JP6581444B2 - Work machine - Google Patents

Description

  The present invention relates to a work machine, and more particularly to a work machine including a control device for a hydraulic drive device that drives a hydraulic actuator.

  In the field of work machines such as hydraulic excavators, work machines using a hydraulic circuit (hereinafter referred to as an open circuit) for returning return oil from a hydraulic actuator such as a hydraulic cylinder or a hydraulic motor to a tank are mainly used. In order to reduce the consumption rate, the number of throttle elements in the hydraulic circuit of the hydraulic actuator is reduced, and the drive speed of the hydraulic actuator is controlled by controlling the discharge flow rate from the unidirectional hydraulic pump, and the return oil from the hydraulic actuator is discharged to the tank. A hydraulic circuit is disclosed in Patent Document 1. (Such hydraulic circuit is hereinafter referred to as “open circuit pump direct control circuit”).

  In addition, the double tilt hydraulic pump and the hydraulic actuator are connected in a closed circuit, and the drive speed of the hydraulic actuator is controlled by controlling the discharge flow rate from the hydraulic pump, and the return oil from the hydraulic actuator is transferred to the double tilt hydraulic pump. Development of a closed circuit to return is underway. A hydraulic circuit in which an open circuit pump is additionally provided in such a closed circuit is disclosed in Patent Document 2. (Such hydraulic circuit is hereinafter referred to as “open circuit / closed circuit pump direct control circuit”).

  The above-described open circuit pump direct control circuit and open circuit / closed circuit pump direct control circuit are configured by directly connecting a hydraulic pump, which is a single tilt pump or both tilt pumps, and a hydraulic actuator through a flow path. In such a configuration, the magnitude of the discharge flow rate of the hydraulic pump is limited in terms of mountability and cost, so that the hydraulic actuator cannot be driven at a sufficient speed if the discharge flow rate of the hydraulic pump is insufficient. Arise. For this reason, there is a configuration in which a flow path switching circuit is provided on a flow path connecting a hydraulic pump and a hydraulic actuator, and hydraulic oil discharged from a plurality of hydraulic pumps is selectively merged to drive the hydraulic actuator at high speed. 1 and 2.

International Publication No. 2011/031851 JP 2013-245787 A

  The flow path switching circuits described in Patent Documents 1 and 2 are composed of a plurality of switching valves, and are controlled by an electrical control signal via a control signal line from a control device. Since the flow path switching circuit realizes a combination of flow paths connecting all the hydraulic pumps and the hydraulic actuators with a switching valve, the number of switching valves that are electronically controlled is larger than that of a normal hydraulic excavator. For this reason, the number of long control signal lines necessary for control of the switching valve increases, and there is a problem in that the cost of the control signal lines is increased and the reliability is lowered.

  In order to shorten the length of the control signal line, there is a method in which the control devices are arranged in a distributed manner, and control devices for device control (hereinafter referred to as “device control devices”) are installed near the switching valve to be controlled. Conceivable. However, even in this case, if the device control device fails, all the flow path switching circuits become inoperable and pressure oil from the hydraulic pump cannot be supplied to the hydraulic actuator. As a result, the hydraulic excavator becomes inoperable and the operating rate of the product decreases.

  The present invention has been made based on the above-described matters, and an object of the present invention is to provide an apparatus control device in an open circuit / closed circuit pump direct control circuit having a flow path switching circuit or an open circuit pump direct control circuit. It is an object of the present invention to provide a work machine with a high operating rate that can prevent operation of a hydraulic excavator at the time of failure and can continue work.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, a plurality of hydraulic pumps, a plurality of hydraulic actuators, and the plurality of hydraulic pumps and the plurality of hydraulic actuators are connected. operations and a plurality of hydraulic circuits consists of the flow path, and a plurality of switching valves for selectively connecting each of the plurality of hydraulic pumps to one of said plurality of hydraulic actuators, a plurality of hydraulic actuators In the work machine having an operation device for performing the operation, based on a preset relationship among the operation command value of the operation device, the plurality of hydraulic pumps, the plurality of hydraulic actuators, and the plurality of switching valves, the operation According to the operation command value of the apparatus, a switching valve to be in a circulation state is selected from the plurality of switching valves, and the selected switching valve is in a circulation state and is not selected. And the channel selection section Tsu has switching valve to set the channel switching circuit control signal so that the cut-off state, the signal for transmitting the channel switching circuit control signal set by the channel selection unit via the communication line A high-order control device having a transmission unit, and provided for each switching valve connected to the same hydraulic pump among the plurality of switching valves, and connected to the plurality of switching valves by a control signal line, the high-order control device And a plurality of device control devices connected via the communication line, wherein the device control device receives the flow path switching circuit control signal from the host control device via the communication line. And a flow path control unit that generates a command signal for driving the plurality of switching valves based on the flow path switching circuit control signal, and outputs the command signal through the control signal line. whether the plurality of device control apparatus is malfunctioning Further comprising determining failure determination section, the channel selection section, when the failure determination section determines that the failure of one device control apparatus among the plurality of device control apparatus, among the plurality of hydraulic actuators In place of the one switching valve, another device control different from the one device control device is applied to the hydraulic actuator that has been supplied with hydraulic oil via the one switching valve connected to the one device control device. The flow path switching circuit control signal is reset so that hydraulic fluid is supplied through another switching valve connected to the apparatus .

  According to the present invention, in a work machine including a plurality of hydraulic circuits configured by connecting a hydraulic pump and a hydraulic actuator through flow paths, even if any device control device fails, some of the flow path switching circuits It is possible to provide a work machine with a high operating rate that can continue work only by stopping the operation.

1 is a side view showing a hydraulic excavator that is a first embodiment of a work machine of the present invention. It is the schematic which shows the hydraulic drive which comprises 1st Embodiment of the working machine of this invention. It is the schematic which shows the hydraulic drive device which comprises 2nd Embodiment of the working machine of this invention. It is the schematic which shows the hydraulic drive device which comprises 3rd Embodiment of the working machine of this invention. It is the schematic which shows the hydraulic drive unit which comprises 4th Embodiment of the working machine of this invention.

  Embodiments of a working machine according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing a hydraulic excavator which is a first embodiment of the working machine of the present invention, and FIG. 2 is a schematic diagram showing a hydraulic drive device constituting the first embodiment of the working machine of the present invention. is there.

  In the open circuit pump direct control circuit having the flow path switching circuit of the prior art, the flow path switching circuit becomes inoperable when the control device that drives the flow path switching circuit fails. Cannot be supplied to the hydraulic actuator, and the excavator becomes inoperable. Therefore, in the first embodiment of the work machine of the present invention, control commands to the hydraulic circuit having a plurality of open circuit pump direct control circuits and the flow path switching circuit according to the operation amount of the operator's operating device are sent. A host control device that performs calculation and transmission and a plurality of device control devices provided for each open circuit pump direct control circuit are provided, and each device control device and the host control device are connected by a communication line. As a result, even if one of the device control devices fails and stops, only a part of the flow path switching circuits stops, and the pressure oil can be supplied to the hydraulic actuator by another device control device. As a result, it is possible to provide a hydraulic excavator with a high operating rate that can continue work without stopping operation.

  In FIG. 1, a hydraulic excavator 100 includes a lower traveling body 103 provided with crawler type traveling devices 8 a and 8 b on both sides in the left-right direction, and an upper revolving body as a main body pivotably mounted on the lower traveling body 103. 102. A cab 101 is provided on the upper swing body 102 as an operation room in which an operator gets on. The lower traveling body 103 and the upper swing body 102 are turnable via the swing hydraulic motor 7.

  On the front side of the upper swing body 102, for example, a base end portion of a front work machine 104 that is an operation device for performing excavation work or the like is rotatably attached. Here, the front side refers to a direction (left direction in FIG. 1) in which the operator boarding the cab 101 faces.

  The front work machine 104 includes a boom 2 having a base end portion connected to the front side of the upper swing body 102 so as to be able to move up and down. The boom 2 operates via a boom cylinder 1 which is a single rod hydraulic cylinder driven by hydraulic oil (pressure oil) as a supplied fluid. In the boom cylinder 1, the tip of the boom rod 1 b is connected to the upper swing body 102, and the base end of the boom head 1 a is connected to the boom 2.

  The base end portion of the arm 4 is connected to the tip end portion of the boom 2 so as to move up and down. The arm 4 operates via an arm cylinder 3 that is a single rod hydraulic cylinder. In the arm cylinder 3, the tip of the arm rod 3 b is connected to the arm 4, and the arm head 3 a of the arm cylinder 3 is connected to the boom 2.

  The base end portion of the bucket 6 is connected to the tip end portion of the arm 4 so as to be able to move up and down. The bucket 6 operates via a bucket cylinder 5 that is a single rod hydraulic cylinder as a hydraulic actuator that is driven by supplied hydraulic oil. In the bucket cylinder 5, the tip end of the bucket rod 5 b is connected to the bucket 6, and the base end of the bucket head 5 a of the bucket cylinder 5 is connected to the arm 4.

Next, the system configuration of the hydraulic drive apparatus in the schematic diagram shown in FIG. 2 will be described.
In FIG. 2, the drive shaft of the engine 9 as a power source is connected to a power transmission device 10 that distributes power. The power transmission device 10 is connected to a first piece tilt pump 11 and a second piece tilt pump 12 which are open circuit pumps.

  The first half-tilt pump 11 and the second half-tilt pump 12 each have a pair of input / output ports as flow rate adjusting means, and a tilt displacement of the swash plate to adjust the displacement of the pump. Regulators 11a and 12a to be operated are provided. The regulators 11a and 12a control the discharge flow rates of the first half tilt pump 11 and the second half tilt pump 12 according to the pump discharge flow rate command value received from the host controller 33 via the communication line.

  The discharge port of the first one-side tilting pump 11 is connected to switching valves 14 and 15 as a channel switching circuit via a channel 20. The switching valves 14 and 15 are controlled in the flow-through direction and switching direction of the flow path by a signal from the first device control device 18 via the control signal line. The suction port of the first one-side tilt pump 11 is connected to the switching valves 14 and 15 and the tank 32 via the flow path 22.

  The switching valve 14 is connected to the boom cylinder 1 via the flow paths 21 and 23, and when the switching valve 14 is in a flow state, the first single tilt pump 11 is connected to the boom cylinder 1 and the flow paths 20, 21, and 23. , 22 are connected.

  The switching valve 15 is connected to the arm cylinder 3 via the flow paths 28, 29, 25, 27, and when the switching valve 15 is in a flow state, the first unidirectional pump 11 is connected to the arm cylinder 3 and the flow path 20. , 22, 28, 29, 25, 27.

  Similarly, the discharge port of the second decanting pump 12 is connected to switching valves 16 and 17 as a flow path switching circuit via a flow path 24. The switching valves 16 and 17 are controlled by the signal from the second device control device 19 through the control signal line to control the flow and switching direction of the flow path. The suction port of the second decanter pump 12 is connected to the switching valves 16 and 17 and the tank 32 via the flow path 26.

  The switching valve 16 is connected to the boom cylinder 1 via the flow paths 30, 31, 21, 23, and when the switching valve 16 is in a flow state, the second unidirectional pump 12 is connected to the boom cylinder 1 and the flow path 24. , 26, 30, 31, 21, 23.

  The switching valve 17 is connected to the arm cylinder 3 via the flow paths 25 and 27, and when the switching valve 17 is in a flow state, the second one-side tilt pump 12 is connected to the arm cylinder 3 and the flow paths 24, 25 and 27. , 26 are connected.

  The hydraulic drive apparatus according to the present embodiment includes operation lever type operation devices 34 a and 34 b connected to the host control device 33 as an operation system. The up / down operation of the operating device 34a corresponds to the operation of the boom cylinder 1, the left / right operation of the operating device 34a corresponds to the operation of the swing hydraulic motor 7, and the up / down operation of the operating device 34b corresponds to the operation of the arm cylinder 3. The left / right operation of the device 34 b corresponds to the operation of the bucket cylinder 5. The correspondence between the operation direction of the operation devices 34a and 34b and the operation of each hydraulic actuator may be another method.

  The host control device 33 includes a flow path selection unit 33a, a failure determination unit 33b, and a signal transmission unit 33c. The host control device 33 performs arithmetic processing on the operation command value input from the operation devices 34a and 34b via the control signal line, and outputs the control signal after the arithmetic processing to the first / second device control devices 18 and 19 and the regulator 11a. , 12a via a communication line to control them.

  The flow path selection unit 33a is a pump that is a control amount of the first / second one-side tilt pumps 11 and 12 and the switching valves 14 to 17 based on an operation command value when the operator operates the operation devices 34a and 34a. The discharge flow rate command value and the flow path switching circuit control signal are calculated. The calculation method is, for example, based on a table in which the relationship between the operation command value, the first / second decanter pumps 11 and 12 to be operated, and the switching valves 14 to 17 is set in advance, and the pump discharge flow rate command value and flow rate. A path switching circuit control signal is determined.

  The failure determination unit 33b detects malfunction and stop due to failure of the device control devices 18 and 19 connected to the host control device 33 via a communication line. For example, the failure detection means of the first / second device control devices 18 and 19 is configured to transmit an operation state signal from the first / second device control devices 18 and 19 to the host control device 33 at regular time intervals. The failure determination unit 33b may determine whether or not the operation state signal has been received.

  When the host control device 33 can receive the operation state signal, the failure determination unit 33b determines that the first / second device control devices 18 and 19 are in a normal operation state. When the host control device 33 cannot receive the operation state signal, the failure determination unit 33b determines that any one or all of the first / second device control devices 18 and 19 are in a failure state. Specifically, a case where any or all of the first / second device control devices 18 and 19 are stopped, a case where a communication line is disconnected, or the like can be considered.

  The signal transmission unit 33c controls the flow path switching circuit which is the flow rate switching direction of the pump discharge flow rate command values of the first / second half tilt pumps 11 and 12 calculated by the flow path selection unit 33a and the switching valves 14 to 17. The signal is transmitted to the regulators 11a and 12a and the first / second device control devices 18 and 19 via the communication line.

  The first device control device 18 includes a signal receiving unit 18a and a flow channel control unit 18b, and the second device control device 19 includes a signal receiving unit 19a and a flow channel control unit 19b.

  In the first device controller 18, the signal receiver 18a receives the flow path switching circuit control signal from the host controller 33 via the communication line. The flow path control unit 18b controls the switching valves 14 and 15 via the control signal line based on the received flow path switching circuit control signal, and between the flow path 20 and the flow paths 21, 23, 28, and 29. , Put in a shut-off state or a distribution state. Similarly, the 2nd apparatus control apparatus 19 controls the switching valves 16 and 17 and makes between the flow path 24 and the flow paths 25, 27, 30, and 31 the interruption | blocking state or a distribution state.

A series of operations for driving the hydraulic actuator in the hydraulic drive apparatus configured as described above will be described.
First, the stop state of the boom cylinder 1 and the arm cylinder 3 will be described.

  When the operation devices 34a and 34b are not operated, the flow path selection unit 33a of the host control device 33 receives each operation amount (zero operation amount) of the operation devices 34a and 34b via the control signal line, and is set in advance, for example. Based on the table, the pump discharge flow rate command value of the first / second decanter pumps 11 and 12 corresponding to the operation amount is determined to be 0, and the flow in the flow path switching direction of the switching valves 14 to 17 is determined. All the path switching circuit control signals are determined to be cut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 11a and 12a via the communication line, and the regulators 11a and 12a are based on the received pump discharge flow rate command value. 11 and 12 are controlled.

  The signal transmission unit 33c transmits the flow path switching circuit control signal to the first / second device control devices 18 and 19 via the communication line, and the signal reception unit of the first / second device control devices 18 and 19 18a and 19a receive the flow path switching circuit control signal. The flow path control unit 18b controls the switching valves 14 and 15 to be shut off based on the received flow path switching circuit control signal. Moreover, the flow path control unit 19b controls the switching valves 16 and 17 to be in a shut-off state based on the received flow path switching circuit control signal.

  Since the discharge flow rates of the first / second half-tilt pumps 11 and 12 are 0 and the switching valves 14 to 17 are also controlled to be shut off, the boom cylinder 1 and the arm cylinder 3 are stopped.

  Next, the case where the boom cylinder 1 is extended will be described.

When the operation device 34a is operated in the direction in which the boom cylinder 1 is advanced and the operation device 34b is not operated, the flow path selection unit 33a of the host control device 33 operates each operation device 34a, 34b via the control signal line. For example, based on a preset table, the pump discharge flow rate command value of the first single tilt pump 11 is set to a positive value corresponding to the operation amount, and the pump of the second single tilt pump 12 is received. The discharge flow rate command value is determined to be 0.
Further, the flow path switching circuit control signal of the switching valve 14 is determined so that the flow path 20 and the flow path 21 are in a flow state, and all the flow path switching circuit control signals of the switching valves 15 to 17 are determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 11a and 12a via the communication line, and the regulators 11a and 12a discharge the first single tilt pump 11 based on the received pump discharge flow rate command value. The flow rate is set to a certain positive value, and control is performed so that the hydraulic oil is discharged to the flow path 20 side, and the discharge flow rate of the second one-side tilt pump 12 is controlled to zero.

  The signal transmission unit 33c transmits the flow path switching circuit control signal to the first / second device control devices 18 and 19 via the communication line, and the signal reception unit of the first / second device control devices 18 and 19 18a and 19a receive the flow path switching circuit control signal, respectively. Based on the received flow path switching circuit control signal, the flow path control unit 18b controls the switching valve 14 so that the flow path 20 and the flow path 21 are in a flow state, and controls the switching valve 15 in a cutoff state. Further, the flow path control unit 19b controls the switching valves 16 and 17 to be in a shut-off state based on the received flow path switching circuit control signal.

  Since the first single tilt pump 11 discharges the hydraulic oil and the switching valve 14 is in the flow state, the hydraulic oil discharged by the first single tilt pump 11 is the flow path 20, the switching valve 14, and the flow path 21. And flows into the oil chamber on the boom head 1a side, and the boom cylinder 1 extends. When the boom cylinder 1 extends, the hydraulic oil flows out from the oil chamber on the boom rod 1 b side to the tank 32 and the first one-side tilt pump 11 through the flow path 23, the switching valve 14, and the flow path 22. At this time, the arm cylinder 3 is stopped.

  Next, the case where the boom cylinder 1 is extended when the first device control device 18 fails and stops will be described.

  When the operation device 34a is operated in the direction in which the boom cylinder 1 is advanced and the operation device 34b is not operated, the flow path selection unit 33a of the host control device 33 operates each operation device 34a, 34b via the control signal line. For example, based on a preset table, the pump discharge flow rate command value of the first single tilt pump 11 is set to a positive value corresponding to the operation amount, and the pump of the second single tilt pump 12 is received. The discharge flow rate command value is determined to be 0. Further, the flow path switching circuit control signal of the switching valve 14 is determined so that the flow path 20 and the flow path 21 are in a flow state, and all the flow path switching circuit control signals of the switching valves 15 to 17 are determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. For example, when the operation state signal from the first device control device 18 via the communication line is sent to the failure determination unit 33b, the failure state determination method determines that the operation state is normal, and for a certain period of time, If no signal is sent, the first device control device 18 determines that a failure has occurred. When the first device control device 18 fails and stops, the failure determination unit 33b determines that the first device control device 18 is in a failure state.

  The failure determination unit 33b that has determined that the first device control device 18 is in the failure state sets the pump discharge flow rate command value of the first unidirectional pump 11 according to the operation amount of the operating device 34a to 0, and the second unidirectional pump. The pump discharge flow rate command value of 12 is reset to a certain positive value. Further, the flow path switching circuit control signal of the switching valve 16 is reset so that the flow path 24 and the flow path 31 are in the flow state, and all the flow path switching circuit control signals of the switching valves 14, 15, and 17 are shut off and re-set. Set.

  The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 11a and 12a via the communication line, and the regulators 11a and 12a discharge the second single tilt pump 12 based on the received pump discharge flow rate command value. The flow rate is set to a positive value, and control is performed so that the hydraulic oil is discharged to the flow path 24 side, and the discharge flow rate of the first one-side tilt pump 11 is controlled to zero. Moreover, the signal transmission part 33c transmits a flow-path switching circuit control signal to the 1st / 2nd apparatus control apparatuses 18 and 19 via a communication line.

  The signal receiving units 18a and 19a of the first / second device control devices 18 and 19 receive the flow path switching circuit control signal via the communication line. Based on the received flow path switching circuit control signal, the flow path control unit 19b controls the switching valve 16 so that the flow path 24 and the flow path 31 are in a flow state and the switching valve 17 is in a shut-off state. At this time, since the flow path control unit 18b is out of order, it cannot receive the flow path switching circuit control signal, and the switching valves 14 and 15 are not controlled, and are in the initial cutoff state.

  Since the second piece tilting pump 12 discharges the working oil and the switching valve 16 is in a flow state, the working oil discharged by the second piece tilting pump 12 flows through the flow path 24, the switching valve 16, and the flow path 31. , 21 flows into the oil chamber on the boom head 1a side, and the boom cylinder 1 extends. When the boom cylinder 1 extends, the hydraulic oil flows from the oil chamber on the boom rod 1b side to the tank 32 and the second one-side tilt pump 12 through the flow paths 23, 30, the switching valve 16, and the flow path 26. At this time, the arm cylinder 3 is stopped.

  In the schematic diagram shown in FIG. 2, for example, the functions of the first device control device 18 and the second device control device 19 are configured by a single control device, and the switching valve 14 is connected from this control device via a control signal line. When -18 are connected, if this control device fails, the directional control valves 14-18 cannot be controlled, and the directional control valves 14-18 are all in an initial cut-off state. Therefore, the hydraulic oil discharged from the first / second half-tilt pumps 11 and 12 cannot flow into either the boom cylinder 1 or the arm cylinder 3, and the boom cylinder 1 and the arm cylinder 3 are stopped. The excavator becomes inoperable.

  In the present embodiment, when any of the first / second device control devices 18 and 19 fails and stops, several of the switching valves 14 to 17 that are flow path switching circuits become uncontrollable. However, by using a controllable device control device and a switching valve, the discharge hydraulic fluid of any of the first / second half-tilt pumps 11 and 12 is supplied to a boom cylinder 1 or an arm that is a target hydraulic cylinder. It can flow into the cylinder 3. Therefore, a hydraulic excavator with a high operating rate that can continue the operation without stopping the operation even if any one of the device control devices breaks down can be provided.

  According to the above-described first embodiment of the work machine of the present invention, in the work machine 100 including a plurality of hydraulic circuits configured by connecting the hydraulic pumps 11 and 12 and the hydraulic actuators 1 and 3 through a flow path, Even if any one of the device control devices 18 and 19 breaks down, it is possible to provide a work machine with a high operating rate that can continue work only by stopping only a part of the flow path switching circuits.

  Further, according to the first embodiment of the working machine of the present invention described above, for example, in the hydraulic excavator provided with the open circuit pump direct control circuit, one of the device control devices 18 and 19 fails and stops. However, only a part of the flow path switching circuits are stopped, and it is not necessary to stop the hydraulic excavator. Therefore, it is possible to provide a hydraulic excavator with a high operating rate.

  In the present embodiment, the hydraulic drive device for the boom cylinder 1 and the arm cylinder 3 has been described as an example, but the present invention is not limited to this. It may be applied to any open circuit of a boom, arm, bucket, or hydraulic motor, and the type of hydraulic actuator is not limited.

  Moreover, in this Embodiment, although the pattern which drives the boom cylinder 1 when the 1st apparatus control apparatus 18 failed was described, it does not restrict to this. Similarly, when the arm cylinder 3 is extended or retracted, the discharge of the channel switching circuit connected to the device controller that operates normally and the unidirectional pump connected to the controllable channel switching circuit through the channel The arm cylinder 3 can be driven by controlling the flow rate.

  In addition, when the second device control device 19 fails and stops and the first device control device 18 is operating, the flow path switching circuit connected to the first device control device 18 operating normally and the control The arm cylinder 3 can be driven by controlling the discharge flow rate of the first one-side tilting pump 11 connected to the possible flow path switching circuit through the flow path.

  Hereinafter, a second embodiment of the work machine of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing a hydraulic drive device constituting a second embodiment of the work machine of the present invention. In FIG. 3, the same reference numerals as those shown in FIGS. 1 and 2 are the same parts, and detailed description thereof is omitted.

  In the present embodiment, the first and second pieces are connected to a circuit in which the boom cylinder 1 and the arm cylinder 3 as hydraulic actuators and the first and second both tilt pumps 35 and 36 are connected by a hydraulic closed circuit, respectively. Direct control of a plurality of open circuit / closed circuit pumps that connect the tilt pumps 11 and 12 to the flow path on the cylinder head side of the hydraulic closed circuit and drive the hydraulic actuator by linking both the tilt pump and the single tilt pump. A circuit is provided, and a plurality of device control devices are provided for each open circuit / closed circuit pump direct control circuit.

The second embodiment of the work machine according to the present invention shown in FIG. 3 is configured with almost the same equipment as the first embodiment, but the following configuration is different.
In the present embodiment, there are provided circuits in which the boom cylinder 1 and the arm cylinder 3 are connected as hydraulic actuators to the first and second both tilting pumps 35 and 36, respectively, in a hydraulic closed circuit. The first and second both tilting pumps 35 and 36 are connected to the power transmission device 10 and each has a pair of tilting swash plate mechanisms having a pair of input / output ports as flow rate adjusting means, and the tilt angle of the swash plate. Regulators 35a and 36a for adjusting and adjusting the displacement of the pump are provided. The regulators 35a and 36a control the discharge flow rates of the first and second both tilting pumps 35 and 36 according to the pump discharge flow rate command value received from the host controller 33 via the communication line.

  As the flow path switching circuit, switching valves 37, 38, 39, 40, 41, 43 are provided. The switching valve 37 is connected to the flow paths 20 to 23, and the switching valve 38 is connected to the flow paths 20, 22, 28, and 29. The switching valves 37 and 38 are controlled to flow / shut off the flow path by a signal from the first device control device 18 via the control signal line, and are controlled to be shut off when there is no signal. Further, the switching valve 39 is connected to the flow paths 24, 26, 30 and 31, and the switching valve 40 is connected to the flow paths 24 to 27. The switching valves 39 and 40 are controlled to flow / shut off the flow path by a signal from the second device control device 19 via the control signal line, and are controlled to be shut off when there is no signal.

  The switching valve 37 is connected to the boom cylinder 1 via the flow paths 21 and 23. When the switching valve 37 is in a flow state, the first double tilt pump 35 is connected to the boom cylinder 1 and the flow paths 20, 21, 23. , 22 are connected.

  The switching valve 38 is connected to the arm cylinder 3 via the flow paths 28, 29, 25, 27, and when the switching valve 38 is in a flow state, the first double tilt pump 35 is connected to the arm cylinder 3 and the flow path 20. , 22, 28, 29, 25, 27.

  The switching valve 39 is connected to the boom cylinder 1 via the flow paths 30, 31, 21, 23, and when the switching valve 39 enters a flow state, the second bi-directional pump 36 is connected to the boom cylinder 1 and the flow path 24. , 26, 30, 31, 21, 23.

  The switching valve 40 is connected to the arm cylinder 3 via the flow paths 25 and 27, and when the switching valve 40 is in a flow state, the second double tilt pump 36 is connected to the arm cylinder 3 and the flow paths 24, 25, 27. , 26 are connected.

  Further, the discharge port of the first one-side tilt pump 11 is connected to the flow path 20 via the switching valve 41 and the flow path 42. The switching valve 41 is controlled to flow / shut off the flow path by a signal from the first device control device 18 via the control signal line, and is controlled to be shut off when there is no signal. The suction port of the first decanting pump 11 is connected to the tank 32 via a flow path. Similarly, the discharge port of the second piece tilting pump 12 is connected to the flow path 24 via the switching valve 43 and the flow path 44. The switching valve 43 is controlled to flow / shut off the flow path by a signal from the second device control device 19 via the control signal line, and is controlled to be shut off when there is no signal. The suction port of the second decanter pump 12 is connected to the tank 32 through a flow path.

  In the present embodiment, the discharge ports of the first / second decanter pumps 11 and 12 are connected to the flow paths 20 and 24. However, the present invention is not limited to this. 26 may be connected to each other.

  A check valve 45 a and a flushing valve 46 a are connected to the flow path 21 and the flow path 23, and a check valve 45 b and a flushing valve 46 b are connected to the flow path 25 and the flow path 27. When the pressure in the flow paths 21 and 23 drops below the pressure in the tank 32, the check valve 45a sucks the hydraulic oil in the tank 32 into the circuit and prevents circuit cavitation. Similarly, the check valve 45b operates according to the pressure in the flow paths 25 and 27. The flushing valves 46a and 46b connect the flow paths 21 and 23 or the low pressure paths of the flow paths 25 and 27 to the tank 32, and discharge excess hydraulic oil in the closed circuit.

  Moreover, the 1st apparatus control apparatus 18 is connected to switching valve 37,38,41 via the control signal line, and is connected to the high-order control apparatus 33 via the communication line. Similarly, the second device control device 19 is connected to the switching valves 39, 40, and 43 via a control signal line, and is connected to the host control device 33 via a communication line.

Next, a series of operations for driving the hydraulic actuator in the present embodiment will be described.
First, the stop state of the boom cylinder 1 and the arm cylinder 3 will be described.

  When the operation devices 34a and 34b are not operated, the flow path selection unit 33a of the host control device 33 receives each operation amount (zero operation amount) of the operation devices 34a and 34b via the control signal line, and is set in advance, for example. Based on the table, the pump discharge flow rate command values of the first / second bi-directional tilt pumps 35, 36 and the first / second single-tilt pumps 11, 12 corresponding to the operation amount are determined to be 0. The flow path switching circuit control signals that are the flow path switching directions of the switching valves 37 to 41, 43 are all determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 35a, 36a, 11a, and 12a via the communication line, and the regulators 35a, 36a, 11a, and 12a receive the pump discharge flow rate command value based on the received pump discharge flow rate command value. The discharge flow rates of the 1 / second both tilt pumps 35, 36 and the first / second half tilt pumps 11, 12 are controlled.

  The signal transmission unit 33c transmits the flow path switching circuit control signal to the first / second device control devices 18 and 19 via the communication line, and the signal reception unit of the first / second device control devices 18 and 19 18a and 19a receive the flow path switching circuit control signal. The flow path control unit 18b controls the switching valves 37, 38, and 41 to be in a shut-off state based on the received flow path switching circuit control signal. Further, the flow path control unit 19b controls the switching valves 39, 40, and 43 to be in a shut-off state based on the received flow path switching circuit control signal.

  The discharge flow rates of the first / second bi-directional tilt pumps 35, 36 and the first / second half-tilt pumps 11, 12 are 0, and the switching valves 37 to 41, 43 are also controlled to be in the shut-off state. Therefore, the boom cylinder 1 and the arm cylinder 3 are stopped.

  Next, the case where the boom cylinder 1 is extended will be described.

  When the operation device 34a is operated in the direction in which the boom cylinder 1 is advanced and the operation device 34b is not operated, the flow path selection unit 33a of the host control device 33 operates each operation device 34a, 34b via the control signal line. For example, based on a table set in advance, the first one-side tilt is set to a value corresponding to the operation amount for discharging the pump discharge flow rate command value of the first double tilt pump 35 to the flow path 20 side. The pump discharge flow rate command value of the pump 11 is determined to be a certain positive value corresponding to the operation amount, and the pump discharge flow rate command values of the second both-side tilt pump 36 and the second single tilt pump 12 are determined to be 0. The flow path selector 33a determines the flow path switching circuit control signal of the switching valve 37 so that the flow path 20 and the flow path 21 are in a flow state, and the flow path switching circuit control signal of the switching valve 41 is the flow path. 42 and decide to be in a distribution state. Further, all the flow path switching circuit control signals of the switching valves 38 to 40, 43 are determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 35a, 36a, 11a, and 12a via the communication line, and the regulators 35a, 36a, 11a, and 12a receive the pump discharge flow rate command value based on the received pump discharge flow rate command value. The discharge flow rate of the one-bore tilt pump 35 is controlled to be discharged to the flow channel 20 side, the discharge flow rate of the first single tilt pump 11 is set to a certain positive value, and the hydraulic oil is discharged to the flow channel 42 side. Control as follows. Further, the discharge flow rates of the second both-side tilt pump 36 and the second one-side tilt pump 12 are controlled to zero.

  The signal transmission unit 33c transmits the flow path switching circuit control signal to the first / second device control devices 18 and 19 via the communication line, and the signal reception unit of the first / second device control devices 18 and 19 18a and 19a receive the flow path switching circuit control signal, respectively. Based on the received flow path switching circuit control signal, the flow path control unit 18b controls the switching valve 37 so that the flow path 20 and the flow path 21 are in a flow state, and the switching valve 41 is in a flow state with the flow path 42. Thus, the switching valve 38 is controlled to be shut off. Further, the flow path control unit 19b controls the switching valves 39, 40, and 43 to be in a shut-off state based on the received flow path switching circuit control signal.

  Since the first double tilting pump 35 discharges the hydraulic oil to the flow path 20 side and the switching valve 37 is in a flow state, the hydraulic oil discharged by the first double tilting pump 35 is the flow path 20, the switching valve. 37, flows into the oil chamber on the boom head 1a side via the flow path 21. Further, since the first single tilting pump 11 discharges the hydraulic oil to the flow path 42 side and the switching valve 41 is in a circulating state, the hydraulic oil discharged by the first double tilting pump 11 passes through the flow path 42. And then flows into the oil chamber on the boom head 1a side. As a result, the boom cylinder 1 extends. When the boom cylinder 1 extends, hydraulic oil flows from the oil chamber on the boom rod 1 b side into the first double tilt pump 35 through the flow path 23, the switching valve 37, and the flow path 22. At this time, the arm cylinder 3 is stopped.

  Next, the case where the boom cylinder 1 is extended when the first device control device 18 fails and stops will be described.

  When the operation device 34a is operated in the direction in which the boom cylinder 1 is advanced and the operation device 34b is not operated, the flow path selection unit 33a of the host control device 33 operates each operation device 34a, 34b via the control signal line. For example, based on a table set in advance, the first one-side tilt is set to a value corresponding to the operation amount for discharging the pump discharge flow rate command value of the first double tilt pump 35 to the flow path 20 side. The pump discharge flow rate command value of the pump 11 is determined to be a certain positive value corresponding to the operation amount, and the pump discharge flow rate command values of the second both-side tilt pump 36 and the second single tilt pump 12 are determined to be 0. Further, the flow path switching circuit control signal of the switching valve 37 is determined so that the flow path 20 and the flow path 21 are in a flow state, and the flow path switching circuit control signal of the switching valve 41 is set in a flow state with the flow path 42. To decide. Further, all the flow path switching circuit control signals of the switching valves 38 to 40, 43 are determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. For example, when the operation state signal from the first device control device 18 via the communication line is sent to the failure determination unit 33b, the failure state determination method determines that the operation state is normal, and for a certain period of time, If no signal is sent, the first device control device 18 determines that a failure has occurred. When the first device control device 18 fails and stops, the failure determination unit 33b determines that the first device control device 18 is in a failure state.

  The failure determination unit 33b that has determined that the first device control device 18 is in the failure state resets the pump discharge flow rate command values of the first bi-directional tilt pump 35 and the first unidirectional tilt pump 11 to 0, and the second bi-directional gradient. The pump discharge flow rate command value of the inversion pump 36 is reset to a value corresponding to the operation amount discharged to the flow path 24 side, and the pump discharge flow rate command value of the second single tilt pump 12 is reset to a certain positive value corresponding to the operation amount. Set. Further, the flow path switching circuit control signal of the switching valve 39 is reset so that the flow path 24 and the flow path 31 are in a flow state, and the flow path switching circuit control signal of the switching valve 43 is in a flow state with the flow path 44. Then, all the flow path switching circuit control signals of the switching valves 37, 38, 40, and 41 are shut off and reset.

  The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 35a, 36a, 11a, and 12a via the communication line, and the regulators 35a, 36a, 11a, and 12a receive the pump discharge flow rate command value based on the received pump discharge flow rate command value. The discharge flow rate of the two-bore tilt pump 36 is controlled to be discharged to the flow channel 24 side, the discharge flow rate of the second piece tilt pump 12 is set to a positive value, and the hydraulic oil is discharged to the flow channel 44 side. Control as follows. Further, the discharge flow rates of the first double tilt pump 35 and the first single tilt pump 11 are controlled to zero.

  The signal transmission unit 33c transmits the flow path switching circuit control signal to the first / second device control devices 18 and 19 via the communication line, and the signal reception unit of the first / second device control devices 18 and 19 18a and 19a receive the flow path switching circuit control signal, respectively. Based on the received flow path switching circuit control signal, the flow path control unit 19b controls the switching valve 39 so that the flow path 24 and the flow path 31 are in a flow state, and the switching valve 43 is in a flow state with the flow path 44. Thus, the switching valve 40 is controlled to be shut off. On the other hand, the flow path control unit 18b cannot receive a signal because it is out of order, and the switching valves 37, 38, and 41 are not controlled and are in the cutoff state that is the initial state.

  Since the second both-side tilt pump 36 and the second one-side tilt pump 12 discharge the hydraulic oil and the switching valves 39 and 43 are in the flow state, the hydraulic oil discharged by the second both-side tilt pump 36 flows. The hydraulic fluid discharged from the second decanting pump 12 through the path 24, the switching valve 39, and the flow paths 31 and 21 flows into the oil chamber on the boom head 1a side via the switching valve 43 and the flow path 44. The boom cylinder 1 extends. When the boom cylinder 1 extends, hydraulic oil flows from the oil chamber on the boom rod 1 b side into the second both-side tilt pump 36 through the flow paths 23, 30, the switching valve 39, and the flow path 26. At this time, the arm cylinder 3 is stopped.

  By the way, in the schematic diagram shown in FIG. 3, for example, the functions of the first device control device 18 and the second device control device 19 are constituted by one control device, and the switching valve 37 is connected from this control device via a control signal line. If the control device breaks down, the switching valves 37 to 41 and 43 cannot be controlled, and the switching valves 37 to 41 and 43 are all in the shut-off state, which is the initial state. It becomes. Therefore, the hydraulic oil discharged from the first / second bi-directional tilt pumps 35, 36 and the first / second single-side tilt pumps 11, 12 can flow into either the boom cylinder 1 or the arm cylinder 3. Therefore, the boom cylinder 1 and the arm cylinder 3 are stopped, and the hydraulic excavator becomes inoperable.

  In the present embodiment, since the device control device is provided for each open circuit / closed circuit pump direct control circuit, if any of the first / second device control devices 18, 19 fails and stops, the flow path switching circuit Some of the switching valves 37 to 41 and 43 become uncontrollable. However, the discharge hydraulic fluid of either the first / second bi-directional tilting pumps 35, 36 and the first / second single-side tilting pumps 11, 12 is controlled using a controllable device control device and a switching valve. The boom cylinder 1 or the arm cylinder 3 which is a target hydraulic cylinder can be made to flow. Therefore, a hydraulic excavator with a high operating rate that can continue the operation without stopping the operation even if any one of the device control devices breaks down can be provided.

  Further, in the present embodiment, the flow path switching circuit constituted by the switching valves 37, 38, 41 connected to the first one-side tilting pump 11 interlocked with the first both-side tilting pump 35 is the same first. The flow path switching circuit constituted by the switching valves 39, 40, 43 controlled by the device control device 18 and connected to the second one-side tilting pump 12 interlocked with the second both-side tilting pump 36 is the same second device. By controlling with the control apparatus 19, the malfunction of the hydraulic actuator at the time of failure of an apparatus control apparatus can be suppressed.

  For example, in the schematic diagram shown in FIG. 3, in the closed circuit / open circuit pump direct control circuit, the ratio of the discharge flow rates of the first double tilt pump 35 and the first single tilt pump 11 is determined by the pressure receiving area of the connected hydraulic cylinder. By matching the ratio, the input / output flow rate difference between the cylinder head and cylinder rod of the hydraulic cylinder is absorbed to improve the operability of the hydraulic cylinder. In this situation, assuming that the switching valves 37 and 38 and the switching valve 41 are controlled by different device control devices, even if the device control device on the switching valve 41 side fails, the switching valves 37 and 38 are controlled. Since it is possible, the first double tilting pump 35 can discharge the hydraulic oil and drive the boom cylinder 1, but the switching valve 41 cannot be controlled. As a result, the hydraulic oil of the first single tilt pump 11 cannot be joined to the first both tilt pump 35 side. As a result, the first both-side tilt pump 35 cannot absorb the input / output flow rate difference according to the pressure receiving area ratio of the hydraulic cylinder, the behavior of the hydraulic cylinder becomes unstable, and the operability is lowered.

  In the present embodiment, when the first device control device 18 fails and stops, the switching valves 37, 38, and 41 are cut off, and the boom is driven by the second both-side tilt pump 36 and the second one-side tilt pump 12. Since the cylinder 1 can be driven, the second both-side tilt pump 36 and the second one-side tilt pump 12 can absorb the input / output flow rate difference that matches the pressure receiving area ratio of the boom cylinder 1. As a result, the operability of the hydraulic excavator does not deteriorate even if the first device control device 18 breaks down.

  According to the second embodiment of the work machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  Further, according to the second embodiment of the working machine of the present invention described above, the device control device is provided for each open circuit / closed circuit pump direct control circuit. The operation can be suppressed.

  In the present embodiment, the hydraulic drive device for the boom cylinder 1 and the arm cylinder 3 has been described as an example, but the present invention is not limited to this. It may be applied to any open circuit of a boom, arm, bucket, or hydraulic motor, and the type of hydraulic actuator is not limited.

  Moreover, in this Embodiment, although the pattern which drives the boom cylinder 1 when the 1st apparatus control apparatus 18 failed was described, it does not restrict to this. Similarly, when the arm cylinder 3 is extended and retracted, a flow path switching circuit connected to a normally operating device control device, a bi-inclination pump connected to a controllable flow path switching circuit by a flow path, and a piece The arm cylinder 3 can be driven by controlling the discharge flow rate of the tilt pump.

  In addition, when the second device control device 19 fails and stops and the first device control device 18 is operating, the flow path switching circuit connected to the first device control device 18 operating normally and the control The arm cylinder 3 can be driven by controlling the discharge flow rates of the first both-side tilt pump 35 and the first one-side tilt pump 11 connected to the possible flow path switching circuit through the flow path.

  Hereinafter, a third embodiment of the work machine of the present invention will be described with reference to the drawings. FIG. 4 is a schematic view showing a hydraulic drive device constituting a third embodiment of the work machine of the present invention. In FIG. 4, the same reference numerals as those shown in FIGS. 1 to 3 are the same parts, and detailed description thereof is omitted.

The third embodiment of the work machine of the present invention shown in FIG. 4 is configured with devices that are substantially the same as those of the second embodiment, but the following configuration is different.
The present embodiment is different in that a spare device control device 47 is provided. The spare device control device 47 is connected to the host control device 33 via a communication line and is connected to the switching valves 37 to 41 and 43 via a control signal line. The spare device control device 47 includes a signal receiving unit 47a, a control switching unit 47b, and a flow path control unit 47c.

Next, a series of operations for driving the hydraulic actuator in the case where the device control apparatus fails will be described. In addition, about the time of a stop when the apparatus control apparatus is not out of order and the drive method of the boom cylinder 1, since it is the same as that of 2nd Embodiment, it abbreviate | omits.
First, the case where the boom cylinder 1 is extended when the first equipment control device 18 fails and stops will be described.

  When the operation device 34a is operated in the direction in which the boom cylinder 1 is advanced and the operation device 34b is not operated, the flow path selection unit 33a of the host control device 33 operates each operation device 34a, 34b via the control signal line. For example, based on a table set in advance, the first one-side tilt is set to a value corresponding to the operation amount for discharging the pump discharge flow rate command value of the first double tilt pump 35 to the flow path 20 side. The pump discharge flow rate command value of the pump 11 is determined to be a certain positive value corresponding to the operation amount, and the pump discharge flow rate command values of the second both-side tilt pump 36 and the second single tilt pump 12 are determined to be 0. Further, the flow path switching circuit control signal of the switching valve 37 is determined so that the flow path 20 and the flow path 21 are in a flow state, and the flow path switching circuit control signal of the switching valve 41 is set in a flow state with the flow path 42. To decide. Further, all the flow path switching circuit control signals of the switching valves 38 to 40, 43 are determined to be shut off.

  The failure determination unit 33b determines the operation or failure state of the first / second device control apparatuses 18 and 19. For example, when the operation state signal from the first device control device 18 via the communication line is sent to the failure determination unit 33b, the failure state determination method determines that the operation state is normal, and for a certain period of time, If no signal is sent, the first device control device 18 determines that the failure has occurred, and sets the ID of the failed first device control device 18 as the failed device control device ID. Here, the ID is, for example, a unique serial number of the device control apparatus.

  The signal transmission unit 33c transmits the pump discharge flow rate command value to the regulators 35a, 36a, 11a, and 12a via the communication line, and the regulators 35a, 36a, 11a, and 12a receive the pump discharge flow rate command value based on the received pump discharge flow rate command value. The discharge flow rate of the one-bore tilt pump 35 is controlled to be discharged to the flow channel 20 side, the discharge flow rate of the first single tilt pump 11 is set to a certain positive value, and the hydraulic oil is discharged to the flow channel 42 side. Control as follows. Further, the discharge flow rates of the second both-side tilt pump 36 and the second one-side tilt pump 12 are controlled to zero.

  The signal transmission unit 33c transmits the failed device control device ID and the flow path switching circuit control signal to the first / second device control devices 18 and 19 and the spare device control device 47 via the communication line. The signal receiving units 18a, 19a, 47a of the first / second device control devices 18, 19 and the spare device control device 47 receive the failed device control device ID and the flow path switching circuit control signal, respectively.

  The flow path selection unit 47b of the spare device control device 47 selects the drive control target as the switching valves 37, 38, and 41 based on the received failed device control device ID and the flow path switching circuit control signal. At this time, the connection of the control signal line to the drive control target may be either switching by software or switching by an electric circuit using a relay circuit. The flow path control unit 47c controls the switching valves 37 and 42 in the flow state and the switching valve 38 in the shut-off state based on the drive control target selected by the flow path selection unit 47b. On the other hand, the flow path control unit 18b cannot receive a signal because of a failure, and does not output a control signal to the switching valves 37, 38, and 41.

  Since the first double tilt pump 35 and the first single tilt pump 11 discharge the hydraulic oil and the switching valves 37 and 41 are in a flow state, the hydraulic oil discharged by the first double tilt pump 35 flows. The oil flows into the oil chamber on the boom head 1a side via the passage 20, the switching valve 37, and the passage 21. Further, since the first single tilting pump 11 discharges the hydraulic oil to the flow path 42 side and the switching valve 41 is in a circulating state, the hydraulic oil discharged by the first double tilting pump 11 passes through the flow path 42. And then flows into the oil chamber on the boom head 1a side. As a result, the boom cylinder 1 extends. When the boom cylinder 1 extends, hydraulic oil flows from the oil chamber on the boom rod 1 b side into the first double tilt pump 35 through the flow path 23, the switching valve 37, and the flow path 22. At this time, the arm cylinder 3 is stopped.

  By the way, in the second embodiment, when one of the device control devices breaks down, the hydraulic actuator is driven using the device control device operating normally, but the boom cylinder 1 and the arm cylinder 3 Simultaneous drive operation was not considered. Therefore, there is a problem that the operability is lowered as compared with a hydraulic excavator operating normally.

  In this embodiment, since the spare device control device 47 is provided, even if one of the first / second device control devices 18 and 19 fails and stops, the spare device control device instead of the failed device control device. 47 can be used to control the corresponding flow path switching circuit. For this reason, even when the equipment control device fails, the boom cylinder 1 and the arm cylinder 3 can be operated simultaneously. Therefore, even if any device control device fails, it is possible to provide a hydraulic excavator with a high operating rate that can continue the operation while maintaining the operability before the failure of the device control device without stopping the operation.

  According to the third embodiment of the work machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  Further, according to the third embodiment of the work machine of the present invention described above, since the spare device control device 47 is provided, the device control can be performed without stopping the operation even if any device control device fails. It is possible to provide a hydraulic excavator with a high operating rate that can continue the operation while maintaining the operability before the failure of the apparatus.

  Hereinafter, a fourth embodiment of the work machine of the present invention will be described with reference to the drawings. FIG. 5 is a schematic view showing a hydraulic drive device constituting a fourth embodiment of the work machine of the present invention. In FIG. 5, the same reference numerals as those shown in FIGS. 1 to 4 are the same parts, and detailed description thereof is omitted.

The fourth embodiment of the work machine according to the present invention shown in FIG. 5 is configured with the same devices as the second embodiment, but the following configurations are different.
The present embodiment is different in that the display device 48 is provided. The display device 48 is connected to the host control device 33 via a communication line, and includes a signal receiving unit 48a and a display unit 48b.

Next, the operation of driving the hydraulic actuator when the device control apparatus fails in the present embodiment will be described. It should be noted that the stop method when the device control device is not broken and the method of driving the boom cylinder 1 and the drive method of the boom cylinder 1 when the device control device is broken are the same as in the second embodiment, and are omitted. To do.
First, the case where the boom cylinder 1 is extended when the first equipment control device 18 fails and stops will be described.

  The failure determination unit 33b of the host control device 33 determines the operation or failure state of the first / second device control devices 18, 19. For example, when the operation state signal from the first device control device 18 via the communication line is sent to the failure determination unit 33b, the failure state determination method determines that the operation state is normal, and for a certain period of time, If no signal is sent, the first device control device 18 determines that the failure has occurred, and sets the ID of the failed first device control device 18 as the failed device control device ID. Here, the ID is, for example, a unique serial number of the device control apparatus.

  The signal transmission unit 33c of the host control device 33 transmits the failed device control device ID and the flow path switching circuit control signal to the first / second device control devices 18 and 19 and the display device 48 via the communication line. The first / second device control devices 18, 19 and the signal receivers 18a, 19a, 48a of the display device 48 receive the failed device control device ID and the flow path switching circuit control signal, respectively.

  The display unit 48b of the display device 48 displays the received failed device control device ID on the screen. The display unit 48b is a display device such as a display or an LCD, and may be any device that can recognize the malfunction device control device ID.

  By the way, in the second embodiment, when any device control device fails, it is difficult for an operator or a maintenance operator to identify the failed device control device. For this reason, there has been a problem that time-consuming maintenance work such as a specific operation of the failed device control device and a replacement operation of the failed device control device occurs.

  In the present embodiment, since the display device 48 is provided, it becomes easy to identify the failed device control device regardless of which one of the first / second device control devices 18 and 19 fails and stop. Maintenance such as replacement of the device control device can be performed immediately. For this reason, even when the equipment control device fails, the boom cylinder 1 and the arm cylinder 3 can be operated simultaneously. Therefore, even if any device control device fails, the operation of the hydraulic excavator can be quickly returned to normal by performing maintenance immediately and replacing it with a normal device control device. As a result, it is possible to provide a hydraulic excavator with a high operating rate that can suppress a decrease in work amount of the hydraulic excavator.

  According to the fourth embodiment of the work machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  In the above embodiment, the hydraulic circuit for driving the boom cylinder 1 and the arm cylinder 3 is mainly described. However, this technical idea is also applied to the closed circuit and the open circuit of the swing hydraulic motor 7 and the bucket cylinder 5. Is possible. For example, it is effective to apply the present invention to an open / close pump direct control circuit having four closed circuits for driving a boom, an arm, a bucket, and a turn and a flow path switching circuit, and to have four device control devices. .

  The present invention is not limited to the above-described embodiments, and includes various modifications within the scope not departing from the gist thereof. For example, in the above-described embodiment, the case where the present invention is applied to a hydraulic excavator has been described as an example, but the present invention can also be applied to construction machines other than the hydraulic excavator. For example, the present invention can be applied to all work machines including a hydraulic device that drives a plurality of hydraulic actuators by a closed circuit in a work device such as a hydraulic crane.

1: Boom cylinder, 1a: Boom head, 1b: Boom rod, 2: Boom, 3: Arm cylinder, 3a: Arm head, 3b: Arm rod, 4: Arm, 5: Bucket cylinder, 6: Bucket, 7: Swivel Hydraulic motor, 9: engine, 10: power transmission device, 11: first half tilt pump, 12: second half tilt pump, 11a, 12a: regulator, 14-17: switching valve (flow path switching circuit), 18: 1st apparatus control apparatus, 19: 2nd apparatus control apparatus, 18a, 19a: Signal receiving part, 18b, 19b: Flow path control part, 20-31: Flow path, 32: Tank, 33: High-order control apparatus, 33a: flow path selection unit, 33b: failure determination unit, 33c: signal transmission unit, 34a, 34b: operating device, 35: first bilateral tilt pump, 36: second bilateral tilt pump, 35a, 36a: regulator 37 to 41, 43: switching valve (flow path switching circuit), 42, 44: flow path, 45: check valve, 46: flushing valve, 47: spare device control device, 47a: signal receiving section, 47b: control switching section 47c: flow path control unit, 48: display device, 48a: signal receiving unit, 48b: display unit, 100: hydraulic excavator, 101: cab, 102: upper turning body, 104: front work machine

Claims (3)

Multiple hydraulic pumps,
A plurality of hydraulic actuators;
A plurality of hydraulic circuits consists of the flow path for connecting the plurality of hydraulic actuators and the plurality of hydraulic pumps,
A plurality of switching valves for selectively connecting each of the plurality of hydraulic pumps to any one of the plurality of hydraulic actuators ;
In a work machine including an operation device for operating the plurality of hydraulic actuators,
Based on an operation command value of the operating device and a preset relationship among the plurality of hydraulic pumps, the plurality of hydraulic actuators, and the plurality of switching valves, the plurality of switching is performed according to the operation command value of the operating device. A flow path selection unit that selects a switching valve to be in a flow state among the valves, and sets a flow path switching circuit control signal so that the selected switch valve is in a flow state and a non-selected switch valve is in a shut-off state. When,
A host control device having a signal transmission unit that transmits the flow channel switching circuit control signal set by the flow channel selection unit via a communication line;
Provided for each switching valve connected to the same hydraulic pump among the plurality of switching valves, connected to the plurality of switching valves via a control signal line, and connected to the host control device via the communication line. A plurality of device control devices,
The device control device receives the flow path switching circuit control signal from the host control device via the communication line, and drives the plurality of switching valves based on the flow path switching circuit control signal. Including a flow path control unit that generates a command signal to be output and outputs the command signal via the control signal line,
The host control device further includes a failure determination unit that determines whether or not the plurality of device control devices have failed,
The flow path selection unit is connected to the one device control device among the plurality of hydraulic actuators when the failure determination unit determines that one device control device among the plurality of device control devices is failed. In place of the one switching valve, another switching valve connected to another device control device different from the one device control device is provided to the hydraulic actuator that has been supplied with hydraulic oil via the one switching valve. A work machine characterized in that the flow path switching circuit control signal is reset so that hydraulic fluid is supplied via the working fluid . The work machine according to claim 1,
The plurality of hydraulic pumps are a plurality of both tilting hydraulic pumps,
The work machine further includes a plurality of one-side tilt hydraulic pumps,
The plurality of hydraulic circuits include a plurality of closed circuits configured by flow paths connecting each of the plurality of both tilting hydraulic pumps and each of the plurality of hydraulic actuators in a closed circuit shape, and the plurality of both tilting circuits. A work machine comprising a plurality of merging passages that connect each of the rotary hydraulic pumps and the passages constituting the plurality of closed circuits . The work machine according to claim 1,
A display device connected to the host controller via a communication line and having a display unit and a signal receiving unit;
When the failure determination unit determines that the one device control device is a failure, the failure determination unit acquires information on the one device control device ,
The signal transmission unit transmits the information of the one device control device acquired by the failure determination unit to the display device via the communication line,
The work machine characterized in that the signal receiving unit of the display device receives the information of the one device control device, and the display unit displays the received information of the one device control device.

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