JP5961580B2 - Drive device for work machine - Google Patents

Description

  The present invention relates to a drive device for a work machine including a hydraulic closed circuit that directly drives a hydraulic actuator by a hydraulic pump.

  In recent years, energy-saving systems have attracted attention in work machines such as hydraulic excavators and wheel loaders, and hybrid work machines that recover regenerative energy during braking have been put on the market. However, in many of the hybrid work machines on the market at present, the drive unit is an electric system added to a conventional hydraulic system, and the flow rate to the hydraulic actuator is controlled by a control valve that is a directional control valve. There is no change in adjusting the degree, that is, adjusting the pressure while reducing the pressure loss.

  In order to save energy in the work machine, it is important to save energy in the hydraulic system itself. In particular, a great effect can be obtained in reducing the throttle pressure loss generated in the control valve. Therefore, as a drive device for a work machine that saves energy, a hydraulic closed circuit system in which a hydraulic pump and a hydraulic actuator are connected in a closed circuit and directly controlled by the hydraulic pump is being developed. Since this system does not use a control valve, there is no throttle pressure loss due to the control valve, and the hydraulic pump discharges only the necessary flow rate, so that the flow rate loss can be reduced. In addition, the position energy of the hydraulic actuator and the energy during deceleration can be regenerated, which is a very effective system as an energy saving system.

  As a prior art of the hydraulic closed circuit system, there is a technique disclosed in Patent Document 1. This Patent Document 1 discloses a hydraulic circuit of a work machine such as a hydraulic excavator as an example of a hydraulic closed circuit system. This hydraulic closed circuit system can secure the flow rate desired by the operator even during complex operation by connecting a hydraulic pump that is not operating to the hydraulic actuator according to a preset connection pattern between the hydraulic pump and the hydraulic actuator. .

JP-A-57-54635

  In the technique disclosed in Patent Document 1 described above, the case where the hydraulic pump has failed for some reason is not considered, and as a result, the hydraulic actuator that has been supplied with pressure oil from the failed hydraulic pump is difficult to operate. Or, there is a possibility that problems such as getting stuck may occur. In this case, the work is interrupted and the work process is hindered. For work machines used at mines, etc., a machine equipped with such a hydraulic closed circuit system is desired from the viewpoint of fuel efficiency. A response that is limited to the limit is desired.

  The present invention has been made based on the above-described actual situation in the prior art, and an object of the present invention is to drive a work machine that allows continuation of work even when one or more hydraulic pumps used in a hydraulic closed circuit system fail. To provide an apparatus.

In order to achieve this object, the present invention provides a prime mover, a plurality of hydraulic actuators, a plurality of hydraulic pumps supplied with driving force by the prime mover and having a larger number than the plurality of hydraulic actuators, and a discharge of the hydraulic pump a discharge flow rate changing device for the flow rate variable, the front SL hydraulic actuator and connection device for connecting a closed circuit and at least one or more of said hydraulic pump, and an operating device for generating an operation signal to the hydraulic actuator, In accordance with an operation signal of the operating device, a connection setting unit that sets a priority order of connection of the plurality of hydraulic pumps to the plurality of hydraulic actuators, and according to a connection setting signal from the connection setting unit A control device for controlling the discharge flow rate variable device and the connection device, and a hydraulic pump state quantity detection for detecting a state quantity of the hydraulic pump And a hydraulic pump failure determination unit that determines a failure of the hydraulic pump based on a detection signal from the hydraulic pump state quantity detection device, wherein the connection setting unit includes the hydraulic pressure When the pump failure determination unit determines that at least one of the plurality of hydraulic pumps has failed , the connection setting between the hydraulic pump and the hydraulic actuator is excluded from the failed hydraulic pump and connected to the failed hydraulic pump. A process of changing the order of priority connection of the plurality of hydraulic pumps to the plurality of hydraulic actuators is performed so that a hydraulic pump different from the failed hydraulic pump is connected to the actuator that has been It is said.

  According to the present invention configured as described above, a certain hydraulic pump is provided by the calculation of the connection setting unit that is provided in the control device and performs the change processing of the connection setting between the hydraulic pump and the hydraulic actuator in consideration of the failure state of the hydraulic pump. Even if a failure occurs, it is possible to continue the work.

  The present invention is the above invention, wherein the control device has at least one connection pattern between the hydraulic pump and the hydraulic actuator, and selects the connection pattern according to an output signal from the hydraulic pump failure determination unit. A connection pattern selection unit is provided, and the connection setting unit performs a process of changing connection settings between the hydraulic pump and the hydraulic actuator based on the connection pattern selected by the connection pattern selection unit. .

  The present invention configured as described above has one or more connection patterns between the hydraulic pump and the hydraulic actuator, and the operation of the connection setting unit that performs connection setting change processing based on the connection pattern corresponds to the failed hydraulic pump. Connection settings can be made.

  The present invention relates to a hydraulic pump used in a hydraulic closed circuit system by calculation of a connection setting unit that performs connection setting change processing between a hydraulic pump and a hydraulic actuator in consideration of a hydraulic pump failure situation that has not been considered in the past. Even if one or more of the devices break down, the work can be continued without causing any trouble in the work process due to the interruption of the work, which has been a concern. As a result, the present invention can improve the workability in the field as compared with the prior art.

1 is a side view showing a hydraulic excavator including a first embodiment of a drive device for a work machine according to the present invention. It is a circuit block diagram which shows 1st Embodiment of the drive device with which the hydraulic shovel shown in FIG. 1 is equipped. It is a figure which shows the connection relation of the hydraulic pump state quantity detection apparatus with which 1st Embodiment shown in FIG. 2 is equipped, and a controller. It is a figure which shows the principal part of the controller with which 1st Embodiment shown in FIG. 2 is equipped. It is a flowchart figure which shows the control process of the controller shown in FIG. FIG. 5 is a characteristic diagram illustrating a relationship between a lever operation amount and a hydraulic actuator required flow rate, which the hydraulic actuator required flow rate calculation unit illustrated in FIG. 4 has. It is a flowchart figure which shows the control process performed by the process of step S4 shown in FIG. 5, ie, a connection pattern selection part, and a connection judgment part. FIG. 5 is a relationship diagram illustrating an example of a connection pattern between a hydraulic actuator of a connection determination unit illustrated in FIG. 4 and a connectable hydraulic pump. It is a time series figure which shows the input timing of the lever operation amount of the operating device with which a 1st embodiment shown in Drawing 2 is provided, and is a figure showing the example of operation of a 1st embodiment. It is a figure which shows the example of an effect | action of 1st Embodiment demonstrated with the characteristic diagram shown in FIG. It is a figure which shows the example of an effect | action at the time of the hydraulic pump normality in 1st Embodiment demonstrated with the relationship diagram shown in FIG. FIG. 3 is a time-series diagram illustrating a discharge timing of a target discharge flow rate of the hydraulic pump provided in the first embodiment shown in FIG. 2, and a diagram illustrating an operation example when the hydraulic pump is normal in the first embodiment. It is a figure which shows the example of an effect | action at the time of the hydraulic pump failure in 1st Embodiment demonstrated with the relationship diagram shown in FIG. FIG. 5 is a time-series diagram illustrating the discharge timing of the actual discharge flow rate of the hydraulic pump provided in the first embodiment shown in FIG. 2, and is a diagram illustrating an operation example when the hydraulic pump fails in the first embodiment. It is a figure which shows the example of an effect | action at the time of the connection pattern setting according to the hydraulic pump which failed in 1st Embodiment demonstrated with the relationship diagram shown in FIG. FIG. 3 is a time-series diagram illustrating a discharge timing of a target discharge flow rate of the hydraulic pump provided in the first embodiment shown in FIG. 2, and a diagram illustrating an operation example when setting a connection pattern according to a failed hydraulic pump in the first embodiment. is there. It is a circuit block diagram which shows 2nd Embodiment of the drive device of the working machine which concerns on this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a working machine drive device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a hydraulic excavator including a first embodiment of a drive device for a work machine according to the present invention.

  The hydraulic excavator including the first embodiment includes a traveling body 101, and a revolving body 102 is provided on the traveling body 101. The traveling body 101 and the swivel body 102 constitute a main body. The traveling body 101 is a hydraulic actuator, and is provided with a traveling motor 10b that applies traveling power to the left and right crawler belts and a traveling motor 10a (not shown). The turning body 102 can turn with respect to the traveling body 101 by a turning motor 10c which is a hydraulic actuator described later. In addition, the swivel body 102 includes a main frame 105, a work device 103 at the front, a counterweight 108 at the rear, and a cab 104 at the left front. An engine 106 as a prime mover is provided on the front side of the counterweight 108, and further includes a drive device 107 that is driven by a drive output from the engine 106.

  In the work device 103, a structure including a boom 111, an arm 112, and a bucket 113 is coupled by a link mechanism, and each of the work devices 103 performs a rotational motion around the link shaft to perform work such as excavation. In order to rotate each of the boom 111, the arm 112, and the bucket 113, a boom cylinder 7a, an arm cylinder 7b, and a bucket cylinder 7c, which are hydraulic actuators, are provided.

  2 is a circuit configuration diagram showing the first embodiment of the drive device 107 provided in the hydraulic excavator shown in FIG. 1, and FIG. 3 is a hydraulic pump state quantity detection device provided in the first embodiment shown in FIG. FIG. 4 is a diagram showing a connection relationship between the pressure sensors 30a to 30l and the controller 41, and FIG. 4 is a diagram showing a main part of the controller 41 provided in the first embodiment shown in FIG.

As shown in FIG. 2, the drive device 107 according to the first embodiment is controlled by variable displacement hydraulic pumps 2a to 2f that are hydraulic pumps, a boom cylinder 7a, an arm cylinder 7b, a bucket cylinder 7c, and a swing motor 10c. A hydraulic closed circuit system connected via piping without using a valve, variable displacement hydraulic pumps 1a and 1b, and travel motors 10a and 10b via a control valve 11 for controlling the supply flow rate and direction, It consists of a hydraulic open circuit system connected using piping.

  In the first embodiment, the hydraulic closed circuit system and the hydraulic open circuit system are mixed, but this is not particular, and depending on the application of the work machine, for example, all hydraulic actuators may be configured with a hydraulic closed circuit system. It may take the form of

  Here, the hydraulic closed circuit system described above will be described.

There are provided an engine 106 and a plurality of variable displacement hydraulic pumps 2a to 2f that are supplied with a drive output consisting of torque and rotational speed by the engine 106 via a power transmission device 13 constituted by a gear mechanism or the like. Hydraulic regulators 3a to 3f that are variable discharge flow rates of the variable displacement hydraulic pumps 2a to 2f, a boom cylinder 7a, an arm cylinder 7b, a bucket cylinder 7c, a swing motor 10c, and a boom cylinder 7a, An electromagnetic switching valve 12, which is a connecting device for hydraulically connecting the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c to at least one of the variable displacement hydraulic pumps 2a to 2f, the boom cylinder 7a, the arm Operation to cylinder 7b, bucket cylinder 7c, and swing motor 10c An operating device 40a, 40b for generating a lever operation amount is No. The operating device 40a, in response to the lever operation amount of 40b, a variable displacement hydraulic pump 2a ~ 2f and the boom cylinder 7a, an arm cylinder 7b, a bucket cylinder 7c, And a control device that controls the hydraulic regulators 3a to 3f and the electromagnetic switching valve 12 according to a connection setting signal from the connection setting unit 41b, and a variable displacement type. Based on pressure sensors 30a to 30l that are hydraulic pump state quantity detection devices that detect discharge pressures that are state quantities of the hydraulic pumps 2a to 2f, and variable displacement hydraulic pumps 2a to 2 based on detection signals from the pressure sensors 30a to 30l. A hydraulic pump failure determination unit 41d that determines the failure of 2f.

  That is, the variable displacement hydraulic pumps 2a to 2f are provided in the variable displacement hydraulic pumps 2a to 2f in order to provide the drive direction and discharge flow rate of the boom cylinder 7a, the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c. A bidirectional discharge mechanism is provided that can discharge pressure oil from each of the two connection ports, and the bidirectional discharge mechanism is controlled by hydraulic regulators 3a to 3f.

When pressure oil is discharged from one of the two connection ports of the variable displacement hydraulic pumps 2a to 2f by the bidirectional discharge mechanism, the boom cylinder 7a, the arm cylinder 7b, The bucket cylinder 7c and one of the two connection ports provided in any of the hydraulic actuators in the swing motor 10c are connected to one of the connection ports, and the two of the connection ports provided in any of the hydraulic actuators. The return pressure oil is returned from the other connection port to the other connection port among the two connection ports of the variable displacement hydraulic pumps 2 a to 2 f via the electromagnetic switching valve 12. That is, a hydraulic closed circuit is configured in which the pressure oil does not return to the tank 9 and circulates between the variable displacement hydraulic pumps 2a to 2f and the hydraulic actuator.

In the hydraulic closed circuit system, the positional energy of the boom 111 and the arm 112 generated when the boom 111 and the arm 112 are lowered in the direction of gravity or when the turning operation of the turning body 102 is stopped, and the kinetic energy of the turning body 102. Becomes regenerative energy, is transmitted to the return pressure oil, and is transmitted to one of the variable displacement hydraulic pumps 2a to 2f. At this time, the variable displacement hydraulic pumps 2a to 2f are regenerated by the regenerative energy. This regenerative energy is transmitted as drive output to any one of the variable displacement hydraulic pumps 2a to 2f driving other hydraulic actuators via the power transmission device 13. As a result, an energy saving effect corresponding to the regenerative energy is obtained for the engine 106.

  The electromagnetic switching valve 12 is “BM” for connecting a plurality of the variable displacement hydraulic pumps 2a to 2f to one of the boom cylinder 7a, the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c. The switch valve includes a total of 18 electromagnetic switch valves including a switch valve for “AM”, a switch valve for “BK”, and a switch valve for “SW”.

Among the electromagnetic switching valves 12, the “BM” switching valve is a switching valve for connecting to the boom cylinder 7a, and is connected to all of the variable displacement hydraulic pumps 2a to 2f located upstream of the electromagnetic switching valve 12. It is provided as possible. The “AM” switching valve is a switching valve for connecting to the arm cylinder 7b. Among the variable displacement hydraulic pumps 2a to 2f located upstream of the electromagnetic switching valve 12, the variable displacement hydraulic pumps 2a to 2d are the maximum. Are provided so that they can be connected. The “BK” switching valve is a switching valve for connection to the bucket cylinder 7c, and is provided so that all of the variable displacement hydraulic pumps 2a to 2f located upstream of the electromagnetic switching valve 12 can be connected. ing. The “SW” switching valve is a switching valve for connection to the swing motor 10c. Among the variable displacement hydraulic pumps 2a to 2f located upstream of the electromagnetic switching valve 12, the variable displacement hydraulic pumps 2e and 2f are the maximum. Are provided so that they can be connected.

  In addition, the connection form of the above-mentioned electromagnetic switching valve 12 is not particular to this, and another connection form may be used depending on the use of the work machine.

  A driver's cab 104 in which an operator is boarded is provided with operating devices 40a and 40b for giving an operation command to the hydraulic actuator. Although not shown, the operation devices 40a and 40b include a lever that can be tilted forward and backward, left and right, and a detection device (not shown) that electrically detects a tilt amount of the lever as an operation signal, that is, a lever operation amount. The lever operation amount is output to the controller 41, which is a control device, via electric wiring. In addition, although the above-described operating devices 40a and 40b have a mechanism for electrically detecting the lever operation amount, they are not particularly limited to this and may be another mechanism such as a hydraulic mechanism.

As shown in FIG. 3, the above-described pressure sensors 30a to 30l, which are the hydraulic pump state quantity detection devices, detect the discharge pressure of the pressure oil discharged from the two connection ports of the variable displacement hydraulic pumps 2a to 2f. It is installed in. The discharge pressure detected by the pressure sensors 30a to 30l is output to the hydraulic pump failure determination unit 41d of the controller 41. The reason why the pressure sensors 30a to 30l are used is that the discharge pressure may not increase as a phenomenon when the hydraulic pump fails, and the failure can be determined based on the detected discharge pressure. One reason why the discharge pressure does not increase is a decrease in volumetric efficiency due to wear inside the hydraulic pump. In the present embodiment, an example using the pressure sensors 30a to 30l is shown, but the phenomenon at the time of the hydraulic pump failure is not limited to the discharge pressure, but includes a decrease in discharge flow rate, abnormal noise, etc. A corresponding hydraulic pump state quantity detection device such as a flow meter may be used.

  The controller 41 performs a control calculation described later, outputs a target discharge flow rate described later to the hydraulic regulators 3a to 3f, and outputs a switching valve connection command signal to the electromagnetic switching valve 12, respectively. Take control.

  In addition, although it is a hydraulic open circuit system, as mentioned above, since the control valve 11 for giving the drive direction and discharge flow rate of traveling motor 10a, 10b is provided downstream, the variable which comprises a hydraulic open circuit system is comprised. The displacement type hydraulic pumps 1a and 1b include a one-way discharge mechanism. That is, the variable displacement hydraulic pumps 1a, 1b are suction ports that suck one of the two connection ports provided in the variable displacement hydraulic pumps 1a, 1b from the tank 9 for temporarily storing pressure oil. As described above, the pipe 9 is connected to the tank 9 and the other connection port is connected to the connection port of the control valve 11 as a discharge port. The discharge flow rate from the discharge port is controlled by a one-way discharge mechanism. The one-way discharge mechanism is controlled by hydraulic regulators 3g and 3h. Further, the return flow rate from the traveling motors 10 a and 10 b is returned to the tank 9 via the control valve 11. The control valve 11 and the hydraulic regulators 3g and 3h are controlled according to a lever operation amount generated by an operating device (not shown) provided in the cab 104. The lever operation amount is output to the controller 41. The controller 41 performs a control operation different from a hydraulic closed circuit system (not shown), converts it into an output signal, and connects the control valve 11 and the hydraulic regulator via the electrical wiring. Output to 3g, 3h.

  Hereinafter, the description returns to the hydraulic closed circuit system.

  Next, the configuration of the controller 41 will be described with reference to FIG.

  That is, the connection setting unit 41b included in the controller 41 includes the variable displacement hydraulic pumps 2a to 2f, the boom cylinder 7a, the arm cylinder 7b, the bucket cylinder 7c, and the like according to the output signal from the hydraulic pump failure determination unit 41d. Processing for changing the connection setting with the swing motor 10c is performed.

  The controller 41 has one or more connection patterns of the variable displacement hydraulic pumps 2a to 2f and the boom cylinder 7a, the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c. A connection pattern selection unit 41e for setting a connection pattern according to the output signal is provided, and the connection setting unit 41b is connected to the variable displacement hydraulic pumps 2a to 2f and the boom based on the connection pattern selected by the connection pattern selection unit 41e. Processing for changing connection settings of the cylinder 7a, the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c is performed.

  Further, the controller 41 calculates the required flow rate to the boom cylinder 7a, arm cylinder 7b, bucket cylinder 7c, and swing motor 10c in accordance with the lever operation amount from the operation devices 40a, 40b, and outputs it to the connection setting unit 41b. The target discharge flow rate setting unit 41a sets the target discharge flow rate of the variable displacement hydraulic pumps 2a to 2f based on the calculation results from the hydraulic actuator required flow rate calculation unit 41a and the connection setting unit 41b, and outputs them to the hydraulic regulators 3a to 3f. From the information on the hydraulic actuators to be operated obtained from the unit 41c, the target discharge flow rate setting unit 41c, and the hydraulic pumps to be connected to them, a connection command to the electromagnetic switching valve to be opened among the electromagnetic switching valves 12 The switching valve connection command calculating unit 41f is provided.

  The lines connecting the parts are signal lines indicating the input / output relationship of data such as the lever operation amount, the discharge pressure, and the calculation result, and the data can be shared between the parts in the controller 41. It has become.

  Next, the control process of the controller 41 shown in FIG. 4 will be described.

  FIG. 5 is a flowchart showing the control process of the controller 41 shown in FIG. 4, and FIG. 6 is a characteristic showing the relationship between the lever operation amount and the hydraulic actuator required flow rate, which the hydraulic actuator required flow rate calculation unit 41a shown in FIG. FIG. 7 is a flowchart showing the process of step S4 shown in FIG. 5, that is, a control process performed by the connection pattern selection unit 41e and the connection determination unit 41b. FIG. 8 is a connection determination unit 41b shown in FIG. It is a related figure which shows an example of the connection pattern with the hydraulic pump which can be connected with this hydraulic actuator.

  The control process of the controller 41 shown in FIG. 5 starts the control at the start of step S1 shown in FIG. 5, and returns to the start of step S1 when reaching the return of step S6. This control is performed at a preset cycle by an internal timer (not shown) provided in the controller 41.

  When control starts in step S1, the process proceeds to step S2. The control in step S1 is activated when the controller 41 inputs an instruction signal from an external device (not shown) such as a key operation for instructing the engine 106 to start or a dedicated switch.

  In step S2, the lever operation amount generated when the operator operates the operating device 40a or 40b indicates a stroke input to the hydraulic actuator required flow rate calculation unit 41a, and the process proceeds to step S3.

  Step S3 shows a process of calculating the required flow rate to the hydraulic actuator that is the operation target in accordance with the lever operation amount in the hydraulic actuator required flow rate calculation unit 41a. In this embodiment, the calculation using the characteristic diagram showing the relationship between the lever operation amount and the hydraulic actuator required flow rate shown in FIG. 6 is exemplified. In this characteristic diagram, the required flow rate has a one-to-one proportional relationship with the lever operation amount, and the required flow rate can be uniquely calculated for a certain lever operation amount. Information for specifying the hydraulic actuator to be operated and the required flow rate are output to the outside, and the process proceeds to step S4. Since each hydraulic actuator can operate in two directions, eight characteristic diagrams are required for the boom, arm, bucket, and swivel. The characteristics of the required flow rate of each hydraulic actuator are the same and are shown by four characteristic diagrams.

  In step S4, the connection determining unit 41b connects the hydraulic actuator that is the operation target from the hydraulic actuator required flow rate calculating unit 41a and the connection pattern from the connection pattern selecting unit 41e based on the failure determination in the hydraulic pump failure determining unit 41d. A process of determining a hydraulic pump that can be connected to the hydraulic actuator to be operated among the variable displacement hydraulic pumps 2a to 2f in accordance with the selection result and further setting a connection priority, that is, a connection order is shown. In this embodiment, the flowchart shown in FIG. 7 is illustrated as a control process of step S4.

  In step S401, a failure determination is made by the hydraulic pump failure determination unit 41d according to the discharge pressure detected by the pressure sensors 30a to 30l. The failure determination can be performed, for example, by comparing the detected discharge pressure with a preset threshold value. If the hydraulic pump is normal, the process proceeds to step S402. On the other hand, if the hydraulic pump is not normal, that is, has failed, the process proceeds to step S403. The hydraulic pump failure determination unit 41d outputs the presence / absence of a failed hydraulic pump and the identification number of the failed hydraulic pump, for example, 2a to 2f, to the outside.

  In step S402, when the hydraulic pump failure determination unit 41d determines that the hydraulic pump is out of order, that is, is normal, the connection pattern selection unit 41e includes the reference connection pattern. Is selected and output to the outside. Note that the control process proceeds to step S404.

  In the present embodiment, as an example of the reference connection pattern, a connection pattern of a hydraulic pump that can be connected to the hydraulic actuator illustrated in FIG. 8 is illustrated. This connection pattern indicates the hydraulic pumps connected to the hydraulic actuators to be operated and the connection order. That is, in the numbers shown in the connection pattern shown in FIG. 8, a single number or a number on the left side of “/” is preferentially connected to the hydraulic actuator that is the operation target of the variable displacement hydraulic pumps 2a to 2f. The number on the right side of “/” indicates the priority when the connection order of the variable displacement hydraulic pumps 2a to 2f indicated by the number on the left side of “/” is the same in the same hydraulic actuator. Indicates the connection order for determining whether connection is possible.

  For example, when the hydraulic actuator to be operated is the boom cylinder 7a, the connectable hydraulic pumps are all the variable displacement hydraulic pumps 2a to 2f, and the connection order is 2a, 2d, 2b, 2e, 2f, 2c. In order. When the hydraulic actuators to be operated are the boom cylinder 7a and the swing motor 10c, the hydraulic pumps that can be connected to the boom cylinder 7a and their connection order are variable displacement hydraulic pumps 2a, 2d, 2b, 2c, The hydraulic pumps that can be connected to the swing motor 10c and their connection order are 2e and 2f. It is assumed that the required flow rate of the boom cylinder 7a is required for five hydraulic pumps and the required flow rate of the swing motor 10c may be as much as one variable displacement hydraulic pump 2e. For the sake of simple explanation, the connection specifications as described above are used.

  In step S403, when the hydraulic pump failure determination unit 41d determines that the hydraulic pump has failed, the connection pattern selection unit 41e selects a failure connection pattern from among the connection patterns and outputs it to the outside. Note that the control process proceeds to step S404.

  In step S404, the connection setting unit 41b selects the connection pattern from the connection pattern selection unit 41e based on the hydraulic actuator that is the operation target from the hydraulic actuator required flow rate calculation unit 41a and the failure determination in the hydraulic pump failure determination unit 41d. In accordance with the result, among the variable displacement hydraulic pumps 2a to 2f, the connection order of the hydraulic pumps that can be connected to the hydraulic actuator to be operated is set and output to the outside. In addition, a control process transfers to step S5.

  Step S5 shown in FIG. 5 is a target discharge flow rate setting unit 41c based on the outputs of the hydraulic actuator required flow rate calculation unit 41a and the connection setting unit 41b, and the target discharge flow rate of the hydraulic pump for the hydraulic actuator that is the operation target. Is set and output to the outside. The control process proceeds to step S6.

  Next, the operation of the first embodiment will be described.

  FIG. 9 is a time series diagram showing the input timing of the lever operation amount of the operating devices 40a and 40b provided in the first embodiment shown in FIG. 2, and is a diagram showing an example of the operation of the first embodiment, and FIG. FIG. 11 is a diagram illustrating an operation example of the first embodiment, which is described with reference to a characteristic diagram shown in FIG. FIG. 12 is a time-series diagram showing the discharge timing of the target discharge flow rate of the hydraulic pump provided in the first embodiment shown in FIG. 2, and is a diagram showing an operation example when the hydraulic pump is normal in the first embodiment. FIG. 14 is a diagram illustrating an example of an action when the hydraulic pump fails in the first embodiment, which is described with reference to the relational diagram illustrated in FIG. 8. FIG. In the time series diagram showing the discharge timing, in the first embodiment FIG. 15 is a diagram illustrating an example of operation when a hydraulic pump fails, FIG. 15 is a diagram illustrating an example of operation when setting a connection pattern according to the malfunctioning hydraulic pump according to the first embodiment, and FIG. 16 is a time-series diagram showing the discharge timing of the target discharge flow rate of the hydraulic pump provided in the first embodiment shown in FIG. 2, and an example of operation when setting the connection pattern according to the failed hydraulic pump in the first embodiment. FIG.

  As an example of operation when the hydraulic pump is normal in the first embodiment, an example of operation during the combined operation of the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c will be described with reference to FIGS.

  As shown in FIG. 9, the operation devices 40 a and 40 b are operated in time series in the order of bucket, swivel, and arm, and the lever operation amount corresponding to these is input to the hydraulic actuator required flow rate calculation unit 41 a of the controller 41. . This control process is step S2 described above.

  The hydraulic actuator required flow rate calculation unit 41a calculates the required flow rate to the hydraulic actuator that is the operation target according to the lever operation amount as shown in FIG. That is, for each lever operation amount, the arm cylinder 7b obtains the necessary flow rate QA1, the bucket cylinder 7c obtains the necessary flow rate QA2, and the swing motor 10c obtains the necessary flow rate QA3 and outputs them to the outside. In order to simplify the description here, the required flow rate QA1 is equal to the sum of the maximum discharge flow rates of the variable displacement hydraulic pumps 2a and 2b, and the required flow rate QA2 is the maximum discharge flow rate of the variable displacement hydraulic pumps 2c and 2f. Further, it is assumed that the required flow rate QA3 is equal to the maximum discharge flow rate of the variable displacement hydraulic pump 2e. This control process is the above-described step S3.

  The process proceeds from step 3 to step 4 described above. The hydraulic pump failure determination unit 41d determines that the hydraulic pump is normal based on the discharge pressure detected by the pressure sensors 30a to 30l, and outputs a determination result indicating that there is no faulty hydraulic pump, that is, normal. . This control process is the above-described step S401.

  The connection pattern selection unit 41e selects a reference connection pattern from the determination result that there is no faulty hydraulic pump, that is, normal input, which is input from the hydraulic pump failure determination unit 41d, and outputs it to the outside. This control process is the aforementioned step S402.

  In the connection setting unit 41b, among the variable displacement hydraulic pumps 2a to 2f, depending on the hydraulic actuator that is the operation target from the hydraulic actuator required flow rate calculation unit 41a and the reference connection pattern selected by the connection pattern selection unit 41e, The connection order of the hydraulic pumps that can be connected to the hydraulic actuator to be operated is set to the hydraulic pumps covered with () in FIG. That is, the arm cylinder 7b is a variable displacement hydraulic pump 2b, 2a, the bucket cylinder 7c is a variable displacement hydraulic pump 2c, 2f, 2d, and the swing motor 10c is a variable displacement hydraulic pump 2e. After setting these, output to the outside. This control process is step S404 described above.

  In the target discharge flow rate setting unit 41c, a required flow rate QA1 for the arm cylinder 7b from the hydraulic actuator required flow rate calculation unit 41a, a required flow rate QA2 for the bucket cylinder 7c, a required flow rate QA3 for the swing motor 10c, and a diagram from the connection setting unit 41b. 11, the target discharge flow rate of the hydraulic pump for the hydraulic actuator that is the operation target is set as shown in FIG. 12 and output to the outside.

  FIG. 12 shows the target discharge flow rate setting of the hydraulic pump in time series according to the input timing of the lever operation amount. The bucket cylinder 7c outputs a target discharge flow rate to each of the variable displacement hydraulic pumps 2c and 2f because the required flow rate QA2, and the swing motor 10c outputs a target discharge flow rate to the variable displacement hydraulic pump 2e because of the required flow rate QA3. Furthermore, the arm cylinder 7b outputs the target discharge flow rate to the variable displacement hydraulic pumps 2b and 2a because the required flow rate QA1. This control process is step S5 described above.

  Next, as an example of action when the hydraulic pump fails in the first embodiment, an example of action during combined operation of the arm cylinder 7b, the bucket cylinder 7c, and the swing motor 10c will be described with reference to FIGS. Note that the lever operation amount, the maximum discharge flow rate of the hydraulic pump, etc. are the same values as when the hydraulic pump is normal.

  Here, it is assumed that the reference connection pattern is used as it is without judging the failure of the hydraulic pump. For example, when the variable displacement hydraulic pump 2e fails, a boom cylinder 7a, a bucket cylinder 7c, and a swing motor 10c that can be connected to the variable displacement hydraulic pump 2e in the reference connection pattern as shown by “x” in FIG. The discharge flow rate cannot be supplied. Therefore, in this case, as shown in FIG. 14, the flow rate actually discharged to the swing motor 10c, that is, the actual discharge flow rate cannot be supplied, which hinders work.

  Therefore, in this embodiment, in step S401 described above, the hydraulic pump failure determination unit 41d determines that the variable displacement hydraulic pump 2e has failed, and outputs it to the connection pattern selection unit 41e. The connection pattern selection unit 41e inputs that the variable displacement hydraulic pump 2e has failed. In step S403 described above, the failure connection pattern shown in FIG. 15 is selected and output to the outside.

  In the connection setting unit 41b, among the variable displacement hydraulic pumps 2a to 2f, depending on the hydraulic actuator that is the operation target from the hydraulic actuator required flow rate calculation unit 41a and the failure connection pattern selected by the connection pattern selection unit 41e, The connection order of the hydraulic pumps that can be connected to the hydraulic actuator to be operated is set to the hydraulic pumps covered with () in FIG. That is, the arm cylinder 7b is a variable displacement hydraulic pump 2b, 2a, the bucket cylinder 7c is a variable displacement hydraulic pump 2c, 2d, and the swing motor 10c is a variable displacement hydraulic pump 2f. After setting these, output to the outside. This control process is step S404 described above.

  In the target discharge flow rate setting unit 41c, a required flow rate QA1 for the arm cylinder 7b from the hydraulic actuator required flow rate calculation unit 41a, a required flow rate QA2 for the bucket cylinder 7c, a required flow rate QA3 for the swing motor 10c, and a diagram from the connection setting unit 41b. From the connection order shown in FIG. 15, the target discharge flow rate of the hydraulic pump for the hydraulic actuator that is the operation target is set as shown in FIG. As a result, the swivel motor 10c can be supplied from the variable displacement hydraulic pump 2f, and the work is not hindered. This control process is step S5 described above.

  According to this embodiment configured as described above, hydraulic connection is closed by calculation of a connection setting unit that performs processing for changing the connection setting between the hydraulic pump and the hydraulic actuator in consideration of a hydraulic pump failure situation that has not been considered in the past. Even when one or more hydraulic pumps used in the circuit system fail, the work can be continued without causing any trouble in the work process due to the interruption of the work which has been a concern. As a result, this embodiment can improve the workability in the field compared with the past.

  FIG. 17 is a circuit configuration diagram showing a second embodiment of the working machine drive device according to the present invention.

  The description of the elements having the same reference numerals as in the first embodiment is omitted.

  As shown in FIG. 17, the drive device 207 according to the second embodiment includes an electric motor 116 that is a prime mover, instead of the engine 106 in the first embodiment. That is, the electric motor 116 inputs power from the external power supply 118 via the control panel 117. The external power source 118 may be a general commercial power source. The control panel 117 includes a breaker (not shown), a starting device, and the like, and is provided in the revolving body 102. The drive output of the electric motor 116 is transmitted to the variable displacement hydraulic pumps 2 a to 2 f via the power transmission device 13. Other configurations are the same as those in the first embodiment.

  A work machine equipped with the electric motor 116 shown in the present embodiment as a prime mover is often used in, for example, mining excavators, metal scrap processing machines, and the like.

  The second embodiment configured as described above can obtain the same effects as those of the first embodiment.

  In the first embodiment, the hydraulic pump failure determination unit 41d is included in the controller 41. However, the configuration is not limited to this and may be provided separately from the controller 41. Further, the connection patterns may be different connection patterns depending on the work situation or the like, regardless of those shown in FIG. 8 or FIG. 15, and a plurality of connection patterns may be prepared in consideration of this. Furthermore, in the first embodiment, one failed hydraulic pump is shown, but if another connection pattern is prepared in advance, change processing is possible even when a plurality of failures occur.

2a-2f Variable displacement hydraulic pump (hydraulic pump)
3a-3f Hydraulic regulator (Discharge flow rate variable device)
7a Boom cylinder (hydraulic actuator)
7b Arm cylinder (hydraulic actuator)
7c Bucket cylinder (hydraulic actuator)
10c slewing motor (hydraulic actuator)
12 Electromagnetic switching valve (connection device)
13 Power transmission device 30a-30l Pressure sensor (hydraulic pump state quantity detection device)
40a, 40b Operating device 41 Controller (control device)
41a Hydraulic actuator required flow rate calculation unit 41b Connection setting unit 41c Target discharge flow rate setting unit 41d Hydraulic pump failure determination unit 41e Connection pattern selection unit 41f Switching valve connection command calculation unit 101 Traveling body 102 Revolving body 103 Working device 104 Operating room 106 Engine ( Prime mover)
107 Drive device 111 Boom 112 Arm 113 Bucket 116 Electric motor (prime mover)
207 Drive device

Claims (2)

A prime mover, a plurality of hydraulic actuators, a plurality of hydraulic pumps supplied with driving force by the prime mover and having a larger number than the plurality of hydraulic actuators, and a discharge flow rate variable device for varying the discharge flow rate of the hydraulic pumps ; before Symbol hydraulic actuator and at least one of said hydraulic pump and connecting device for connecting a closed circuit and a operating device for generating an operation signal to the hydraulic actuator in response to an operation signal of the operating device, wherein a plurality of hydraulic pumps include a connection setting section for setting a rank that preferentially connected to said plurality of hydraulic actuators, according to the connection setting signal from the connection setting unit, and the discharge flow rate changing device and the connecting device A control device for controlling the hydraulic pump, a hydraulic pump state quantity detection device for detecting a state quantity of the hydraulic pump, and the hydraulic pump state quantity detection device Based on the detection signals from, in that in the drive system including a hydraulic pump failure judgment unit for judging a failure of the hydraulic pump,
When the hydraulic pump failure determination unit determines that at least one of the plurality of hydraulic pumps has failed , the connection setting unit excludes the failed hydraulic pump from setting the connection between the hydraulic pump and the hydraulic actuator. The order of priority connection of the plurality of hydraulic pumps to the plurality of hydraulic actuators is such that a hydraulic pump different from the failed hydraulic pump is connected to the actuator connected to the failed hydraulic pump. A drive device for a work machine, characterized by performing a process of changing. In the work machine drive device according to claim 1,
The control device includes one or more connection patterns between the hydraulic pump and the hydraulic actuator, and includes a connection pattern selection unit that selects the connection pattern according to an output signal from the hydraulic pump failure determination unit,
The connection setting unit performs a process of changing the connection setting between the hydraulic pump and the hydraulic actuator based on the connection pattern selected by the connection pattern selection unit.