FIG. 9). The automatic traveling sequence processing unit 25 is activated and puts the engine speed up / solenoid valve control processing unit 26 into an operating state.

Then, the wheel loader 1 starts traveling forward at the specified speed V ₀ (step 202 in FIG. 9), and at the same time, the wheel rotation sensors 56a to 56d measure the rotation speed and rotation angle of the front and rear wheels, The measurement result is supplied to the travel distance calculation unit 57. The travel distance calculation unit 57 averages the wheel rotation sensors 56a to 56d and calculates the travel distance D from time to time (step 203 in FIG. 9). The travel distance D is sequentially obtained along with the forward travel of the wheel loader 1 and supplied to the comparator 23. The comparator 23 compares the travel distance D sequentially supplied from the travel distance calculation unit 57 with the planned travel distance Dx−Ds from the excavation object distance measurement unit 28 every time it is supplied (step 204 in FIG. 9). of "No"), the tip of the bucket 2 of the wheel loader 1 has reached the set forward position P ₃ of the soil 9,
D ≧ Dx−Ds
Then, the command I ₁ is sent from the comparator 23 to the engine speed increase / solenoid valve control processing unit 26 (step 102 in FIG. 9).

  The subsequent operations are the same as those in the first embodiment.

  The hydraulic circuit in the second embodiment is also the same as the hydraulic circuit shown in FIG. 6 in the first embodiment, and the description thereof is omitted.

  As described above, the second embodiment can also obtain the same effects as those of the first embodiment.

  FIG. 11 is an explanatory view showing a third embodiment of the excavation / loading machine and the automatic excavation method according to the present invention, 59 is a GPS antenna, and parts corresponding to those in FIG. Description to be omitted is omitted. In the third embodiment, a GPS (Global positioning System) is used for measuring the travel distance.

  In this figure, this third embodiment is provided with a stereo camera 55 and a GPS sensor. On the roof of the wheel loader 1, for example, the operation room 8, a stereo camera 55 and a GPS sensor described later are provided. An antenna (GPS antenna) 59 is provided. This stereo camera 55 is the same as the stereo camera 55 shown in FIG. 7 in the second embodiment.

In the third embodiment, the position coordinates (latitude and longitude) of the current position P ₄ at the tip of the bucket 2 of the wheel loader 1 are detected by the GPS sensor, and the stereo camera 55 is used to detect the position coordinates of the previous second embodiment. As described above, based on the measured distance Dx−Ds to the specified forward position P ₃ of the earth and sand 9 to be excavated, the position coordinates of the specified forward position P ₃ are calculated. After that, the wheel loader 1 is started to move forward toward the earth and sand 9 and, at the same time, the position coordinates of the tip position P ₄ of the bucket 2 are measured by the GPS sensor, and the tip position P _{4 of the} bucket 2 is determined by the GPS sensor. When it reaches the specified forward position P ₃ of the sediment 9 is detected, the engine speed up command is issued, and the same processing operation as the first embodiment described above is performed.

  In the second embodiment, as in the first embodiment, the engine speed and the amount of tilt are controlled as shown in FIG.

  12 is a block diagram showing a specific example of the control system of the wheel loader 1 shown in FIG. 11, wherein 60 is a GPS sensor, 61 is a direction sensor, and parts corresponding to those in FIG. Description to be omitted is omitted.

  In the figure, the third embodiment is different from the control system in the second embodiment shown in FIG. 8 in that a GPS sensor 60 and a direction sensor 61 are used instead of the wheel rotation sensor 56. is there.

In the automatic operation controller 20, first, the stereo camera 55 recognizes the sediment 9 to be excavated, searches for the distance Dx there, and calculates the distance Dx−Ds to the set forward position P ₃ of the sediment 9. Further, the position coordinate of the current position P ₄ at the tip of the bucket 2 is detected using the GPS sensor 60 provided with the GPS antenna 59 (FIG. 11), and the direction in which the wheel loader 1 detected by the direction sensor 61 is directed. drilling object recognition process 20a for calculating the position coordinates of the set front position P ₃ of sediment 9 using the distance Dx-Ds and the calculated (this wheel loader 1 is the direction of forward travel towards the sediment 9) is performed.

Here, the current position detected by the GPS sensor 60 represents the current position of the GPS antenna 59. By calculating the detection output of the GPS sensor 60, the tip position P of the bucket 2 of the wheel loader 1 is calculated. The position coordinates of ₄ can be obtained.

When this excavation object recognition process 20a is completed, the traveling process 20b starts the forward traveling of the wheel loader 1 to the earth and sand 9, and at the same time, the detection output of the GPS sensor 60 causes the bucket 2 of the wheel loader 1 that is traveling forward. The position coordinates of the tip position P ₄ are sequentially measured. When it is detected that the tip position P ₄ of the bucket 2 of the wheel loader 1 has reached the set forward position P ₃ of the earth and sand 9, the description will be omitted below, but an engine speed increase command is issued, Processing operations similar to those of the control system shown in FIG. 4 in the first embodiment are performed.

  FIG. 13 is a flowchart showing the above operation. Note that the steps corresponding to those in FIG.

In the figure, first, similarly to the second embodiment, in the state where the wheel loader 1 is stopped in the direction of the earth and sand 9 to be excavated, the earth and sand 9 is photographed and recognized by the stereo camera 55. The distance Dx to the earth and sand 9 is measured (step 300). Then, a distance Dx-Ds from this measurement distance Dx and set distance Ds to set forward position P ₃ of the sediment 9, based on the distance Dx-Ds, the bucket 2 detected by the GPS sensor 60 the tip of the From the position coordinates of the current position P ₄ and the direction detected by the direction sensor 61, the position coordinates of the set forward position P ₃ of the earth and sand 9 are obtained (step 301). Then, the wheel loader 1 starts to travel forward (step 302).

As the wheel loader 1 starts traveling forward, the GPS sensor 60 sequentially measures the position coordinates of the tip position P ₄ of the bucket 2 of the wheel loader 1 (“No” in steps 303 and 304), and the tip of the bucket 2 is set to the set forward position. It reached the P _3,
When the position coordinate of P ₄ = the position coordinate of P ₃ (“Yes” in step 304), the wheel loader 1 issues a command for increasing the engine speed and a solenoid valve control command (step 102). Processing operations similar to those in steps 103 to 105 are performed.

  FIG. 14 is a block diagram showing the principal part of one specific example of the automatic operation controller 20 in FIG. 12 together with necessary sensors, solenoid valves, etc., 62 and 63 are an input processing part, and 64 is a comparison operation part. Therefore, the same reference numerals are given to the portions corresponding to those in FIGS.

In this figure, in this automatic driving controller 20, instead of the travel distance calculation unit 57 that processes the detection outputs of the wheel rotation sensors 56a to 56d in the automatic driving controller 20 in the second embodiment shown in FIG. An input processing unit 62 that processes the detection output of the GPS sensor 60 and an input processing unit 62 that processes the detection output of the direction sensor 61 are provided. obtains the position coordinates of the position P _3, and the comparison operation unit 64 is provided for comparison operation and the position coordinates of the tip position P ₄ of the bucket 2 based on the detection output of the GPS sensor 60, other configuration in FIG. 10 This is the same as the automatic operation controller 20 shown.

The wheel loader 1 is turned on for excavation work, the operation is performed in the operation room 8, the wheel loader 1 is directed to the earth and sand 9 to be excavated, and the panning and tilting operations of the stereo camera 55 are performed. When an operation for automatic driving is performed in the direction of the earth and sand 9, the captured images from the two CCD cameras of the stereo camera 55 are sent to the distance measurement unit 58 between the excavation objects. The distance measurement unit 58 between the excavation objects adjusts the imaging direction of these CCD cameras while processing the captured images, measures the distance Dx to the earth and sand 9, and sets the earth and sand 9 from the tip position P ₄ of the bucket 2. A distance Dx−Ds to the front position P3 is calculated and supplied to the comparison calculation unit 64 (step 300 in FIG. 13).

Further, the detection output of the GPS sensor 60 is supplied to the input processing unit, the position coordinates of the tip position P ₄ of the bucket 2 of the wheel loader 1 are calculated, supplied to the comparison calculation unit 64 as the current position information P, and the direction sensor The detected output 61 is supplied to the input processing unit 63, and the direction in which the wheel loader 1 moves forward is obtained and supplied to the comparison calculation unit 64 as the direction information A. The comparison operation unit 64, the current position information A current position coordinates of the tip position P ₄ bucket 2 by the position coordinates in the direction of the distance Dx-Ds by the azimuth information A is calculated and the position coordinates sediment 9 is held as the position coordinate of the set forward position P ₃ (step 301 in FIG. 13).

When the position coordinates of the set forward position P ₃ are obtained in this way, the excavation target distance measuring unit 58 activates the automatic travel sequence processing unit 25. Thereby, the automatic travel sequence processing unit 25 puts the engine speed up / solenoid valve control processing unit 26 into an operating state.

Then, the wheel loader 1 starts traveling forward at the specified speed V ₀ (step 302 in FIG. 13), and at the same time, the GPS sensor 60 supplies the detection results to the input processing unit 63 in sequence. The position coordinates P representing the current position are sequentially supplied to the comparison calculation unit 64 (step 303 in FIG. 13). The comparison calculation unit 64 sequentially compares the position coordinates of the set forward position P ₃ of the earth and sand 9 in which the position information P is held (step 304 in FIG. 13).
When the position coordinate of P ₄ = the position coordinate of P ₃ , it is determined that the tip position P 4 of the bucket 2 has reached the set forward position P ₃ of the earth and sand 9 (“Yes” in step 304 in FIG. 13), and a comparison operation is performed. The command I ₁ is sent from the unit 64 to the engine speed increase / solenoid valve control processing unit 26 (step 102 in FIG. 13).

Subsequent operations are the same as those in the first and second embodiments. Note that step 304 in FIG. 13 may be set to (| P ₄ −P ₃ | <ΔP) in consideration of the GPS error and the automatic control error. Here, ΔP is a set value in consideration of GPS measurement error and automatic control error.

  The hydraulic circuit in the third embodiment is also the same as the hydraulic circuit shown in FIG. 6 in the first embodiment, and a description thereof is omitted.

  As described above, the third embodiment can obtain the same effects as those of the first and second embodiments.

It is explanatory drawing which shows 1st Embodiment of the excavation / loading machine and automatic excavation method by this invention. It is a figure which shows the relationship between the change of the rotation speed of the engine in 1st Embodiment shown in FIG. 1, and the inclination amount (driving force transmission factor) to a rear wheel. It is a flowchart which shows one specific example of operation | movement until excavation in 1st Embodiment shown in FIG. 1 starts. It is a block diagram which shows one specific example of the control system of the wheel loader shown in FIG. It is a block diagram which shows the principal part of one specific example of the automatic driving | operation control controller in FIG. It is a circuit diagram which shows one specific example of the hydraulic circuit provided in the wheel loader 1 in FIG. It is explanatory drawing which shows 2nd Embodiment of the excavation and loading machine by this invention, and an automatic excavation method. It is a block diagram which shows one specific example of the control system of the wheel loader shown in FIG. It is a flowchart which shows one specific example of operation | movement until excavation in 2nd Embodiment shown in FIG. 7 starts. It is a block block diagram which shows the principal part of one specific example of the automatic operation control controller in FIG. 8 with a required sensor, a solenoid valve, etc. FIG. 11 is an explanatory view showing a third embodiment of the excavation / loading machine and the automatic excavation method according to the present invention. It is a block diagram which shows one specific example of the control system of the wheel loader shown in FIG. It is a figure which shows one specific example of the customer delivery information for every phase. It is a block block diagram which shows the principal part of one specific example of the automatic operation control controller in FIG. 12 with a required sensor, a solenoid valve, etc. It is explanatory drawing which shows the principal part of the wheel loader as an example of a digging / loading machine.

Explanation of symbols

1 wheel loader 2 Bucket 3 arm 4 a bucket cylinder 5, 5a, 5b arm cylinder 6a, 6a _1, 6a ₂ front wheels 6b, 6b _1, after 6b ₂ wheel 7 Transmission 8 operating chamber 9 Sediment 10 laser distance sensor 11 laser beam 12 arm rotation Sensor 13 Bucket rotation sensor 14 Steering rotation sensor 15, 15a-15d Pressure sensor 16 Engine rotation sensor 17 Car body acceleration sensor 18 Car body tilt sensor 20 Automatic operation control controller 20a Drilling object recognition process 20b Traveling process 20c Excavation process 20d Excavation position recognition Processing 20e Excavation processing 20f Excavation / travel switching processing 20g Automatic operation sequence processing 21, 22 Input processing unit 23 Comparator 24 Setting value storage memory 25 Automatic travel sequence processing unit 26 Engine speed increase / solenoid valve control processing Section 27 Excavation processing section 30 Traveling tilt amount control solenoid valve 31 Bucket control solenoid valve 32 Arm control solenoid valve 33 Steering control solenoid valve 34 Forward / update / neutral switching solenoid valve 35 Throttle control stepping motor 36 Brake control section 38 Traveling mechanism 39 Working mechanism 40 Engine 40a Throttle 41 Traveling variable displacement hydraulic pump 42 Charge pump 43 Working machine hydraulic pump 44a, 44b Main line 45 Hydraulic motor 46 Cross overload relief valve 47 Restriction 48 Tilt cylinder 48a, 48b Cylinder Chamber 48c Piston 49a, 49b Pipe line 50 On-off valve 50a, 50b Pipe line 50c Spring 51 Pipe line 52 Tank 53a, 53b Steering cylinder 54 Aperture 55 Stereo camera 56, 56a-56d Wheel rotation sensor 57 Travel distance calculation unit 5 Drilling object distance measuring unit 59 GPS antenna 60 GPS sensor 61 azimuth sensor 62, 63 input processing unit 64 comparing unit

Claims (5)

A working mechanism including a bucket and an arm and a traveling mechanism for traveling forward and backward, and a power source for the working mechanism and the traveling mechanism is shared by a single engine, and An excavation and loading machine that performs loading work,
A first means for detecting a positional relationship between the excavation object;
Based on the positional relationship detected by the first means, a second means for detecting that a predetermined position of a predetermined distance from the excavation object has been reached during forward traveling;
When the second means detects that the specified position has been reached, a control for increasing the rotational speed of the engine and a third means for reducing the driving force from the engine to the wheels are provided, An increase in the rotational speed of the wheel accompanying an increase in the rotational speed of the engine is suppressed, and the forward traveling can be performed at a traveling speed substantially equal to the traveling speed before passing through the specified position even after passing through the specified position. Excavation and loading machine characterized by that. In claim 1,
The first means is a laser distance sensor,
The excavation / loading machine is characterized in that the second means is means for comparing and determining a distance measured by the laser distance sensor and a predetermined set value. In claim 1,
The first means includes
A stereo camera,
Processing means for processing the output of the stereo camera and measuring the distance to the specified position,
The second means includes
A wheel rotation sensor that detects the rotation of the wheel and measures the travel distance;
An excavation / loading machine comprising: a means for comparing and determining a travel distance measured by the wheel rotation sensor and a distance to the specified position measured by the processing means. In claim 1,
The first means includes
A stereo camera,
First processing means for processing the output of the stereo camera and measuring the distance to the specified position,
The second means includes
GPS (Global positioning System) sensor,
Second processing means for calculating the position coordinates of the specified position by calculating the detection output of the GPS sensor and the distance to the specified position measured by the first processing means;
Excavation and product comprising: third processing means for comparing and comparing the position coordinates of the current position based on the detection output of the GPS sensor and the position coordinates of the specified position obtained by the second processing means Included machine. In an automatic excavation method of an object to be excavated by an excavation / loading machine,
Measure the positional relationship of the excavation / loading machine while traveling forward with respect to the excavation object,
When the excavation / loading machine reaches a specified position at a predetermined distance from the object to be excavated, the excavation / loading machine is controlled to increase the engine speed, and the engine speed is increased. Control to suppress an increase in the forward traveling speed of the excavation / loading machine accompanying the rise of
An automatic excavation method for an excavation / loading machine, wherein the excavation / loading machine travels at a traveling speed after reaching the specified position but before reaching the specified position.

Images