JP4741521B2 - Front control device of hydraulic excavator - Google Patents

Description

  The present invention relates to a front control device for a hydraulic excavator that controls a front work machine in accordance with a set work area.

  As this type of front control device, a work area having a desired depth is manually set, a deceleration vector is calculated based on the speed vector at the bucket tip, and the boom is controlled according to the deceleration vector to An apparatus which limits the depth is known (for example, see Patent Document 1).

JP 2002-167794 A

  However, in the apparatus described in Patent Document 1, the body may be jacked up by the excavation reaction force, and the working posture becomes unstable.

The present invention relates to a multi-joint type front working machine having a vehicle body having a traveling body and a revolving body that can pivot with respect to the traveling body, and a boom, an arm, and a bucket that are attached to the vehicle body and that can pivot in the vertical direction. A hydraulic actuator that drives the front work machine, an operation member that inputs a drive command for the front work machine, a hydraulic control valve that controls a flow of drive pressure oil to the hydraulic actuator according to an operation of the operation member, and traveling A turning detection means for detecting a turning position of the turning body with respect to the body, a position detection means for detecting an excavation position by the front work machine, and an excavation position detected by the position detection means in a setting work area in the depth direction of the front work machine Jack for detecting jack-up of a vehicle body in a front control device of a hydraulic excavator provided with limiting means for limiting the drive of a hydraulic control valve so as not to exceed And-up detecting means, when the jack-up is detected by the jack-up detecting means, and a jack-up suppressing unit configured to increase the limit amount with the restriction means so as to suppress the jack-up, jack-up suppressing unit, turning detection The degree of increase of the restriction amount by the restriction means is changed according to the turning position detected by the means .
As jack-up suppression means, when jack-up is detected, correction for shifting the set work area upward can be performed.
It is preferable to reset the correction of the setting work area when the jack up detection is not detected by the jack-up detection means after performing the correction to shift the setting work area upward.
An inclination angle detecting means for detecting an inclination angle in the front-rear direction of the vehicle body, and a determining means for determining that the jack-up is detected when a rate of increase in the inclination angle detected by the inclination angle detecting means exceeds a predetermined value. It may have.

  According to the present invention, the drive of the hydraulic control valve is limited so that the excavation position does not exceed the set work area in the depth direction of the front work machine, and the hydraulic control valve is controlled so as to suppress jack-up when jack-up is detected. Increased the drive limit. As a result, jack-up of the vehicle body can be prevented, and work can be performed in a stable posture.

Hereinafter, an embodiment of a front control device for a hydraulic excavator according to the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an example of a hydraulic excavator to which a front control device according to an embodiment of the present invention is applied. The hydraulic excavator has a front work machine 10 and a vehicle body 20. The vehicle body 20 includes a pair of left and right lower traveling bodies 21 and an upper revolving body 22 that is turnably mounted above the lower traveling bodies 21, and an upper cab 22 is provided with a cab 23.

  The front work machine 10 has a boom 11 pivotally supported at the front of the upper swing body 22, an arm 12 pivotally supported at the boom tip, and a pivot at the arm tip. The bucket 13 is pivotally supported. The boom 11, the arm 12, and the bucket 13 are supported by a boom cylinder 14, an arm cylinder 15, and a bucket cylinder 16, respectively, and rotate in a plane perpendicular to the vehicle width direction by expansion and contraction of the cylinders 14 to 16, respectively. The left and right lower traveling bodies 21 travel by driving the traveling hydraulic motors 24 and 25 (FIG. 2), respectively, and the upper swing body 22 rotates by driving the turning hydraulic motor 26 (FIG. 2).

  FIG. 2 is a diagram illustrating a configuration of the front control device according to the present embodiment. The control unit 30 includes an arithmetic processing unit having a CPU, ROM, RAM, and other peripheral circuits. The control unit 30 includes a boom operation lever 31 for inputting a drive command for the boom 11, an arm operation lever 32 for inputting a drive command for the arm 12, and a bucket operation lever 33 for inputting a drive command for the bucket 13. The turning operation lever 34 for inputting a turning command for the upper turning body 21, the traveling operation levers 35 and 36 for inputting the running commands for the left and right lower traveling bodies 21, the setting device 37, and the upper turning body 22, respectively. The boom angle detector 38 that detects the relative angle (boom angle α) of the boom 11, the arm angle detector 39 that detects the relative angle (arm angle β) of the arm 12 with respect to the boom 11, and the relative of the bucket 13 to the arm 12. A bucket angle detector 40 that detects an angle (bucket angle γ) and an inclination angle θ with respect to a horizontal plane in the front-rear direction of the upper swing body 22 are detected. The inclination angle detector 41, the directional control valve (electromagnetic proportional valve) 51 to 56 of the solenoid is connected. The inclination angle θ becomes positive when the front of the vehicle body is raised.

  The operation levers 31 to 36 are electric lever devices that output an electric signal corresponding to the operation amount as an operation signal. The control unit 30 responds to a signal from the operation levers 31 to 36 with the solenoid of the direction control valves 51 to 56. Output a control signal. Thereby, the direction control valves 51 to 56 are switched, and the flow of pressure oil from the hydraulic pump 50 to the hydraulic cylinders 14 to 16 and the hydraulic motors 23 to 25 is controlled. That is, the flow of pressure oil from the hydraulic pump 50 to the boom cylinder 14 is controlled by switching the control valve 51, and the flow of pressure oil from the hydraulic pump 50 to the arm cylinder 15 is controlled by switching the control valve 52. Is switched to control the flow of pressure oil from the hydraulic pump 50 to the bucket cylinder 16. Further, the flow of pressure oil from the hydraulic pump 50 to the traveling hydraulic motor 23 is controlled by switching the control valve 54, and the flow of pressure oil from the hydraulic pump 50 to the traveling hydraulic motor 24 is controlled by switching the control valve 55. Then, the flow of the pressure oil from the hydraulic pump 50 to the turning hydraulic motor 25 is controlled by switching the control valve 56.

  The setting device 37 is configured by a switch or the like provided on an operation panel in the cab or a grip portion of the operation lever. The setting device 37 is provided with a changeover switch 37a for switching the work mode to the normal mode or the area restriction mode, and a setting switch 37b for instructing the setting of the work area. The changeover switch 37a is an on / off switch such as a toggle switch, for example, and is switched to the area line mode when the changeover switch 37a is turned on, and is switched to the normal mode when turned off.

  The control unit 30 includes an area setting unit 30A that sets a work area, and a front control unit 30B that controls the operation of the front work machine 10 based on the set work area. As shown in FIG. 3, the setting work area is set as the depth (Y coordinate) of the bucket tip in the XY rectangular coordinate system with the boom base end as the origin.

  The region setting process executed by the region setting unit 30A will be described. FIG. 4 is a flowchart illustrating an example of the area setting process. This process is started, for example, by turning on the engine key switch, and a series of processes are repeatedly executed. Note that a reset switch for resetting the setting work area may be provided in the setting device 37, and the area setting process may be started when the reset switch is turned on.

  In step S1, an initial value for the work area is set. The initial value is set to such a depth that the bucket tip does not reach (for example, Y = −20 m). This is because the work area can be set freely even in a state where the movement range of the front work machine 10 is limited by processing in the front control unit 30B described later. In step S2, it is determined whether or not the setting switch 37b of the setting device 37 is turned on. If the determination is affirmative, the process proceeds to step S3.

  In step S3, the lengths L1, L2, and L3 (see FIG. 3) of the boom 11, the arm 12, and the bucket 13 stored in advance in the ROM of the control unit 30 and the boom angle α detected by the angle detectors 38 to 40 are used. , The position (X1, Y1) of the bucket tip P1 is calculated based on the arm angle β, the bucket angle γ, and the inclination angle θ. In step S4, the calculated Y coordinate value Y1 of the bucket tip is set as a work area, and this set work area (Y = Y1) is stored in the RAM of the control unit 30.

  According to the above processing, when setting the work area of the bucket tip, the operator operates the operation levers 31 to 33 to move the bucket tip to the target working depth, and then operates the setting switch 37b. . Thereby, a work area is set, and the operation of the front work machine 10 is limited so as not to exceed the set work area by processing in the front control unit 30B described later.

  A region restriction process executed by the front control unit 30B will be described. FIG. 5 is a flowchart illustrating an example of the area restriction process. This process is started, for example, when the engine key switch is turned on and is repeatedly executed. In step S10, it is determined whether or not the area restriction mode is selected by the changeover switch 37a. If step S10 is affirmed, the process proceeds to step S20, and the operation signals of the operation levers 31 to 36 are read. In step S30, the boom angle α, arm angle β, bucket angle γ, and inclination angle θ detected by the angle detectors 38 to 41 are read. In step S40, the linear equation (Y = Y1) of the setting work area stored in the area setting process is corrected based on the detected inclination angle θ as follows.

  FIG. 6 is a flowchart showing details of the process in step S40. First, in step S41, it is determined whether or not an operation signal is input by operating the operation levers 31 to 33. If it is determined in step S41 that an operation signal has been input, the process proceeds to step S42, and the tilt angle θn at that time is stored in the RAM. When the operation signal is continuously input, the process of step S42 is repeated every predetermined time (period of the area restriction process), and a plurality of inclination angles θ1, θ2,. The

  In step S43, the previous tilt angle θn-1 is subtracted from the stored latest tilt angle θn to calculate the tilt angle deviation Δθ (= θn−θn-1), and the deviation ΔN is time-differentiated to obtain the tilt. A rate of change of corner ΔN ′ is obtained, and it is determined whether ΔN ′ is equal to or greater than a predetermined value ΔNa. The predetermined value ΔNa is a threshold value for determining whether or not the vehicle body 20 is jacked up. At least ΔNa is larger than 0 in order to distinguish it from the case where the excavator is stopped on a sloping ground (ΔN ′ = 0). Is set to a value. When obtaining the tilt angle deviation Δθ, it is preferable to remove the noise by filtering the signal θ from the tilt angle detector 41.

  If it is determined in step S43 that ΔN ′ ≧ ΔNa, that is, the vehicle body 20 is jacked up, the process proceeds to step S44. In step S44, a predetermined value ΔY (for example, 1 cm) is added to the linear equation (Y = Y1) of the operation work area, the linear equation is corrected to Y = Y1 + ΔY, and the corrected linear equation (Y = Y1 + ΔY) is also obtained. Store in RAM. The RAM also stores the linear expression (Y = Y1) before correction set in the area setting process (FIG. 4) as it is.

  On the other hand, if it is determined in step S41 that no operation signal is input, the process proceeds to step S45, and the inclination angle θ is stored as in step S42. In step S46, the linear equation of the setting work area is returned to the value before correction (Y = Y1). If it is determined in step S43 that ΔN ′ <ΔNa, that is, the vehicle body is not jacked, the process proceeds to step S46. When the above process ends, the process proceeds to step S50 in FIG.

  In step S50, the front angle is determined based on the boom angle α, arm angle β, bucket angle γ, and inclination angle θ detected by the angle detectors 38 to 41 and the dimensions of the front work machine 10 and the vehicle body 20 stored in advance. The position and orientation of the work machine 10 are calculated, and the position (X, Y) of the bucket tip P1 (FIG. 3) is calculated.

  In step S60, signals from the angle detectors 39 and 40 are time-differentiated to obtain angular velocities ω2 and ω3 due to the rotation of the arm 12 and the bucket 13, and the driving speeds of the arm cylinder 15 and the bucket cylinder 16 are obtained from the angular velocities ω2 and ω3. Is calculated. Then, the speed vector V at the tip of the bucket is calculated using the drive speed and the dimensions of each part of the front work machine 10, and the vector vector (X-coordinate component) Vx in the direction parallel to the boundary of the speed vector setting work area is perpendicular. A direction vector component (Y coordinate component) Vy is obtained (see FIG. 7).

  In step S70, it is determined whether or not the position of the bucket tip is in the deceleration region. As shown in FIG. 7, the deceleration area is set in a range that is separated from the boundary of the set work area by a predetermined value Y1 upward. The predetermined value Y1 is a value stored in the controller 30 in advance. If step S70 is positive, the process proceeds to step S80. In step S80, arm deceleration processing (processing for reducing the operation command value) for decelerating the operation signal itself of the arm operation lever 32 as deceleration control, and a direction approaching the boundary of the setting work area for the speed vector V at the bucket tip. Processing to reduce the vector component Vy (deceleration direction conversion processing) is performed. In the arm deceleration process, for example, the operation signal of the arm operation lever 32 is multiplied by a predetermined coefficient c1 (0 <c1 <).

  The deceleration direction conversion process in step S80 will be described. As shown in FIG. 8, the control unit 30 stores in advance the relationship between the distance D1 (absolute value) from the boundary of the set work area to the bucket tip and the deceleration vector coefficient h. The characteristic of FIG. 8 is that h = 0 when the distance D1 is larger than the predetermined value Y1, that is, not in the deceleration region, and when the distance D1 becomes smaller than the predetermined value Y1, the deceleration vector decreases as the distance D1 decreases. The coefficient h increases, and h = 1 when the distance D1 = 0.

  In step S80, a vector component in a direction approaching the boundary of the set work area of the velocity vector V at the bucket tip, that is, a deceleration vector VR for subtracting the Y-coordinate component Vy of the XY coordinate system is obtained. That is, the deceleration vector coefficient h corresponding to the distance D1 between the boundary of the set work area and the bucket tip is calculated from the relationship of FIG. 8, and this deceleration vector coefficient h is multiplied by the Y coordinate component Vy of the speed vector V, and further −1. To obtain a deceleration vector VR (= −hVy). When the deceleration vector VR thus obtained is added to the Y coordinate component Vy of the velocity vector V, the amount of decrease in the Y coordinate component Vy of the velocity vector V increases as the distance D1 becomes smaller than the predetermined value y1, and FIG. As shown, the velocity vector V is corrected to the velocity vector Va.

  FIG. 9 shows an example of the locus of the bucket tip when the speed vector V is corrected to the speed vector Va in the deceleration region. When the velocity vector V is constant obliquely downward, the parallel component Vx is constant, and the vertical component Vy decreases as the bucket tip approaches the boundary of the setting work area, that is, as the distance D1 decreases. Accordingly, as the bucket tip approaches the boundary of the setting work area, the angle a formed by Va and Vx decreases, and the locus of the bucket tip has a curved shape along the boundary of the setting work area. At this time, since D1 = 0, h = 1, and VR = −Vy, the corrected velocity vector Va on the boundary of the set work area coincides with the parallel component Vx of the velocity vector V.

  In step S90, the control signal output to the direction control valves 51-56 is calculated. That is, the control signal of the direction control valve 51 corresponding to the deceleration vector VR is calculated as the control signal output to the boom direction control valve 51. Specifically, first, the target value of the angular velocity of the boom 11 corresponding to the deceleration vector VR is calculated, link conversion is performed on the target value, and the operation signal of the boom 11 corresponding to the target value of the boom angular velocity is calculated. Here, outputting this operation signal to the directional control valve 51 and operating the boom 11 means raising the boom so as to obtain the deceleration vector VR, which is the deceleration as shown in FIG. This corresponds to adding the vector VR to the vector component Vy in the vertical direction of the velocity vector V.

  In step S90, an operation signal corresponding to the arm deceleration process in step S80 is calculated as a control signal to be output to the arm direction control valve 52. Further, as control signals output to the other directional control valves 53 to 56, operation signals corresponding to the operations of the operation levers 33 to 36 input in step S20 are calculated. In step S100, the control signals calculated in step S90 are output to the directional control valves 51 to 56, respectively.

  On the other hand, if step S70 is negative, the process proceeds to step S110, and whether the position of the bucket tip is below the set work area (outside the set area), that is, whether it is in the restoration area as shown in FIG. Determine whether. If step S110 is positive, the process proceeds to step S120. In step S120, as a restoration control, an arm deceleration process for decelerating the operation signal itself of the arm operation lever 32 (a process for decreasing the operation command value) and a direction approaching the boundary of the setting work area of the speed vector V at the bucket tip. A process of converting the vector component Vy into a component in a direction toward the boundary of the setting work area (restoration direction conversion process) is performed. In the arm deceleration process, for example, the operation signal of the arm operation lever 32 is multiplied by a predetermined coefficient c2 (0 <c1 <).

  The restoration direction conversion process in step S120 will be described. As shown in FIG. 10, the control unit 30 stores in advance the relationship between the distance D2 (absolute value) from the boundary of the set work area to the bucket tip and the addition restoration vector AR. The characteristic of FIG. 10 is a straight line passing through the origin, and the addition restoration vector AR increases as the distance D2 increases.

  In step S120, first, a reverse vector Ay of Vy, which is a value for canceling the vertical component Vy of the velocity vector V, is obtained. Next, using the relationship shown in FIG. 10, an addition restoration vector AR corresponding to the distance D2 from the boundary of the setting work area to the bucket tip is calculated, and the sum of the reverse direction vector Ay of Vy and the addition restoration vector AR is calculated. Is a restoration vector VR2 (= Ay + AR). When the restored vector VR2 thus obtained is added to the Y coordinate component Vy of the velocity vector V, the vertical vector component Vy decreases as the distance D2 decreases, and the velocity vector V is corrected to the velocity vector Va.

  FIG. 11 shows an example of the locus of the bucket tip when the velocity vector V is corrected to the velocity vector Va in the restoration region. When the velocity vector V is constant obliquely downward, the parallel component Vx is constant, and the vertical component Vy decreases as the bucket tip approaches the boundary of the setting work area, that is, as the distance D2 decreases. Therefore, as the bucket tip approaches the boundary of the setting work area, the angle b formed by Va and Vx decreases, and the locus of the bucket tip becomes a curved shape along the boundary of the setting work area.

  In step S130, the control signal output to the direction control valves 51-56 is calculated. That is, the control signal of the direction control valve 51 corresponding to the restoration vector VR2 is calculated as the control signal output to the boom direction control valve 51. Specifically, first, the target value of the angular velocity of the boom 11 corresponding to the restoration vector VR2 is calculated, link conversion is performed thereon, and the operation signal of the boom 11 corresponding to the target value of the boom angular velocity is calculated. Here, outputting this operation signal to the direction control valve 51 and operating the boom 11 means raising the boom so as to obtain the restored vector VR2, which is restored as shown in FIG. This corresponds to adding the vector VR2 (= Ay + AR) to the vector component Vy in the vertical direction of the velocity vector V.

  In step S130, an operation signal corresponding to the arm deceleration process in step S120 is calculated as a control signal to be output to the arm direction control valve 52. Further, as control signals output to the other directional control valves 53 to 56, operation signals corresponding to the operations of the operation levers 33 to 36 input in step S20 are calculated. In step S100, the control signals calculated in step S130 are output to the direction control valves 51 to 56, respectively.

  If step S110 is negative, that is, if it is determined that the bucket tip position is outside the restricted area above the set work area by a predetermined value Y1, the process proceeds to step S140. In step S140, operation signals corresponding to the operation of the operation levers 31 to 36 input in step S20 are calculated as control signals output to the direction control valves 51 to 56, respectively. In step S100, the control signals calculated in step S140 are output to the direction control valves 51 to 56, respectively. When it is determined in step S10 that the normal mode is selected, the process proceeds to step S150, the operation signals of the operation levers 31 to 36 are read, and a control signal corresponding to the operation signal is calculated in step S140.

A characteristic operation of the front control apparatus according to the present embodiment will be described.
When excavation work is performed with a restriction on the work area in the depth direction, first, the bucket tip P1 is moved to a desired area restriction position by operating the operation levers 31 to 36. When the setting switch 37b is turned on in this state, a work area is set in which the Y coordinate Y1 of the bucket tip is a linear expression (Y = Y1) (step S4). Next, in a state in which the region restriction mode is selected by operating the changeover switch 37a, the front work machine 10 is driven by operating the operation levers 31 to 33 to perform excavation work.

  If the bucket tip is located above the deceleration region, that is, outside the restriction region, neither deceleration control nor restoration control is performed, and control signals corresponding to the operation of the operation levers 31 to 36 are respectively sent to the direction control valves 51 to 56. Is output (step S140). In this case, the front work machine 10 is driven according to the operation amount of the operation levers 31 to 36.

  When the bucket tip enters the deceleration region, a boom raising control signal is output to the boom direction control valve 51 so that the speed vector V and the upward deceleration vector VR corresponding to the bucket position act on the bucket tip P1 (step). S80, step S90). Further, a control signal corresponding to the arm deceleration process is output to the arm direction control valve 52. As a result, the operation of the front work machine 10 is restricted so that the bucket tip does not exceed the set work area, and the locus of the bucket tip is as shown in FIG. At this time, as the distance D1 between the bucket tip and the set work area is shorter, the deceleration vector coefficient h is larger (FIG. 8), so the deceleration vector VR is larger.

  When the bucket tip enters the restoration area below the set work area, the boom raising control signal 51 is sent to the boom direction control valve 51 so that the speed vector V and the upward restoration vector VR2 corresponding to the bucket position act on the bucket tip P1. Is output (step S120, step S130). Further, a control signal corresponding to the arm deceleration process is output to the arm direction control valve 52. As a result, the vertical component of the velocity vector V at the bucket tip is canceled, and a restoring force that returns the bucket tip to the setting work area acts, so that the bucket work tip 10 does not exceed the setting work area. Operation is restricted. As a result, the locus of the bucket tip is as shown in FIG.

  If the vehicle body is jacked up while the bucket tip is in the deceleration area, the correction value ΔY is added to the linear equation (Y = Y1) of the setting work area (Y = Y1 + ΔY), and the apparent setting work area is upward. Shift (step S43). As a result, the deceleration vector VR becomes large and jack-up can be prevented, and excavation work can be performed while the vehicle body posture is stable. In this case, as long as the jack-up continues, the correction value ΔY is repeatedly added, so the deceleration vector VR gradually increases, and the jack-up can be prevented quickly.

  When the vehicle body is jacked up with the bucket tip approaching the set work area, and the apparent set work area is shifted upward from the bucket tip position, the bucket restoration point VR2 is larger than the deceleration vector VR at the bucket tip. In this case, jack-up can be prevented promptly. If the vehicle body jacks up when the bucket tip is above the deceleration region, the apparent setting work region shifts upward and the deceleration vector VR acts on the bucket tip. Can be prevented.

According to the present embodiment, the following operational effects can be achieved.
(1) The speed vector V of the bucket tip is calculated based on the actual angular velocity of the arm 12 and the bucket 13, and the deceleration vector VR or the restoration vector VR2 is calculated based on the speed vector V and the bucket tip position (X, Y). The boom 11 was controlled so as to obtain these vectors VR and VR2. Thereby, even if the arm 12 and the bucket 13 do not operate according to the operation command values of the operation levers 32 and 33 due to a load during excavation, the operation of the front work machine 10 is limited so that the bucket tip does not exceed the set work area. can do. Further, excavation work for moving the bucket tip along the set work area can be easily performed.

(2) During excavation work by operating the operation levers 31 to 33, it is determined whether or not the vehicle body 20 is jacked up. If it is determined that the jack is up, the linear formula (Y = Y1) of the set work area is shifted upward. (Step S44). As a result, the deceleration vector VR acting on the bucket tip is increased, and jack-up of the vehicle body 20 can be prevented. As a result, the work can be performed in a stable posture.
(3) When jackup is continuously detected, the correction value ΔY is continuously added, so that the amount of shift upward in the excavation work area gradually increases, and jackup can be prevented quickly.
(4) After jacking up is no longer detected after shifting the setting work area upward, the setting work area is restored (reset), so it is easy to work with the work area limited to the original setting work area. You can return to
(5) When the rate of increase ΔN ′ of the inclination angle θ of the vehicle body 20 exceeds the predetermined value ΔNa, it is determined that jack-up occurs. Jackup can be detected accurately.

  In the above embodiment, the predetermined value ΔY is added as a correction value when jackup is detected. However, the value of the predetermined value ΔY may be changed according to various conditions. For example, when the front of the vehicle is jacked up on an inclined slope with an upward slope, the inclination angle θ of the vehicle body 20 becomes larger than when the forward of the vehicle is jacked up on an inclined ground with a downward slope or on a flat ground. Therefore, when the front of the vehicle body is jacked up on an uphill slope, the predetermined value ΔY may be set to a larger value.

  Further, when the upper turning body 22 and the lower traveling body 21 are oriented in substantially the same direction (the turning angle is about 0 ° or about 180 °) and in the substantially right angle direction (the turning angle is about 90 ° or about 270 °) has a larger ground contact area of the lower traveling body 22 at the time of jack-up than other turning angles (for example, 45 °). The larger the contact area at jack-up, the more stable the vehicle body posture at jack-up is. Therefore, the predetermined value ΔY may be reduced when the turning angle has a large contact area at jack-up. In this case, the turning angle of the upper turning body 22 may be detected by a turning angle detector. Any configuration of the turning angle detector as the turning detection means may be used.

  In the above embodiment, the operation levers 31 to 33 as the operation members are constituted by electric levers, and a drive command for the front work machine 10 is input according to the operation of the operation levers 31 to 33. It is good also as an operation lever. Therefore, the configuration of the directional control valves 51 to 53 for controlling the flow of pressure oil to the hydraulic cylinders 14 to 16 as hydraulic actuators is not limited to that described above. The angle detectors 38 to 40 detect the boom angle α, arm angle β, and bucket angle γ to detect the position of the bucket tip, that is, the excavation position by the front work machine 10, but the strokes of the cylinders 14 to 16 are detected. The excavation position may be detected by detection, and the position detection means is not limited to that described above.

  Although the work area is set to a linear expression of Y = Y1 by the operation of the setting device 37, the mode of the linear expression is not limited to this, and the work area is, for example, a linear expression of Y = aX + b (a and b are constants). May be set. In this case, for example, in order to set the work area, the bucket 13 is moved to two arbitrary positions, the setting switch 37b is turned on, and the tip position (X, Y) of the bucket 13 is calculated at each position. The constants a and b may be set based on the position. Further, instead of operating the setting switch 37b, the formula of the work area may be directly input as a numerical value.

  In the above embodiment, the driving of the boom direction control valve 51 and the arm direction control valve 52 is controlled by the deceleration process and the restoration process in the front control unit 30B. However, the hydraulic pressure is set so that the excavation position does not exceed the set work area. If the drive of the control valve is limited, the configuration of the limiting means is not limited to this. For example, the operation of the bucket direction control valve 53 may be limited. In the above embodiment, the limit amount of the excavation work area is increased by increasing the set work area by a predetermined value ΔY at the time of jackup detection, but the configuration of the jackup suppression means is not limited to this. . For example, the predetermined value ΔY may be changed according to a change in the X coordinate of the bucket tip.

  In the above embodiment, the inclination angle detector 41 as the inclination angle detection means detects the inclination angle θ in the front-rear direction of the vehicle body, and determines whether the increase rate ΔN ′ of the inclination angle is equal to or greater than a predetermined value ΔNa. Although the control unit 30 determines that jackup is detected, the configuration of the jackup detection means is not limited to this.

  In the above embodiment, the case where the present invention is applied to the hydraulic excavator in which the front work machine 10 has three front members, that is, the boom 11, the arm 12, and the bucket 13, is described, but the boom 11 has the first boom and the second boom. The present invention may also be applied to a hydraulic excavator having a two-piece type or offset type front working machine. In this case, for example, the first boom closest to the vehicle body 20 may be handled as the boom 11 of the above embodiment. That is, the present invention is not limited to the front control device of the embodiment as long as the features and functions of the present invention can be realized.

1 is a side view showing an example of a hydraulic excavator to which a front control device according to an embodiment of the present invention is applied. The figure which shows the structure of the front control apparatus which concerns on this Embodiment. The figure for demonstrating the area | region setting of the front control apparatus which concerns on this Embodiment. The flowchart which shows an example of the area | region setting process which concerns on this Embodiment. The flowchart which shows an example of the area | region limitation process which concerns on this Embodiment. The figure which shows the detail of step S40 of FIG. The figure which shows the correction method of the velocity vector in a deceleration area | region and a decompression | restoration area | region. The figure which shows the relationship of the deceleration vector with respect to the distance from the bucket front-end | tip of a deceleration area | region to a setting work area | region. The figure which shows an example of the locus | trajectory of the bucket front end in deceleration control. The figure which shows the relationship of the relationship of the restoring vector for addition with respect to the distance from the bucket front-end | tip of a restoring area to a setting work area. The figure which shows an example of the locus | trajectory of the bucket front-end | tip in restoration control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Front working machine 14 Boom cylinder 15 Arm cylinder 16 Bucket cylinder 20 Car body 21 Lower traveling body 22 Upper turning body 30 Control units 31-33 Operation levers 51-53 Direction control valve 37 Setting device 38 Boom angle detector 39 Arm angle detector 40 Bucket angle detector 41 Tilt angle detector

Claims (4)

A vehicle body having a traveling body and a revolving body capable of turning with respect to the traveling body;
Attached to the vehicle body, and a front work device of articulated with pivotable boom in the vertical direction, the arm, the bucket,
A hydraulic actuator that drives the front work machine;
An operation member for inputting a drive command of the front work machine;
A hydraulic control valve for controlling the flow of driving pressure oil to the hydraulic actuator according to the operation of the operating member;
Turning detection means for detecting a turning position of the turning body relative to the traveling body;
Position detecting means for detecting an excavation position by the front work machine;
In a front control device for a hydraulic excavator, comprising: a restricting means for restricting driving of the hydraulic control valve so that an excavation position detected by the position detecting means does not exceed a set work area in a depth direction of the front work machine. ,
Jackup detection means for detecting jackup of the vehicle body;
When jackup is detected by the jackup detection means, the jackup suppression means for increasing the restriction amount by the restriction means so as to suppress jackup ,
The front control device of a hydraulic excavator, wherein the jack-up suppressing means changes the degree of increase of the restriction amount by the restriction means according to the turning position detected by the turning detection means . The front control apparatus of the hydraulic excavator according to claim 1,
The front control device for a hydraulic excavator, wherein the jackup suppression means performs a correction to shift the setting work area upward when the jackup is detected. The front control device for a hydraulic excavator according to claim 2,
The jackup suppression means resets the correction of the setting work area when jackup is no longer detected by the jackup detection means after performing the correction to shift the setting work area upward. Front control device of hydraulic excavator. In the front control apparatus of the hydraulic excavator according to any one of claims 1 to 3,
The jackup detection means includes:
An inclination angle detecting means for detecting an inclination angle of the vehicle body in the longitudinal direction;
A front control device for a hydraulic excavator, comprising: a determination unit that determines that jack-up occurs when a rate of increase in the tilt angle detected by the tilt angle detection unit is equal to or greater than a predetermined value.

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