JP2012021394A - Working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine which enables easy re-starting of an engine without driving a hydraulic actuator, whereby fuel consumption and carbon dioxide emission are reduced.SOLUTION: The working machine comprises a hydraulic pump 42 driven by an engine 40, hydraulic actuators 21, 22, 23, 31, 32, and a capacitor 61 for storing electricity when a generator motor 44 is in a power generation mode and for supplying the electricity when the generator motor 44 is in an electrically driven mode. The working machine whose hydraulic actuator is run by operating levers 50, 70 also includes: idling stop control means 110 for stopping idling operation of the engine 40 when a stop condition is met; and engine re-start control means 120 for allowing the engine 40 to be re-started under a condition that a PPC lock lever 79 is disposed in a retreated position when a start command is output from an engine re-start switch 77 in a state that the engine 40 is stopped by the idling stop control means 110.

Description

  The present invention relates to a hydraulic pump driven by an engine, a hydraulic actuator driven by pressure oil discharged from the hydraulic pump, a generator motor linked to an output system of the engine, and a generator motor that generates power by the engine And a power storage means for supplying electric power when the generator motor operates electrically, and a hydraulic machine is operated by operating an operation lever.

  Conventionally, even in a working machine in which a hydraulic pump is driven by an engine and a hydraulic actuator for a work machine is operated by pressure oil discharged from the hydraulic pump, unnecessary idling operation of the engine is stopped. There is something. For example, Japanese Patent Application Laid-Open No. H10-228707 discloses that the idling operation of the engine is stopped when a state in which the working machine is not operated exceeds a set time. According to such a work machine, it is possible to reduce the fuel consumption and the amount of carbon dioxide to be discharged.

JP 2003-65097 A

  By the way, in the thing of patent document 1 mentioned above, when an operation lever is operated from the state which the idling driving | operation of the engine was stopped, the engine is restarted. In other words, when the operator operates the operation lever to carry out the construction work, the hydraulic oil is supplied from the hydraulic pump to the hydraulic actuator by restarting the engine, and the desired construction work can be performed quickly. Become. However, in the above-described means, when the operator touches the operation lever when getting on and off the vehicle, there is a problem that the hydraulic actuator is driven by restarting the engine.

  In view of the above circumstances, an object of the present invention is to provide a work machine that can facilitate engine restart and solve the above-described problems.

  In order to achieve the above object, a work machine according to the present invention includes a hydraulic pump driven by an engine, a hydraulic actuator driven by pressure oil discharged from the hydraulic pump, and power generation linked to an engine output system. An electric motor and an electric storage unit that stores electric power when the generator motor is operated by the engine while supplying electric power when the generator motor is electrically operated, and operates the hydraulic actuator by operating an operation lever In such a working machine, when the engine is running, idling stop control means for stopping the idling operation of the engine when a predetermined stop condition is satisfied, and when the shut-off operation is performed, the hydraulic pressure supply system is shut off Stops operation of the hydraulic actuator regardless of the operation of the operation lever. On the other hand, when a release operation is performed, a hydraulic control operation means that activates the hydraulic actuator in accordance with the operation of the operation lever by applying a hydraulic pressure to the hydraulic pressure supply system, and a start operation is performed. Engine start operation means for outputting an engine start command when the engine is stopped, and the hydraulic control operation means is shut off when a start command is output from the engine start operation means in a state where the engine is stopped by the idling stop control means. Engine restart control means for permitting restart of the engine on the condition that the engine is operated, the engine restart control means after the engine is restarted until a predetermined workable condition is satisfied During this period, the hydraulic actuator is shut off to keep the hydraulic actuator in a stopped state. Characterized in that it comprises a part.

  Further, according to the present invention, in the above-described work machine, the lock state monitoring unit holds the hydraulic control operation unit in a shut-off state until a predetermined workable condition is satisfied after the engine is restarted. When the hydraulic pressure control operating means is held in the shut-off state by the control signal from the lock state monitoring unit, the hydraulic control operation means holds the shut-off state even if the release operation is performed. To do.

  Further, according to the present invention, in the work machine described above, the lock state monitoring unit holds the hydraulic actuator in an operation stopped state until the engine speed after restart rises to a predetermined workable speed. It is characterized by that.

  Further, according to the present invention, in the work machine described above, the lock state monitoring unit holds the hydraulic actuator in an operation stopped state until an elapsed time after restart reaches a predetermined workable time. And

  Further, the present invention is the work machine described above, wherein the engine start operation means has a push button portion on the operation lever, and when the push button portion is pressed, the operation signal is sent to the engine restart control means. It is a switch that outputs to

  According to the present invention, the restart of the engine is permitted on condition that the hydraulic control operating means for holding the hydraulic actuator in the operation stop state is shut off regardless of the operation of the operation lever. If the hydraulic control operation means is shut off when a start command is output from the engine start operation means, the engine restarts even if the operator touches the operation lever when getting on and off Will be. As a result, the engine restart can be facilitated without driving the hydraulic actuator, and the fuel consumption and the amount of carbon dioxide to be discharged can be reduced.

FIG. 1 is a diagram showing a configuration example of a work machine according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing an upper end portion of an operation lever applied to the work machine shown in FIG. FIG. 3 is a flowchart showing the contents of the idling stop process performed by the main controller shown in FIG. FIG. 4 is a flowchart showing the contents of the engine restart process performed by the main controller shown in FIG. FIG. 5 is a flowchart showing the contents of the assist process shown in FIG. FIG. 6 is a flowchart showing the contents of the machine operation stop cancellation process shown in FIG. FIG. 7 is a timing diagram showing the operation position of the PPC lock lever, the operation stroke of the operation lever, the engine speed, the countdown display, the state of the pilot hydraulic pressure cut-off valve, the operation state of the rotating light and the alarm buzzer in the work machine shown in FIG. It is a chart. FIG. 8 is a timing diagram showing the operation position of the PPC lock lever, the operation stroke of the operation lever, the engine speed, the countdown display, the state of the pilot hydraulic pressure cut-off valve, the operation state of the rotating light and the alarm buzzer in the work machine shown in FIG. It is a chart and the extension switch is turned on.

  Exemplary embodiments of a work machine according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 shows a work machine according to an embodiment of the present invention. The work machine illustrated here is for performing construction work such as a hydraulic excavator, and includes a lower traveling body 1 and an upper swing body 2. The lower traveling body 1 travels through left and right crawler belts (not shown). The upper revolving unit 2 is disposed so as to be able to turn with respect to the lower traveling unit 1 by a turning machinery 3 configured between the upper revolving unit 1 and the lower traveling unit 1. Although not shown in the figure, the turning machinery 3 is configured to include, for example, a turning circle and a pinion that meshes with the turning circle, and the pinion is driven by the turning electric motor 10 that is an electric actuator. Thus, the upper swing body 2 can be swung with respect to the lower travel body 1, while when the swing brake (locking means) 11 is operated, the upper swing body 2 is swung with respect to the lower travel body 1. Can be blocked.

  In the working machine, the working machine unit 20 is provided on the upper swing body 2, while the traveling unit 30 is provided on the lower traveling body 1. The work machine unit 20 is for performing construction work such as excavation and loading. In the work machine according to the present embodiment, a work machine unit 20 having an arm at the tip of the boom and a bucket at the tip of the arm is applied. The work machine unit 20 includes a boom cylinder 21, an arm cylinder 22, and a bucket cylinder 23, and operates the boom, arm, and bucket by appropriately supplying pressure oil to the work machine hydraulic actuators 21, 22, and 23. Can be made.

  The traveling unit 30 is for individually driving the crawler belts of the lower traveling body 1. The traveling unit 30 of the present embodiment includes a right traveling motor 31 and a left traveling motor 32, and the crawler belt can be driven by appropriately supplying pressure oil to the traveling hydraulic actuators 31 and 32.

  The work machine further includes an engine 40 serving as a prime mover, and a hydraulic pump 42, a starter 43, and a generator motor 44 connected to the output shaft of the engine 40 via a PTO (Power Take Off) 41.

  The engine 40 is a diesel engine whose output is controlled by adjusting the amount of fuel injected into the cylinder. The fuel injection amount can be adjusted by giving a control signal from a main controller 100 described later to an engine controller 45 attached to the engine 40. The engine 40 includes an oil temperature sensor 46. The oil temperature sensor 46 detects the temperature of the lubricating oil circulating inside the engine 40 and outputs the detection result to the main controller 100 described later.

  The hydraulic pump 42 is of a variable capacity type using the engine 40 as a drive source. The capacity of the hydraulic pump 42 can be changed by giving a control signal to the pump control valve 47 from the main controller 100 described later. The hydraulic pump 42 can supply pressure oil to the boom cylinder 21, arm cylinder 22, bucket cylinder 23, right travel motor 31, and left travel motor 32 described above when the engine 40 is in operation. .

  A pressure sensor 48 and operation valves 24, 25, 26, 33, 34 are provided in the pressure oil supply passages from the hydraulic pump 42 to the respective hydraulic actuators 21, 22, 23, 31, 32. The pressure sensor 48 detects the pressure of the pressure oil flowing through the supply passage, and outputs the detection result to the main controller 100 described later.

  The operation valves 24, 25, 26, 33, and 34 are used for the boom cylinder 21, the arm cylinder 22, the bucket cylinder 23, the right traveling motor 31, and the left traveling motor 32, respectively. The valve 26, the right travel operation valve 33, and the left travel operation valve 34 are individually provided, and the respective hydraulic actuators 21, 22 are supplied from the hydraulic pump 42 by the pilot hydraulic pressure that is supplied according to the operation of the hydraulic operation lever 50. The pressure oil supply control to 23, 31, 32 is performed.

  The hydraulic operation lever 50 is an input device disposed at a position where the operator can operate the driver seat of the upper swing body 2. The hydraulic operation lever 50 is interposed between pilot oil passages extending from the hydraulic pump 42 to the respective hydraulic actuators 21, 22, 23, 31, 32, and allows pilot hydraulic pressures corresponding to the operation direction and operation amount to be individually set. In addition to being provided to the operation valves 24, 25, 26, 33, and 34, an operation signal corresponding to the operation direction and the operation amount can be output to the main controller 100 described later through the attached potentiometer 51.

  A pilot hydraulic pressure cutoff valve 52 is provided in the pilot oil path from the hydraulic pump 42 to the hydraulic operation lever 50. The pilot hydraulic pressure cutoff valve 52 is operated by a control signal from the main controller 100 described later, and intermittently supplies pressure oil from the hydraulic pump 42 to the hydraulic operation lever 50. When the pilot hydraulic pressure cut-off valve 52 is in the cut-off state, the supply of pressure oil from the hydraulic pump 42 to the hydraulic pressure control lever 50 is cut off, and the operation valves 24, 25, 26, 33, and 34 are in an operation stop state.

  The starter 43 is an electric motor that is rotationally driven when a drive signal is given from the main controller 100 described later.

  The generator motor 44 is switched between a power generation operation and an electric operation under the control of the generator motor controller 60. The generator motor controller 60 switches the operation of the generator motor 44 in accordance with a control signal from the main controller 100 described later. When the generator motor 44 performs a power generation operation, the generator motor controller 60 stores the power generated by the generator motor 44 in the battery (storage means) 61 or the above-described turning electric motor via the turning controller (power supply control means) 62. On the other hand, when the generator motor 44 is electrically operated, the power stored in the battery 61 is supplied to the generator motor 44. The battery 61 is constituted by a capacitor or a storage battery, and includes a voltage sensor 63. The voltage sensor 63 detects the storage voltage of the battery 61 and outputs the detection result to the main controller 100 described later.

  The turning controller 62 controls the supply of electric power to the turning electric motor 10 according to the control signal when a control signal is given from the main controller 100 described later.

  The work machine includes a turning operation lever 70, a key switch 71, an air conditioner switch 72, an alarm buzzer 73, a rotating lamp 74, a monitor 75, an extension switch 76, an engine restart switch 77 (engine start operation means), a PPC pressure. A lock switch 78 is provided.

  Similar to the hydraulic operation lever 50, the turning operation lever 70 is an input device for inputting a turning command for the upper turning body 2, and is disposed at a position where the operator can operate the driver seat of the upper turning body 2. . An operation signal indicating the operation direction and the operation amount of the turning operation lever 70 is given to the main controller 100 described later.

  The key switch 71 is a so-called momentary switch means, and is provided at a position where the operator can operate keys in the driver's seat. When the key switch 71 is operated to the ON position with the engine key inserted, an ON signal is output from the key switch 71 to the main controller 100 described later, and power can be supplied from the battery 61. Become. When the engine key is further started from the ON position, a start command for the engine 40 is output to the main controller 100 described later during the start operation. As a result, for example, a drive signal is given to the starter 43 from the main controller 100 described later, and the engine 40 is started. Note that when the starting operation force on the engine key is removed, the key switch 71 returns to the ON position, but an ON signal is continuously output to the main controller 100 described later, so that the operating state of the engine 40 is continued. . Further, when the engine key is turned off, power from a battery (not shown) cannot be supplied, and when the engine 40 is operated, the fuel supply to the engine 40 is cut, so the engine 40 is stopped and the entire work machine is stopped. Can be shut down.

  The air conditioner switch 72 gives the main controller 100 an operation signal for turning on / off the air conditioner compressor 80 connected to the PTO 41 of the engine 40. The alarm buzzer 73 and the rotating lamp 74 are for informing the outside of the work machine by sounding and turning on in response to a drive signal from the main controller 100. The alarm buzzer 73 is arranged at a position where a ringing sound can be heard by a person around the work machine, and the rotating light 74 is provided to a person around the work machine such as the upper part of the cabin of the upper swing body 2. Thus, it is provided at a position where the light from the rotating lamp 74 can be sufficiently visually recognized. The monitor 75 is in-vehicle display means provided at a position where the operator can visually recognize the driver's seat, and performs various displays in accordance with control signals including output data given from the main controller 100 described later.

  The extension switch 76 is for operating when the idling operation of the engine 40 is extended. The engine restart switch 77 is for operating when the engine 40 is restarted. As shown in FIG. 2, the extension switch 76 and the engine restart switch 77 are provided with individual push buttons 76 a and 77 a at the upper end of the hydraulic operation lever 50 or the turning operation lever 70, respectively. When the buttons 76a and 77a are pressed, the respective operation signals are output to the main controller 100 described later. Reference numeral 53 in the figure is a horn switch for ringing the horn.

  The PPC pressure lock switch 78 outputs a control signal for intermittently operating the pilot hydraulic pressure cut-off valve 52 shown in FIG. 1, and is operated by an operator via a PPC lock lever (hydraulic control operation means) 79 provided in the driver's seat. Can be operated. Specifically, the pilot hydraulic pressure cutoff valve 52 is shut off when the PPC lock lever 79 is retracted and the operator can enter and exit the driver's seat (hereinafter referred to as the “retraction position” of the PPC lock lever 79). On the other hand, when the PPC lock lever 79 is moved forward and the operator cannot enter or leave the driver's seat (hereinafter referred to as “the advanced position” of the PPC lock lever 79), the pilot hydraulic pressure cutoff valve 52 is set. It is set to be in an open state. An output signal from the PPC pressure lock switch 78 is given to the main controller 100 described later.

  Further, the work machine includes a main controller 100. The main controller 100 is operated by the electric power from the battery 61 and is based on signals output from the various sensors 46, 48, 63, the various switches 71, 72, 76, 77, 78 and the operation levers 50, 70 described above. The engine 40, the hydraulic pump 42, the starter 43, the generator motor 44, the turning electric motor 10, the turning brake 11, the work machine unit 20, and the traveling unit 30 are driven to perform construction work on the work machine. It has a function to perform overall control.

  For example, when the hydraulic operation lever 50 is operated while the engine 40 is in operation, pilot hydraulic pressure is applied to the operation valves 24, 25, 26, 33, 34 according to the operation of the hydraulic operation lever 50, and each operation valve 24 is operated. , 25, 26, 33, and 34, the pressure oil supplied from the hydraulic pump 42 is controlled, and the work unit 20 and the traveling unit 30 can perform desired operations. During this time, the main controller 100 commands the engine controller 45 for the target engine speed, and controls the fuel injection amount so that the engine controller 45 becomes the target engine speed in accordance with this command.

  The main controller 100 is provided with idling stop control means 110 and engine restart control means 120. The idling stop control means 110 stops the idling operation of the engine 40 when a predetermined stop condition is satisfied while the engine 40 is operating. The engine restart control unit 120 permits restart of the engine 40 when a predetermined restart condition is satisfied in a state where the engine 40 is stopped by the idling stop control unit 110.

  The idling stop control means 110 includes an engine speed control unit 111, an idling stop processing unit 112, a machine operation prohibition unit 113, a countdown display processing unit 114, and a notification processing unit 115.

  The engine speed control unit 111 is configured to operate a hydraulic operation lever 50 and a turning operation lever 70 (hereinafter simply referred to as “operation levers 50 and 70”) when the engine 40 is idling (for example, about 2000 rpm). The operation state is monitored, and when the time during which the operation levers 50 and 70 are held in the neutral state reaches a preset low speed time (T1 second), the rotational speed of the engine 40 is set to a predetermined low speed (for example, about 1050 rpm). A control signal is output to the engine controller 45 in order to decrease the output to the engine controller 45.

  The idling stop processing unit 112 monitors the operation state of the operation levers 50 and 70 when the engine speed control unit 111 reduces the speed of the engine 40 to a low speed, and the operation levers 50 and 70 are in a neutral state. When the held time reaches a preset stop time (T2 seconds), a process of stopping the idling operation of the engine 40 is performed on condition that none of the preset stop prohibition conditions exist.

In the present embodiment, the following are set as stop prohibition conditions.
(1) PPC lock lever 79 is in the retracted position (2) The stored voltage of the battery 61 is less than a preset threshold value (3) When the air conditioner is operating (4) During engine warm-up operation (5) Operation time after engine restart is set in advance Less than

  The reason that the stop prohibition condition is when the PPC lock lever 79 is in the retracted position is that the operator is very likely to leave the driver's seat for a long time, and the engine key is turned off rather than stopping idling operation. This is because it is preferable to shut down the entire work machine.

  The case where the storage voltage of the battery 61 is less than a preset threshold value is set as the stop prohibition condition in order to ensure restartability of the engine 40 after the idling operation is stopped. As will be described later, when the engine is restarted, electric power is required for the assisting action by the starter 43 and the generator motor 44, so it is preferable to set the above threshold value higher.

  The reason that the stop prohibition condition is when the air conditioner is operating and when the engine is warming up is because the respective purposes cannot be achieved when the idling operation is stopped.

  When the operation time after engine restart is less than the preset time, the stop prohibition condition is that the engine 40 is frequently started and stopped, so that the work performance deteriorates and the fuel consumption increases. This is because there is a risk of being invited.

  The idling stop processing unit 112 has a function of extending the stop time when the extension switch 76 is turned on when the engine speed control unit 111 is operating the engine 40 at a low speed. . When the extension switch 76 is repeatedly operated, the idling stop processing unit 112 performs a process of extending the stop time each time the ON switch is operated.

  When the idling stop processing unit 112 stops the idling operation of the engine 40, the machine operation prohibiting unit 113 stops the control signal from the main controller 100 to the turning controller 62 and operates the turning brake 11 to lower the engine 40. The turning of the upper turning body 2 with respect to the traveling body 1 is mechanically blocked. Further, the machine operation prohibiting unit 113 outputs a control signal for maintaining the shut-off state to the pilot hydraulic pressure shut-off valve 52 when the idling stop processing unit 112 has stopped the idling operation of the engine 40. is there. When the pilot hydraulic pressure cutoff valve 52 is held in the cutoff state by the control signal from the machine operation prohibition unit 113, the pilot hydraulic pressure cutoff valve 52 is continuously held in the cutoff state even when the PPC lock lever 79 is operated. .

  The countdown display processing unit 114 outputs display data for performing a countdown display on the monitor 75 when the time until the idling operation stop by the idling stop processing unit 112 is equal to or shorter than a predetermined time (T3 seconds). It is. For example, the countdown display processing unit 114 outputs display data to the monitor 75 when the time until the idling operation stop is 10 seconds, “10 seconds until the idling operation stops”, “9 seconds until the idling operation stops”. ... and so on until the idling operation is stopped. When the time until the idling operation stop is 10 seconds or longer by the extension switch 76 described above, the countdown display is temporarily stopped, and the process of restarting the countdown display is performed when it becomes 10 seconds again.

  The notification processing unit 115 sounds the alarm buzzer 73 when the idling stop processing unit 112 stops the idling operation of the engine 40 and turns on the rotating lamp 74 so that the idling operation is performed to the outside of the work machine. Informs that the vehicle is stopped.

In addition, the notification processing unit 115 outputs notification data to the monitor 75 for notification when the following conditions are satisfied.
(1) The PPC lock lever 79 moves to the advanced position (2) A predetermined time has elapsed after the idling operation is stopped (3) The stored voltage of the battery 61 is less than a preset threshold value

  The display on the monitor 75 under these conditions is to prevent the work machine from being left unattended due to forgetting to remove the engine key while the idling operation is stopped.

  On the other hand, the engine restart control unit 120 includes a restart processing unit 121, a lock state monitoring unit 122, and a start assist control unit 123.

  When the engine restart switch 77 is turned on in the state where the idling stop control means 110 stops the idling operation of the engine 40, the restart processing unit 121 has the PPC lock lever 79 disposed at the retracted position. On the condition, restart permission of the engine 40 is output to the starter 43 and the engine controller 45. In addition, when the engine 40 is restarted, the restart processing unit 121 first operates with a first rotation speed (for example, about 1000 rpm) as an upper limit, and then moves the PPC lock lever 79 to the advanced position to pilot the engine. When the hydraulic shutoff valve 52 shifts to an open state, a process for increasing the engine 40 to a second rotational speed (for example, about 2000 rpm) is performed.

  The lock state monitoring unit 122 generates a control signal for holding the pilot hydraulic pressure cutoff valve 52 in the cutoff state until the predetermined workable condition is satisfied after the engine 40 is restarted by the restart processing unit 121. Output. When the pilot hydraulic pressure cutoff valve 52 is held in the cutoff state by the control signal from the lock state monitoring unit 122, the pilot hydraulic pressure cutoff valve 52 does not operate even when the PPC lock lever 79 is operated. Thus, the shut-off state is maintained. In the present embodiment, when the speed of the restarted engine 40 increases to a preset work speed (for example, about 700 rpm), the processing is performed assuming that the workable condition is satisfied.

  The start assist control unit 123 drives the starter 43 in response to the restart permission from the restart processing unit 121, and the engine 40 reaches the predetermined assist end rotation speed when the engine 40 is restarted. Until then, a control signal for electrically operating the generator motor 44 to the generator motor controller 60 is output.

  FIG. 3 is a flowchart showing the content of the idling stop process performed by the idling stop control means 110 of the main controller 100 described above. Hereinafter, the idling stop processing of the work machine will be described with reference to the timing charts of FIGS. 3, 7, and 8 as appropriate. In the following, it is assumed that the PPC lock lever 79 is in the advanced position and the pilot hydraulic pressure cutoff valve 52 is open as shown in FIGS.

  First, when the engine 40 is operated (step S101: Yes), the main controller 100 monitors the operation state of the operation levers 50 and 70 (step S102), and the operation levers 50 and 70 are held in the neutral state. If it is present (step S102: Yes), it is determined whether or not the continuation time reaches the low speed time (T1 seconds) (step S103, step S104, step S105). When the operation levers 50 and 70 are displaced before reaching the low speed time (step S104: No → step S105: Yes), the main controller 100 resets the timer 1 (step S106), and then returns the procedure. End the idling stop process this time. As a result, the engine 40 continues idling operation at a rotational speed of about 2000 rpm.

  On the other hand, when the neutral state of the operation levers 50 and 70 reaches the low speed time (step S104: Yes, t1 → t2 in FIGS. 7 and 8), the timer 1 is cleared (step S107), and then the engine is rotated. A control signal is output to the engine controller 45 in order to reduce the number to the low speed (step S108). As a result, the idling operation of the engine 40 is continued in a state where the engine is decelerated to a low speed, and the fuel consumption is reduced and the amount of carbon dioxide to be discharged is reduced as compared with the case where the idling operation is continued in the previous state. Reduction can be achieved (t2 → in FIGS. 7 and 8).

  Further, the main controller 100 outputs a control signal to the engine controller 45 and simultaneously starts the timer 2 (step S109), and whether or not the neutral state of the operation levers 50 and 70 continues for the stop time (T2 seconds). Is determined (step S110, step S111).

  During this time, the main controller 100 determines whether or not it is the countdown display timing (step S112). If it is the display timing (step S112: Yes, t3 in FIGS. 7 and 8, t5 in FIG. 8), Countdown display is performed via the monitor 75 (step S113, t3 → t4 in FIGS. 7 and 8, t5 → t6 in FIG. 8).

  Further, the main controller 100 monitors whether or not the extension switch 76 is turned on (step S114). If the extension switch 76 is turned on (step S114: Yes, t4 in FIG. 8), the timer 2 is cleared. (Step S115), and the procedure proceeds to Step S109 (t4 → t6 in FIG. 8).

  When the idling operation of the engine 40 is at a low speed and the neutral state of the operation levers 50 and 70 continues for the stop time (step S110: Yes, t4 in FIG. 7, t6 in FIG. 8), the main controller 100 Then, stop processing of the engine 40 is performed on condition that there is no stop prohibition condition (step S116: No → step S117).

  The main controller 100 that has performed the stop process of the engine 40 performs a machine operation stop process (step S118), further performs a notification process (step S119), clears the timer 2, and ends the present idling stop process. (Step S120).

  As a result, unnecessary idling operation of the engine 40 is stopped, so that it is possible to reduce the fuel consumption and the amount of carbon dioxide to be discharged. In this case, since the idling operation of the engine 40 is stopped on the condition that at least the stored voltage of the battery 61 is equal to or higher than a preset threshold value, sufficient power can be secured when the engine 40 is restarted.

  In addition, when the idling operation of the engine 40 is stopped, the control signal for the turning controller 62 is stopped, and the turning brake 11 is operated to mechanically prevent the upper turning body 2 from turning relative to the lower traveling body 1. It becomes a state. Further, the control signal for maintaining the shut-off state for the pilot hydraulic pressure shut-off valve 52 is output. Therefore, even if the operation levers 50 and 70 are erroneously operated while the idling operation is stopped, the turning electric motor 10 and the hydraulic actuators 21, 22, 23, 31, and 32 are not likely to malfunction. The upper swing body 2 does not turn relative to the lower travel body 1, the lower travel body 1 does not travel, and the work machine unit 20 does not operate.

  Further, in a state where the idling operation of the engine 40 is stopped, the rotating lamp 74 is lit and the alarm buzzer 73 is sounding, so the idling operation is being stopped for a person outside the work machine. This can be notified.

  Even in the state where the idling operation of the engine 40 is at a low speed, for example, if the operation levers 50 and 70 are operated according to the will of the operator who visually recognizes the countdown display (step S111: Yes), the timer 2 is cleared. The procedure is returned later (step S121), and the idling stop process this time is finished without stopping the idling operation. Therefore, it is possible to continue the construction work without stopping the idling operation, and there is no possibility that the idling stop process described above will greatly hinder the construction work. Even when the idling operation of the engine 40 is at a low speed, if the stop prohibition condition described above exists, that is, (1) the PPC lock lever 79 is in the retracted position, (2) the stored voltage of the battery 61 Is less than a preset threshold, (3) when the air conditioner is operating, (4) when the engine is in warm-up operation, or (5) the operation time after engine restart is less than the preset time Even if the above is true (step S116: Yes), the procedure is returned after the timer 2 is cleared (step S122), and the idling stop process is terminated without stopping the idling operation. Therefore, (1) when the operator leaves the driver's seat for a long time, the idling operation is not automatically stopped so as to recommend that the engine stop by turning off the key switch 71. (2) The idling operation does not automatically stop under circumstances where it may be difficult to restart the engine. (3) There is no risk of hindering the operation of the air conditioner. (4) There is no risk of hindering engine warm-up operation. (5) It is possible to prevent a situation in which automatic engine stop and automatic restart are frequently performed.

  FIG. 4 is a flowchart showing the contents of the engine restart process performed by the engine restart control means 120 of the main controller 100 described above. Hereinafter, the idling stop processing of the work machine will be described with reference to the timing charts of FIGS. 4, 7, and 8 as appropriate. In the following, as shown at t5 in FIG. 7 or t7 in FIG. 8, the idling operation of the engine 40 is stopped by the idling stop process described above, and the PPC lock lever 79 is in the advanced position. It is assumed that the pilot hydraulic pressure cutoff valve 52 is in a closed state.

  First, when the idling operation of the engine 40 is stopped by the idling stop process (step S201: Yes), the main controller 100 monitors the operation state of the engine restart switch 77 and the PPC lock lever 79 (step S202, step). S203), when the engine restart switch 77 is turned on and the PPC lock lever 79 is located at the retracted position (step S202: Yes → step S203: Yes, t10 in FIGS. 7 and 8), the starter 43 The engine controller 45 outputs a permission to restart the engine 40 (step S204). The restart permission of the engine 40 output to the starter 43 and the engine controller 45 has the first rotation speed as an upper limit. As a result, the starter 43 is driven (step S205), and the engine 40 is restarted with the first rotational speed as the target rotational speed. At the same time as the engine 40 is restarted, the rotating lamp 74 is turned off, and the alarm buzzer 73 stops ringing, and the notification to the surroundings ends.

  When the starter 43 is driven, the main controller 100 simultaneously performs an assist process (step S206). In the assist process, as shown in FIG. 5, the main controller 100 detects the engine speed (step S301), and further determines whether or not the detected engine speed is the required assist speed (step S302). When the rotation speed is required (step S302: Yes), the generator motor 44 is electrically operated (step S303).

  The assist rotational speed determined in step S302 is, for example, the rotational speed at which the rotational speed of the engine 40 is 50 rpm or higher and the absolute value of the difference from the target engine rotational speed is 100 rpm or higher. When the generator motor 44 is electrically operated at the required assist speed, the engine 40 is driven by the torque of the starter 43 + generator motor 44, and the engine 40 is quickly and reliably rotated with the load on the starter 43 reduced. It is possible to rotate to a number.

  When the absolute value of the difference between the engine speed and the target engine speed is less than 100 rpm (step S302: No), the main controller 100 returns the procedure and ends the current assist process.

  In FIG. 4, the main controller 100 that has finished the assist process then performs a machine operation stop cancellation process (step S207). In the machine operation stop cancellation process, as shown in FIG. 6, the main controller 100 first detects the engine speed (step S401), and determines whether or not the detected engine speed is equal to or higher than the work speed (step S401). Step S402). When the engine speed becomes equal to or higher than the work speed (step S402: Yes), the main controller 100 returns the pilot hydraulic pressure shut-off valve 52 held in the shut-off state to the openable state (step S403), with respect to the turning controller 62. The control signal output is resumed (step S404), the operation of the turning brake 11 is released, and the procedure is returned (step S405).

  As a result, as shown in FIG. 4, when the PPC lock lever 79 is moved to the advanced position (step S208: Yes), the pilot hydraulic pressure cutoff valve 52 is opened (step S209), and the hydraulic control lever 50 is operated. In this case, the pilot pressure is applied to the operation valves 24, 25, 26, 33, and 34, and the work machine unit 20 and the traveling unit 30 can be operated again according to the operation of the hydraulic operation lever 50. . Further, when the turning operation lever 70 is operated, a control signal corresponding to the operation of the turning operation lever 70 is output to the turning controller 62, and the upper turning body 2 is turned with respect to the lower traveling body 1. It becomes possible.

  In step S209 of FIG. 4, the main controller 100 that has opened the pilot hydraulic pressure cutoff valve 52 simultaneously outputs a control signal for increasing the rotational speed of the engine 40 to the second rotational speed to the engine controller 45. (Step S210). As a result, the rotational speed of the engine 40 becomes about 2000 rpm, and the working machine returns to the state before the idling operation stop process is performed.

  In the restart process of the engine 40 described above, the restart of the engine 40 is permitted on condition that the PPC lock lever 79 is disposed at the retracted position. Therefore, even when the operator touches the operation levers 50 and 70 when getting on and off, the engine 40 is restarted. This facilitates restart of the engine 40 without driving the hydraulic actuators 21, 22, 23, 31, 32, and can reduce the fuel consumption and the amount of carbon dioxide to be discharged.

  Hereinafter, the idling stop process and the engine restart process described above are repeatedly performed, and it becomes possible to reduce the fuel consumption amount and the carbon dioxide amount to be discharged without causing any trouble in the construction work.

  In the above-described embodiment, the engine restart switch 77 outputs a start command for restarting. However, the engine restart switch 77 is not necessarily required, and the key switch 71 is operated by a key operation. You may comprise so that the start command for a restart may be output.

  Further, in the above-described embodiment, the condition that the rotation speed of the engine 40 becomes equal to or higher than the work rotation speed in the machine operation stop cancellation process shown in FIG. 6 is not necessarily required to be based on the rotation speed of the engine. The machine operation stop cancellation process may be performed on condition that the time after the engine is restarted reaches a preset workable time (for example, 2 seconds).

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper turning body 3 Turning machinery 10 Turning electric motor 11 Turning brake 20 Work machine unit 21, 22, 23, 31, 32 Hydraulic actuator 24, 25, 26, 33, 34 Operation valve 30 Traveling unit 40 Engine 42 hydraulic pump 43 starter 44 generator motor 45 engine controller 50, 70 operation lever 52 pilot hydraulic shutoff valve 60 generator motor controller 61 accumulator 62 swing controller 63 voltage sensor 70 swing operation lever 73 alarm buzzer 74 rotating light 75 monitor 76 extension switch 77 engine Restart switch 78 PPC pressure lock switch 79 PPC lock lever 100 Main controller 110 Idling stop control means 111 Engine speed controller 112 Idling stop Processor 113 machine operation prohibiting unit 114 counts down the display processing unit 115 informing processing unit 120 the engine restart control means 121 restarts processing unit 122 locked state monitoring unit 123 start-up assist controller

Claims (5)

A hydraulic pump driven by an engine;
A hydraulic actuator driven by pressure oil discharged from the hydraulic pump;
A generator motor linked to the engine output system;
The power storage unit is configured to store electric power when the generator motor performs a power generation operation by an engine, and to supply power when the generator motor performs an electric operation, and the hydraulic actuator is operated by operating an operation lever. In work machines,
An idling stop control means for stopping the idling operation of the engine when a predetermined stop condition is satisfied in a state where the engine is operated;
By shutting off the hydraulic pressure supply system when the shut-off operation is performed, the hydraulic actuator is held in an operation stop state regardless of the operation of the operation lever, and when the release operation is performed, the hydraulic pressure is applied to the hydraulic pressure supply system. Hydraulic control operation means for making the hydraulic actuator operable according to the operation of the operation lever,
Engine start operation means for outputting an engine start command when the start operation is performed;
An engine for permitting restart of the engine on condition that the hydraulic control operation means is shut off when a start command is output from the engine start operation means in a state where the engine is stopped by the idling stop control means And restart control means,
The engine restart control means is a lock state monitor that holds the hydraulic actuator in an operation stopped state by shutting off the hydraulic pressure supply system until a predetermined workable condition is satisfied after the engine is restarted. A working machine comprising a section. The lock state monitoring unit outputs a control signal for holding the hydraulic control operation means in a shut-off state until a predetermined workable condition is satisfied after the engine is restarted,
2. The work according to claim 1, wherein when the hydraulic pressure control operation unit is held in a shut-off state by a control signal from the lock state monitoring unit, the hydraulic control operation unit holds the shut-off state even if the release operation is performed. machine.   3. The lock state monitoring unit holds the hydraulic actuator in a stopped state until the engine speed after restart increases to a predetermined workable speed. The working machine described in.   The lock state monitoring unit holds the hydraulic actuator in an operation stopped state until an elapsed time after restart reaches a predetermined workable time. Work machine.   The engine start operation means is a switch having a push button portion on the operation lever, and outputs an operation signal to the engine restart control means when the push button portion is pressed. The work machine according to any one of claims 1 to 4.

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