JP2020012288A - Swing-type hydraulic working machine - Google Patents

Abstract

To provide a swing-type hydraulic working machine having a control structure capable of securing the start of a swing motor even on a slope without detecting the tilt direction and the tilt angle of an upper swing body, that is, without using a tilt sensor.SOLUTION: A controller 20 provided in a swing-type hydraulic working machine is configured to perform limit control when the pressure of a second hydraulic pump 14, the amount of swing movement of an upper swing body 2, or the swing speed of the upper swing body 2 has not risen to a predetermined threshold, and to perform normal control otherwise, or to perform limit control for a set time, and to perform normal control after the set time has passed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a swing hydraulic working machine such as a hydraulic shovel.

  As this type of technology, for example, there is a technology described in Patent Document 1. The technique described in Patent Literature 1 relates to control of a swing hydraulic working machine, and presupposes that a hydraulic fluid from a first hydraulic pump and a second hydraulic pump are combined and supplied to a boom cylinder in a boom raising operation. However, in the turning operation, the control structure is such that hydraulic oil from the second hydraulic pump is supplied to the turning motor.

  In the revolving hydraulic working machine having such a control configuration, when the revolving drive is performed in a state where the upper revolving structure is inclined rather than horizontal, the upper revolving structure acts on the upper revolving structure depending on the revolving direction of the upper revolving structure. It is necessary to perform the turning drive against the gravitational force, and the pressure of the hydraulic oil required for the turning drive becomes higher than the pressure required for the turning drive in the horizontal state. In this case, if much of the hydraulic oil from the second hydraulic pump is distributed to the boom cylinder, the turning drive force will be insufficient, and in the worst case, turning may not be started.

  Therefore, the swing hydraulic working machine described in Patent Literature 1 is provided with the following control configuration so as to reliably enable swing drive regardless of the inclination of the upper swing body. The swing hydraulic working machine includes an inclination sensor that detects an inclination direction and an inclination angle of the upper swing body. Then, the controller determines whether or not the turning direction is a hill-climbing direction against the gravity acting on the upper slewing body based on the leaning direction detected by the tilt sensor. The opening degree of the actuator control valve is reduced so as to limit the flow rate of the hydraulic oil distributed to the boom cylinder as the inclination angle of the actuator control valve increases.

  According to the above configuration, appropriate distribution of hydraulic oil to the swing motor and the boom cylinder can be performed so that the swing drive can be reliably performed regardless of the inclination of the upper swing body.

JP 2017-89168 A

  However, the turning hydraulic working machine described in Patent Literature 1 has the following problems. The pivot type hydraulic working machine described in Patent Document 1 requires an inclination sensor for detecting an inclination direction and an inclination angle of the upper revolving structure, and therefore, costs increase accordingly. Further, software (control logic) for controlling the opening of the actuator control valve based on the signal from the tilt sensor is required, and the control is complicated.

  The present invention has been made in view of the above circumstances, and has as its object to detect a turning motor without detecting a tilt direction and a tilt angle of an upper turning body, that is, without using a tilt sensor, even on a sloping ground. To provide a swing type hydraulic working machine having a control configuration capable of ensuring the start of the hydraulic working machine.

  A swing hydraulic working machine according to the present invention includes a lower traveling structure, an upper revolving structure mounted on the lower traveling structure, a first hydraulic pump mounted on the upper revolving structure, and a second hydraulic pump. A hydraulic actuator that operates by receiving a supply of hydraulic oil discharged from a first hydraulic pump; and a turning motor that turns the upper revolving unit, and receives a supply of hydraulic oil discharged by the second hydraulic pump. A swing motor that operates, an actuator operation device that is provided with an actuator operation for commanding the operation of the hydraulic actuator, and is interposed between the second hydraulic pump and the swing motor, and is discharged by the second hydraulic pump. A rotation control valve that supplies and discharges hydraulic oil to and from the rotation motor, and is interposed between the second hydraulic pump and the rotation control valve, and is discharged by the second hydraulic pump. The hydraulic fluid, a distribution valve for distributing the said hydraulic actuator and said swing motor, and a, and a controller for controlling the distribution valve. The controller performs a normal control of changing an opening degree of the distribution valve so as to distribute and supply a basic combined flow rate of hydraulic oil from the second hydraulic pump to the hydraulic actuator according to an operation amount of the actuator operation device. A normal control unit, and a restriction control unit that performs restriction control to change the opening of the distribution valve so as to restrict the distribution and supply amount of hydraulic oil from the second hydraulic pump to the hydraulic actuator. I have. At the time of the combined operation of the operation of the hydraulic actuator and the operation of the swing motor, the controller sets the pressure of the second hydraulic pump, the swing amount of the upper swing body, or the swing speed of the upper swing body to a predetermined value. If it does not rise to the threshold, perform the limit control, otherwise perform the normal control, or perform the limit control for a set time, perform the normal control after the set time Is configured.

  According to this configuration, the start of the turning motor can be ensured even on a slope without detecting the tilt direction and the tilt angle of the upper turning body, that is, without using the tilt sensor. After the start of the swing motor is secured, the operability of the swing motor and the operability of the hydraulic actuator can be secured.

  In a preferred embodiment of the present invention, the controller determines whether the pressure of the second hydraulic pump, the amount of swing movement of the upper swing body, or the swing speed of the upper swing body has increased to a predetermined threshold. A controller for determining whether or not the upper revolving unit has a pressure of the second hydraulic pump, a revolving movement amount of the upper revolving unit, If it is determined that the turning speed has not risen to the predetermined threshold, the limiting control is performed, and if not, the normal control is performed.

  According to this configuration, when the combined operation of the operation of the hydraulic actuator and the operation of the swing motor is started, it is possible to suppress the operation of the hydraulic actuator from being always restricted. For example, on a flat ground, when the above-described combined operation is performed, the control may be limited, but by entering the normal control, the hydraulic actuator can be operated at the same speed as before, and Operability is also ensured.

  In a preferred embodiment of the present invention, the limit control start determination unit sets the predetermined threshold value to a larger value as the turning pilot pressure input to the turning control valve is larger.

  According to this configuration, the turning motor can be more reliably started.

  In a preferred embodiment of the present invention, the controller has a limit control continuation determination unit that determines whether or not the swing motor has entered an operation stable state after startup, and the controller has the limit control continuation determination unit. In the section, when it is not determined that the operation of the swing motor is stable, the limit control is performed, and when it is determined that the operation of the swing motor is stable, the normal control is performed.

  According to this configuration, after the start of the swing motor is secured, the operability of each of the swing operation of the swing motor and the hydraulic actuator can be secured by the normal control.

  In a preferred embodiment of the present invention, the limit control continuation determining unit determines whether or not the swing motor has entered an operation stable state after startup based on the magnitude of the pressure of the second hydraulic pump.

  Whether the swing motor has entered the stable operation state is indicated by the pressure of the second hydraulic pump. According to the above configuration, the controller can determine whether or not the swing motor has entered the stable operation state.

  In a preferred embodiment of the present invention, the limit control continuation determining unit, when the pressure of the second hydraulic pump drops to a set pressure set based on the magnitude of the pressure of the first hydraulic pump, It is determined that the operation of the swing motor has been stabilized.

  According to this configuration, the turning motor can be more reliably started.

  According to the present invention, there is provided a control structure capable of ensuring the start of the swing motor even on a slope without detecting the tilt direction and the tilt angle of the upper swing body, that is, without using a tilt sensor. A swing hydraulic working machine can be provided.

FIG. 2 is a side view of a hydraulic excavator that is a revolving hydraulic working machine. It is a figure showing the hydraulic circuit of a 1st embodiment carried in the above-mentioned hydraulic shovel. 5 is a flowchart illustrating a control operation according to the first embodiment. 9 is a table showing a continuation condition of the restriction control. It is a figure which shows an example of the time series change of the pressure of a 1st hydraulic pump and the pressure of a 2nd hydraulic pump at the time of the combined operation of a boom raising operation and a turning operation. It is a figure showing a hydraulic circuit of a 2nd embodiment. It is a flowchart which shows the control operation of 2nd Embodiment. It is a figure showing a hydraulic circuit of a 3rd embodiment. It is a flowchart which shows the control operation of 3rd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the hydraulic excavator described below, but can be widely applied to a work machine including an upper swing body and operating using hydraulic pressure as main power.

(Configuration of hydraulic excavator)
As shown in FIG. 1, the excavator 100 includes a lower traveling unit 1 and an upper revolving unit 2 mounted on the lower traveling unit 1. The upper revolving superstructure 2 includes a cab 3 as a driver's cab, and an engine room 4 is provided at a rear portion. A boom 5 is attached to a front portion of the upper swing body 2, and an arm 6 is attached to a tip of the boom 5, and a bucket 7 is attached to a tip of the arm 6. The boom 5, the arm 6, and the bucket 7 are driven by a boom cylinder 8, an arm cylinder 9, and a bucket cylinder 10, respectively. Each of the boom cylinder 8, the arm cylinder 9, and the bucket cylinder 10 is a hydraulic actuator. For example, the boom cylinder 8 drives the boom 5 in the upward direction and the downward direction by extension and contraction, respectively.

(Control configuration of hydraulic excavator (first embodiment))
FIG. 2 shows a portion of the hydraulic circuit mounted on the hydraulic excavator 100 that is involved in the swing drive of the upper swing body 2 and the up-and-down drive of the boom 5. As shown in FIG. 2, in addition to the boom cylinder 8, the hydraulic excavator 100 includes an engine 12, a first hydraulic pump 13 and a second hydraulic pump 14 connected to an output shaft of the engine 12, and a pilot pump 15. , A turning motor 11, a boom remote control valve 21 (actuator operating device), a turning remote control valve 22, and the like. Note that the first hydraulic pump 13 and the second hydraulic pump 14 are mounted on the upper swing body 2. Each of the first hydraulic pump 13 and the second hydraulic pump 14 includes a regulator. The swing motor 11 is a hydraulic motor for swinging and driving the upper swing body 2.

  The hydraulic circuit shown in FIG. 2 includes a boom control valve 16 (actuator control valve), a swing control valve 17, a distribution valve 18, and a pilot pressure operation valve 19. Among these valves, the boom control valve 16, the swing control valve 17, and the distribution valve 18 are hydraulic pilot switching valves, and receive supply of pilot pressure from the pilot pump 15 so as to correspond to the magnitude of the pilot pressure. It operates for the stroke that has been made. On the other hand, the pilot pressure control valve 19 is an electromagnetic proportional valve, and controls the pilot pressure supplied from the pilot pump 15 to the pilot port 18A of the distribution valve 18 by controlling the opening degree of the controller 20.

  The boom control valve 16 is a center bypass type directional switching valve that supplies and discharges hydraulic oil discharged by the first hydraulic pump 13 to and from the boom cylinder 8, and is interposed between the first hydraulic pump 13 and the boom cylinder 8. I do. The boom control valve 16 is a three-position hydraulic pilot switching valve and has a pair of pilot ports 16A and 16B. When a pilot pressure equal to or more than a predetermined value is supplied to the pilot port 16A, the boom control valve 16 shifts from the neutral position 16n to the boom raising position 16a by a stroke corresponding to the magnitude of the pilot pressure. Is supplied to the head side chamber 8H of the boom cylinder 8 at a flow rate corresponding to the stroke. Thus, the boom cylinder 8 operates in the boom raising direction at a speed corresponding to the stroke. Conversely, when a pilot pressure equal to or higher than a predetermined value is supplied to the pilot port 16B, the boom control valve 16 shifts from the neutral position 16n to the boom lowering position 16b by a stroke corresponding to the magnitude of the pilot pressure, and The hydraulic oil from the pump 13 is supplied to the rod-side chamber 8R of the boom cylinder 8. Thereby, the boom cylinder 8 operates in the boom lowering direction.

  The turning control valve 17 is a center bypass type directional switching valve that supplies and discharges hydraulic oil discharged from the second hydraulic pump 14 to the turning motor 11, and is interposed between the second hydraulic pump 14 and the turning motor 11. I do. The turning control valve 17 is a three-position hydraulic pilot switching valve and has a pair of pilot ports 17A and 17B. The turning control valve 17 shifts from the neutral position 17n to the left turning position 17a by a stroke corresponding to the magnitude of the pilot pressure when the pilot pressure is supplied to the pilot port 17A to the pilot port 17A. Is supplied to the first port 11a of the turning motor 11 at a flow rate corresponding to the stroke. Thereby, the turning motor 11 operates in the left turning direction at a speed corresponding to the stroke. Conversely, when a pilot pressure equal to or greater than a predetermined value is supplied to the pilot port 17B, the turning control valve 17 shifts from the neutral position 17n to the right turning position 17b by a stroke corresponding to the magnitude of the pilot pressure. The hydraulic oil from the hydraulic pump 14 is supplied to the second port 11b of the turning motor 11 at a flow rate corresponding to the stroke. Thus, the turning motor 11 operates in the right turning direction at a speed corresponding to the stroke.

  The distribution valve 18 is a valve that distributes hydraulic oil discharged by the second hydraulic pump 14 to the swing motor 11 and the boom cylinder 8, and is interposed between the second hydraulic pump 14 and the swing control valve 17. The distribution valve 18 is a two-position hydraulic pilot switching valve and has a single pilot port 18A. The distribution valve 18 shifts from the neutral position 18n to the boom merging position 18a by a stroke corresponding to the magnitude of the pilot pressure when the pilot pressure is supplied to the pilot port 18A to the pilot port 18A. The hydraulic oil is supplied to the head side chamber 8H of the boom cylinder 8 at a flow rate corresponding to the stroke. Thereby, the driving of the boom cylinder 8 in the raising direction is accelerated at a rate corresponding to the stroke.

  The boom remote control valve 21 is an actuator operation device in which an actuator operation for commanding the operation of the boom cylinder 8 which is a hydraulic actuator is given by an operator, and is linked to the boom operation lever 21a and the movement of the boom operation lever 21a. And a valve body 21b that operates to open the valve. The boom control valve 16 operates in a direction corresponding to the direction of the operation given to the boom operation lever 21a for a stroke corresponding to the amount of the operation.

  The turning remote control valve 22 is a turning operation device to which an operation for commanding the operation of the turning motor 11 is given by an operator, and is a valve that opens and links with the turning operation lever 22a and the movement of the turning operation lever 22a. And a main body 22b. The turning control valve 17 operates in a direction corresponding to the direction of the operation given to the turning operation lever 22a for a stroke corresponding to the amount of the operation.

  A plurality of sensors 23, 24, 25, 26A, and 26B are arranged in the hydraulic circuit shown in FIG. The plurality of sensors 23, 24, 25, 26A, and 26B include a first hydraulic pump pressure sensor 23, a second hydraulic pump pressure sensor 24, a boom raising pilot pressure sensor 25, and a pair of turning pilot pressure sensors 26A, 26B.

  The first hydraulic pump pressure sensor 23 is a pressure sensor that detects a discharge pressure of the first hydraulic pump 13, and the second hydraulic pump pressure sensor 24 is a pressure sensor that detects a discharge pressure of the second hydraulic pump 14. The boom raising pilot pressure sensor 25 is a sensor that detects a pilot pressure supplied to a pilot port 16A of the boom control valve 16. The turning pilot pressure sensors 26A and 26B are sensors that detect a pilot pressure (turning pilot pressure) supplied to the pilot ports 17A and 17B of the turning control valve 17.

  The detection signals of the sensors 23, 24, 25, 26A, and 26B are input to the controller 20 as electric signals.

  The distribution valve 18 is controlled by a controller 20. The controller 20 controls the distribution valve 18 via the pilot pressure control valve 19. The pilot pressure control valve 19 opens at an opening proportional to the excitation current supplied from the controller 20 to the solenoid 19A, whereby the pilot pressure supplied to the pilot port 18A of the distribution valve 18 changes.

  The controller 20 includes a normal control unit 53, a restriction control unit 54, a restriction control start determination unit 51, and a restriction control continuation determination unit 52.

<Normal control>
The normal control unit 53 distributes and supplies the operating oil at the basic combined flow rate from the second hydraulic pump 14 to the boom cylinder 8 according to the amount of operation of the boom operation lever 21a of the boom remote control valve 21 as an actuator operating device in the boom raising direction. Thus, a control unit that performs normal control without energizing the solenoid 19A of the pilot pressure control valve 19 is configured. The operation amount of the boom operation lever 21a in the boom raising direction is detected by the boom raising pilot pressure sensor 25.

<Limit control>
The restriction control unit 54 changes the opening of the distribution valve 18 by energizing the solenoid 19A of the pilot pressure control valve 19 so as to restrict the distribution and supply amount of hydraulic oil from the second hydraulic pump 14 to the boom cylinder 8. A control unit for performing the restriction control is configured. It is to be noted that limiting the distribution supply amount of the hydraulic oil from the second hydraulic pump 14 to the boom cylinder 8 means that the hydraulic oil is supplied from the second hydraulic pump 14 with a smaller amount than the corresponding basic combined flow rate in the case of the normal control. That is, the supply of hydraulic oil from the second hydraulic pump 14 to the boom cylinder 8 is reduced to zero.

  The restriction control start determination unit 51 is configured to determine whether the pressure (discharge pressure) of the second hydraulic pump 14 has increased to a predetermined threshold.

  Further, as will be described in detail later, the restriction control continuation determining unit 52 is configured to determine whether or not the turning motor 11 has entered the stable operation state after starting.

(Control flow)
Specific control performed by the controller 20 will be described with reference to a flowchart shown in FIG.

  The controller 20 sets the restriction start flag and the restriction continuation flag to "OFF" as the initial value setting of each flag (step S1). The controller 20 captures signals from the sensors 23, 24, 25, 26A, 26B and the like (step S2). The controller 20 determines whether there is a boom raising operation signal and a turning operation signal (step S3). The determination of the presence or absence of the boom raising operation signal and the turning operation signal is made using signals from the boom raising pilot pressure sensor 25 and the turning pilot pressure sensor 26A (or 26B) taken into the controller 20. If there is no signal for either the boom raising operation signal or the turning operation signal (NO in step S3), the normal control unit 53 of the controller 20 performs the normal control (step S4).

  On the other hand, if both the boom raising operation signal and the turning operation signal are present (YES in step S3), controller 20 determines whether the restriction start flag is “OFF” (step S5). When the restriction start flag is “OFF” (YES in step S5), the restriction control start determination unit 51 of the controller 20 determines the magnitude of the signal from the pivot pilot pressure sensor 26A (or 26B) (the magnitude of the pivot pilot pressure). ) Is set (step S6). Specifically, the limit control start determination unit 51 sets the threshold value Px to a larger value as the turning pilot pressure input to the turning control valve 17 is larger. The threshold value Px for starting the limit control may be an arbitrary value determined in advance (preliminarily input to the controller 20) regardless of the magnitude of the turning pilot pressure.

  Then, the restriction control start determining unit 51 determines whether the pressure P2 of the second hydraulic pump 14 detected by the second hydraulic pump pressure sensor 24 has increased to the threshold value Px (Step S7). If P2 <Px, that is, if the pressure P2 of the second hydraulic pump 14 has not risen to the threshold value Px (YES in step S7), the restriction control start determination unit 51 sets the restriction start flag to “ON” ( Step S8). When P2 <Px is not satisfied (NO in step S7), that is, when the pressure P2 of the second hydraulic pump 14 is sufficiently high, the normal control unit 53 of the controller 20 performs the normal control (step S4). ).

  The controller 20 determines whether the restriction continuation flag is “OFF” in the case of NO in Step 5 (= in the case where the restriction start flag is “ON”) and after performing Step 8 (Step S9). . If the restriction continuation flag is “OFF” (YES in step S9), the controller 20 sets the restriction continuation flag to “ON” (step S10), and the restriction control unit 54 of the controller 20 performs the restriction control (step S10). S11).

  On the other hand, when the restriction continuation flag is “ON” (NO in step S9), the restriction control continuation determination unit 52 of the controller 20 determines whether or not the swing motor 11 has entered the operation stable state after the start, that is, the continuation of the restriction control. It is determined whether the condition is satisfied (step S12). FIG. 4 shows a list of determination methods (determination methods) for determining whether the continuation condition of the restriction control is satisfied. FIG. 4 is a list showing various determination methods in step S12 shown in FIG. As shown in FIG. 4, there are a plurality of methods for determining whether or not the continuation condition of the restriction control is satisfied. Hereinafter, the determination method described in FIG. 4 will be described.

  No. shown in FIG. The determination methods 1 to 3 are methods for determining whether or not the swing motor 11 has entered the stable operation state after startup, based on the magnitude of the pressure of the second hydraulic pump 14.

  No. In the first determination method, the limit control continuation determination unit 52 of the controller 20 determines that the pressure P2 of the second hydraulic pump 14 drops to the set pressure P2s set based on the magnitude of the pressure P1 of the first hydraulic pump 13. It is determined that the operation of the swing motor 11 is stable, that is, the continuation condition of the limit control is not satisfied.

  Specifically, when P2 ≦ P2s, the restriction control continuation determination unit 52 determines that the operation of the swing motor 11 is stable, that is, the restriction control continuation condition is not satisfied (NO in step S12). The controller 20 sets the restriction start flag and the restriction continuation flag to “OFF” (steps S13 and S14). Then, the normal control unit 53 of the controller 20 performs the normal control (Step S4). If P2> P2s, the limit control continuation determination unit 52 determines that the operation of the swing motor 11 is not stable, that is, the limit control continuation condition is satisfied (YES in step S12), The restriction control unit 54 performs the restriction control (step S11).

  Here, the set pressure P2s (set pressure of the second hydraulic pump 14) set based on the magnitude of the pressure P1 of the first hydraulic pump 13 is, for example, as shown in FIG. Thirteen pressures are set as P1 + 10 MPa. On the other hand, since the pressure P1 of the first hydraulic pump 13 may increase as shown in FIG. 5, when the pressure P1 increases, the set pressure P2s also increases. The time when the pressure P1 of the first hydraulic pump 13 rises is, for example, when a lot of earth and sand enters the bucket 7. In addition, in determining whether or not to continue the limit control, turning is performed by using a set pressure P2s (set pressure of the second hydraulic pump 14) set based on the magnitude of the pressure P1 of the first hydraulic pump 13. Activation of the motor 11 can be ensured more reliably.

  No. In the determination method of 2, when the pressure P2 of the second hydraulic pump 14 drops to the arbitrarily set fixed set pressure P2s, the operation of the swing motor 11 is stabilized. That is, it is determined that the continuation condition of the restriction control is not satisfied.

  For example, when P2 ≦ P2s (for example, a fixed set pressure such as 20 MPa), the limit control continuation determining unit 52 determines that the operation of the swing motor 11 is stable, that is, the limit control continuation condition is not satisfied. . When P2> P2s, the limit control continuation determining unit 52 determines that the operation of the swing motor 11 is not stable, that is, that the continuation condition of the limit control is satisfied.

  No. In the determination method of 3, when the pressure P2 of the second hydraulic pump 14 starts to drop, the limit control continuation determination unit 52 of the controller 20 stabilizes the operation of the swing motor 11, that is, satisfies the limit control continuation condition. If the pressure P2 of the second hydraulic pump 14 is increasing or constant, the operation of the swing motor 11 is not stable. It is determined that the condition is satisfied. In addition, please refer to FIG. 5 for a series of changes of the increase, the constant, and the decrease of the pressure P2.

  No. shown in FIG. The determination methods 4 to 9 will also be described in order.

  No. In the determination method of No. 4, the restriction control continuation determination unit 52 of the controller 20 determines that the operation of the swing motor 11 has stabilized after a predetermined time has elapsed since the pressure P2 of the second hydraulic pump 14 became constant, that is, the restriction control. If it is determined that the continuation condition is not satisfied, and the pressure P2 of the second hydraulic pump 14 is not constant (= the pressure P2 is increasing), or if a predetermined time has not elapsed since the constant, turning is performed. It is determined that the operation of the motor 11 is not stable, that is, the condition for continuing the limit control is satisfied.

  No. In the determination method of No. 5, the restriction control continuation determination unit 52 of the controller 20 determines that the operation of the rotation motor 11 has stabilized after a predetermined time has elapsed from the start of the composite operation (= boom raising operation + rotation operation), that is, the restriction control. It is determined that the continuation condition is not satisfied. Otherwise, it is determined that the operation of the swing motor 11 is not stable, that is, the continuation condition of the limit control is satisfied.

  No. In the determination method of No. 6, the limit control continuation determination unit 52 of the controller 20 determines that the turning speed of the upper revolving unit 2 has reached a speed corresponding to the operation amount given to the turning operation lever 22 a of the turning remote control valve 22. It is determined that the operation of the motor 11 is stable, that is, the continuation condition of the limit control is not satisfied. If not, the operation of the swing motor 11 is not stable, that is, the continuation condition of the limit control is satisfied. Is determined. In the case of this determination method, the excavator 100 has a turning speed sensor that detects the turning speed of the upper turning body 2, and the turning speed sensor is attached to, for example, the lower traveling body 1. The detection signal of the turning speed sensor is input to the controller 20 as an electric signal. For example, a gyro sensor is used as the turning speed sensor.

  No. In the determination method of 7, the limit control continuation determination unit 52 of the controller 20 determines that the operation of the turning motor 11 is stable when the amount of turning movement of the upper revolving superstructure 2, that is, the amount of turning movement is equal to or greater than a specified value. It is determined that the continuation condition of the limit control is not satisfied. Otherwise, it is determined that the operation of the swing motor 11 is not stable, that is, the continuation condition of the limit control is satisfied. In the case of this determination method, the excavator 100 has a turning movement amount sensor for detecting the turning movement amount of the upper turning body 2, and the turning movement amount sensor is attached to, for example, the lower traveling body 1. The detection signal of the turning movement sensor is input to the controller 20 as an electric signal. For example, a gyro sensor is used as the turning movement amount sensor.

  No. In the determination method of 8, the limit control continuation determination unit 52 of the controller 20 determines that the pressure P2 of the second hydraulic pump 14 has dropped to the limit control start threshold Px set in step S6, that is, P2 ≦ Px In this case, it is determined that the operation of the swing motor 11 is stable, that is, the condition for continuing the limit control is not satisfied. Otherwise, the operation of the swing motor 11 is not stable, that is, It is determined that the condition is satisfied.

  No. In the determination method of No. 9, the restriction control continuation determination unit 52 of the controller 20 determines that the operation of the swing motor 11 is stable when the flow rate of the hydraulic pump starts to increase, that is, the restriction control continuation condition is not satisfied. Otherwise, it is determined that the operation of the swing motor 11 is not stable, that is, that the condition for continuing the limit control is satisfied. In this case, when the torques of the first hydraulic pump 13 and the second hydraulic pump 14 are distributed, the flow rate of the first hydraulic pump 13, the flow rate of the second hydraulic pump 14, or the flow rate of the first hydraulic pump 13 The flow rate obtained by summing the flow rate of the two hydraulic pumps 14 is used for the determination. When the torques of the first hydraulic pump 13 and the second hydraulic pump 14 are improper, the flow rate of the second hydraulic pump 14 is used for the determination. In the case of this determination method, a flow meter for detecting the flow rate of the hydraulic pumps 13 and 14 is provided.

  In addition, No. shown in FIG. In the determination methods 1 to 4 and 8, the pressure acting on the swing motor 11 may be used instead of the pressure P2 of the second hydraulic pump 14. In this case, a pressure sensor for detecting the pressure acting on the turning motor 11 is required.

(2nd Embodiment)
FIG. 6 is a diagram illustrating a hydraulic circuit according to a second embodiment mounted on the hydraulic excavator 100. FIG. 7 is a flowchart illustrating a control operation according to the second embodiment. Hereinafter, the differences of the second embodiment from the first embodiment will be mainly described.

  As shown in FIG. 6, a turning speed sensor 31 is provided in the hydraulic circuit according to the second embodiment. The turning speed sensor 31 is a sensor that detects the turning speed of the upper turning body 2, and is attached to, for example, the lower traveling body 1. The detection signal of the turning speed sensor 31 is input to the controller 20 as an electric signal. For example, a gyro sensor is used as the turning speed sensor.

  The specific control performed by the controller 20 is shown in FIG. The differences between the first embodiment and the second embodiment are steps S6 and S7. In the first embodiment, a pressure (Px) set with respect to the pressure of the second hydraulic pump is used as a threshold value for starting the limit control according to the turning pilot pressure. On the other hand, in the second embodiment, Vx, which is a turning speed set with respect to the turning speed of the upper-part turning body 2, is used as a threshold value for starting the limit control according to the turning pilot pressure. As in the case of the first embodiment, the limit control start determination unit 51 sets the threshold value Vx to a larger value as the turning pilot pressure input to the turning control valve 17 increases. Note that the threshold value Vx for starting the limit control may be an arbitrary value determined in advance (preliminarily input to the controller 20) regardless of the magnitude of the turning pilot pressure.

  The limit control start determination unit 51 determines whether the turning speed V of the upper turning body 2 detected by the turning speed sensor 31 has increased to the threshold value Vx (step S7). When V <Vx, that is, when the turning speed V of the upper-part turning body 2 has not increased to the threshold value Vx (YES in step S7), the restriction control start determination unit 51 sets the restriction start flag to “ON” ( Step 8). When V <Vx is not satisfied (NO in step S7), that is, when the swing speed V of the upper swing body 2 is sufficiently fast, the normal control unit 53 of the controller 20 performs the normal control (step S4). ).

  Note that, instead of the turning speed of the upper swing body 2, the swing movement amount of the upper swing body 2 may be used as the threshold value for starting the limit control. In this case, a turning movement amount sensor for detecting the turning movement amount of the upper turning body 2 is required. Note that the gyro sensor can be used as a turning speed sensor or as a turning movement amount sensor.

  The swing speed of the upper swing body 2 and the swing movement amount of the upper swing body 2 are parameters that more directly reflect the movement of the swing motor 11 than the pressure of the second hydraulic pump. Therefore, by using a swing speed set with respect to the swing speed of the upper swing body 2 and a swing movement amount set with respect to the swing movement amount of the upper swing body 2 as the threshold value of the limit control start, Fine control that can more reliably ensure the start of the swing motor can be performed.

(Third embodiment)
FIG. 8 is a diagram illustrating a hydraulic circuit according to a third embodiment mounted on the hydraulic excavator 100. FIG. 9 is a flowchart illustrating a control operation according to the third embodiment. Hereinafter, the third embodiment will be described mainly with respect to differences from the first embodiment.

  The first hydraulic pump pressure sensor 23 and the second hydraulic pump pressure sensor 24 (see FIG. 2) are not arranged in the hydraulic circuit of the third embodiment. That is, in the third embodiment, the first hydraulic pump pressure sensor 23 and the second hydraulic pump pressure sensor 24 are unnecessary. Further, the controller 20 of the third embodiment does not include the restriction control start determination unit 51 and the restriction control continuation determination unit 52.

  Specific control performed by the controller 20 will be described with reference to a flowchart shown in FIG.

  The controller 20 takes in signals and the like from the sensors 25, 26A, 26B (step S1). The controller 20 determines whether there is a boom raising operation signal and a turning operation signal (step S2). The determination of the presence or absence of the boom raising operation signal and the turning operation signal is made using signals from the boom raising pilot pressure sensor 25 and the turning pilot pressure sensor 26A (or 26B) taken into the controller 20. If there is no signal in either the boom raising operation signal or the turning operation signal (NO in step S2), the normal control unit 53 of the controller 20 performs the normal control (step S3).

  On the other hand, if there are both the boom raising operation signal and the turning operation signal (YES in step S2), controller 20 sets instruction current value I for performing the limit control and time T for performing the limit control ( Step S4). The command current value I is a current value smaller than that in the case of the normal control for limiting the distribution supply amount of the working oil from the second hydraulic pump 14 to the boom cylinder 8, and is supplied from the controller 20 to the solenoid 19A. This is the instruction current value of the exciting current. The command current value I is set to a current value that can ensure the start of the turning motor 11 even on a slope. It is preferable that the command current value I is set to a smaller value as the turning pilot pressure input to the turning control valve 17 is larger. This is because the supply of hydraulic oil to the swing motor 11 is given higher priority. Further, it is preferable that the command current value I is set so that the pressure of the second hydraulic pump 14 becomes 30 MPa or more in the relationship between the boom raising pilot pressure and the turning pilot pressure.

  The restriction control unit 54 of the controller 20 performs the restriction control by driving the pilot pressure control valve 19 with the command current value I set in step S4 during the time T set in step S4 (steps S5 and S6). ). After the time T set in step S4 has elapsed, the normal control unit 53 of the controller 20 performs the normal control (step S3). According to the third embodiment, there is an advantage that the number of necessary sensors is small.

  Although the embodiments of the present invention have been described above, various changes can be made within a range that can be assumed by those skilled in the art.

  The hydraulic actuator that operates in response to the supply of the hydraulic oil discharged from the first hydraulic pump 13 and distributes and supplies the hydraulic oil discharged from the second hydraulic pump 14 is not limited to the boom cylinder 8. The hydraulic actuator may be, for example, the arm cylinder 9 or the bucket cylinder 10. Further, the swing motor 11 and other hydraulic actuators are connected to a common hydraulic pump, and the flow rate of the hydraulic oil supplied to the hydraulic actuator is reduced to the flow rate of the hydraulic oil supplied to the swing motor 11. It can be widely applied to those that have an effect.

1: Lower traveling body 2: Upper revolving superstructure 5: Boom 8: Boom cylinder (hydraulic actuator)
11: swing motor 13: first hydraulic pump 14: second hydraulic pump 17: swing control valve 18: distribution valve 20: controller 21: boom remote control valve (actuator actuator)
51: Limit control start determining unit 52: Limit control continuation determining unit 53: Normal control unit 54: Limit control unit 100: Hydraulic shovel (swing hydraulic working machine)

Claims (6)

A swing hydraulic working machine,
An undercarriage,
An upper revolving structure mounted on the lower traveling structure,
A first hydraulic pump mounted on the upper rotating body, and a second hydraulic pump;
A hydraulic actuator that operates by receiving a supply of hydraulic oil discharged by the first hydraulic pump;
A swing motor that swings the upper swing body, the swing motor being operated by receiving a supply of hydraulic oil discharged from the second hydraulic pump;
An actuator operation device provided with an actuator operation for commanding the operation of the hydraulic actuator,
A swing control valve interposed between the second hydraulic pump and the swing motor, for supplying and discharging hydraulic oil discharged by the second hydraulic pump to the swing motor;
A distribution valve interposed between the second hydraulic pump and the turning control valve, for distributing hydraulic oil discharged by the second hydraulic pump to the turning motor and the hydraulic actuator;
A controller for controlling the distribution valve;
With
The controller is
A normal control unit that performs a normal control of changing an opening degree of the distribution valve so as to distribute and supply a basic combined flow rate of hydraulic oil from the second hydraulic pump to the hydraulic actuator according to an operation amount of the actuator operation device; ,
A restriction control unit that performs restriction control that changes an opening degree of the distribution valve so as to restrict a distribution supply amount of hydraulic oil from the second hydraulic pump to the hydraulic actuator,
At the time of the combined operation of the operation of the hydraulic actuator and the operation of the swing motor, the controller sets the pressure of the second hydraulic pump, the swing amount of the upper swing body, or the swing speed of the upper swing body to a predetermined value. If it does not rise to the threshold, perform the limit control, otherwise perform the normal control, or perform a set time, perform the limit control, perform the normal control after the set time,
Swiveling hydraulic working machine. The swiveling hydraulic working machine according to claim 1,
The controller may include a restriction control start determining unit that determines whether the pressure of the second hydraulic pump, the amount of swing movement of the upper swing body, or the swing speed of the upper swing body has increased to a predetermined threshold. Have
The controller determines in the restriction control start determination unit that the pressure of the second hydraulic pump, the amount of swing movement of the upper swing body, or the swing speed of the upper swing body has not increased to a predetermined threshold. If the limit control is performed, if not, perform the normal control,
Swiveling hydraulic working machine. The swiveling hydraulic working machine according to claim 2,
The limiting control start determination unit sets the predetermined threshold to a larger value as the turning pilot pressure input to the turning control valve is larger,
Swiveling hydraulic working machine. The swiveling hydraulic working machine according to claim 2 or 3,
The controller has a limit control continuation determination unit that determines whether the swing motor has entered an operation stable state after startup.
The controller performs the limit control when the operation of the swing motor is not determined to be stable by the limit control continuation determination unit, and performs the normal control when the operation of the swing motor is determined to be stable,
Swiveling hydraulic working machine. The swiveling hydraulic working machine according to claim 4,
The limit control continuation determination unit determines whether or not the swing motor has entered an operation stable state after startup based on the magnitude of the pressure of the second hydraulic pump.
Swiveling hydraulic working machine. The swiveling hydraulic working machine according to claim 5,
When the pressure of the second hydraulic pump drops to a set pressure set based on the magnitude of the pressure of the first hydraulic pump, the limit control continuation determining unit determines that the operation of the swing motor has stabilized. ,
Swiveling hydraulic working machine.

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