JP7201836B2 - construction machinery - Google Patents

Description

The present invention relates to a construction machine such as a hydraulic excavator, and more particularly to a construction machine that performs power reduction control to reduce the power output by a power source when an operation lever is not operated.

Japanese Patent Application Laid-Open No. 2002-200300 discloses a technique for performing power reduction control called auto idle control in construction machinery, which reduces the power output by the engine by reducing the number of revolutions of the engine when the control lever is not operated.

Also, as an anti-theft device for construction machinery, a technique of performing authentication based on an input pattern of an operation lever is described in Patent Documents 2 and 3, for example.

WO2018/179313 JP-A-11-140918 JP 2018-016985 A

As described in Patent Document 1, in a construction machine that performs power reduction control (auto idle control) that reduces the power output by the engine, which is the power source, when the control lever is not operated, power is reduced when the control lever is operated. It is common to release the reduction control to allow normal power conditions to be restored. However, when the power reduction control is performed in this way, there is a problem that the control may be canceled without the intention to cancel it, such as when the operation lever is accidentally hit by the hand. .

As a solution to this problem, it is conceivable to apply an authentication technique for an input pattern of an operation lever as described in Patent Documents 2 and 3. By applying such authentication technology, it becomes possible to cancel the power reduction control and return to the normal power state only when there is an intention to cancel the power reduction control.

However, in the case of this method, there is a problem that when returning to the normal power state, it is not possible to smoothly transition to the desired operation. For example, if the set recognition pattern is "push the right lever forward and left hand lever forward", and the intended action is "push the right lever backward and left hand lever right". In this case, it is necessary to return the operating lever to the neutral state after operating the operating lever according to the set operation pattern. For this reason, the operator cannot smoothly transition to the desired operation.

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems, and its object is to be able to perform power reduction control when the operating lever is not operated, and to restore the normal power state when the operating lever is erroneously moved. To provide a construction machine capable of suppressing a return to a normal power state and smoothly transitioning to a desired operation when returning to a normal power state.

In order to solve such problems, the present invention provides a power source, a plurality of actuators that receive the power output from the power source and operate, and a distribution amount of the power to the plurality of actuators according to the operating state . a plurality of operating levers for instructing; a plurality of operating state detection devices for detecting the operating states of the plurality of operating levers ; and a controller for controlling the power source, wherein the plurality of operating levers are connected to the plurality of actuators The controller has first and second operating levers that operate different actuators among them, and the controller performs power reduction control to reduce the power when the non-operating state of the first and second operating levers continues. In the construction machine, the controller controls the operation states of the first and second control levers detected by the operation state detection device in a state in which the power is reduced by the power reduction control . and the second control lever are simultaneously operated, the power reduction control is canceled.

According to the present invention, while the power reduction control is performed when the first and second control levers are not operated, the power reduction control can be canceled by simultaneously operating the first and second control levers in the power reduction state. can. Moreover, if one of the first and second operating levers is erroneously operated, the power reduction control is not canceled and the return to the normal power state can be suppressed. Furthermore, since the power reduction control is canceled simply by simultaneously operating the first and second operating levers in the power reduction state, it is possible to smoothly shift to the desired operation when returning to the normal power state.

1 is a diagram showing the appearance of a construction machine (hydraulic excavator) according to a first embodiment of the present invention; FIG. It is a figure which shows the structure of the drive system in 1st Embodiment. It is a figure explaining the movable direction of the control lever of the control lever apparatus in 1st Embodiment, and the definition of a movable direction. 3 is a diagram showing the configuration of an operation signal system of the drive system in the first embodiment; FIG. 3 is a block diagram showing functions of a controller in the first embodiment; FIG. 3 is a block diagram showing functions of a power calculation unit in the first embodiment; FIG. 4 is a flow chart showing a calculation flow of a first lever operation state determination section in the first embodiment; 4 is a flow chart showing a calculation flow of a second lever operation state determination section in the first embodiment; FIG. 5 is a diagram showing the relationship between the sensor value and the meter-in opening area of the directional control valve in the first embodiment, and also showing the definition of the threshold value of the operating pressure. 4 is a flow chart showing a calculation flow of a first lever operation time measuring section in the first embodiment; 7 is a flow chart showing a calculation flow of a second lever operation time measuring section in the first embodiment; 4 is a flow chart showing a calculation flow of a power reduction determination unit in the first embodiment; 7 is a time chart showing an example of changes in operation pressure and target rotation speed when a lever is operated in the first embodiment; FIG. 5 is a block diagram showing functions of a power calculation section of a controller in a modified example of the first embodiment; FIG. 9 is a flow chart showing a calculation flow of a power reduction determination unit in a modified example of the first embodiment; FIG. It is a figure which shows the structure of the drive system in 2nd Embodiment. FIG. 10 is a block diagram showing functions of a controller in the second embodiment; FIG. FIG. 7 is a block diagram showing functions of a power calculation unit in the second embodiment; FIG. 9 is a flow chart showing a calculation flow of a power reduction determination unit in the second embodiment; It is a figure which shows the modification of the drive system in 2nd Embodiment. It is a figure which shows the structure of the drive system in 3rd Embodiment. FIG. 10 is a diagram showing the configuration of an operation signal system of a drive system according to a third embodiment; FIG. FIG. 12 is a diagram showing the relationship between the tilt of the lever in the front-rear direction and the target rotational speed of the electric motor in the third embodiment; FIG. 12 is a block diagram showing functions of a controller in the third embodiment; FIG. It is a figure explaining the conversion process which the sensor signal conversion part in 3rd Embodiment performs. FIG. 12 is a block diagram showing functions of a power calculation unit in the third embodiment; FIG. FIG. 11 is a flow chart showing a calculation flow of a first lever operation state determination unit in the third embodiment; FIG. It is a flow chart which shows the operation flow of the 2nd lever operation state judgment part in a 3rd embodiment.

An embodiment of the present invention will be described below with reference to the drawings.

<First embodiment>
A first embodiment of the present invention will be described with reference to FIGS. 1 to 13. FIG.

~ Composition ~
First, a hydraulic excavator, which is a representative example of construction machinery according to the first embodiment of the present invention, will be described.

FIG. 1 is a diagram showing the appearance of a hydraulic excavator according to this embodiment.

The hydraulic excavator comprises a lower traveling body 101, an upper revolving body 102 rotatably mounted on the lower traveling body, and a swing-type front working machine attached to the front part of the upper revolving body so as to be rotatable in the vertical direction. 104 , and the front work machine 104 is composed of a boom 111 , an arm 112 and a bucket 113 . The upper revolving body 102 and the lower traveling body 101 are rotatably connected by a revolving ring 215 , and the upper revolving body 102 can be revolved relative to the lower traveling body 101 by rotation of the revolving motor 43 . A swing post 103 is attached to the front portion of the upper revolving body 102, and a front working machine 104 is attached to the swing post 103 so as to be vertically movable. The swing post 103 can rotate horizontally with respect to the upper rotating body 102 by extending and retracting a swing cylinder (not shown). The cylinder 13, the arm cylinder 23, and the bucket cylinder 33 are expanded and contracted so as to be vertically rotatable. On the central frame of the lower traveling body 101, left and right traveling devices 105a and 105b and a blade 106 which moves up and down by extension and contraction of the blade cylinder 3h are attached. The right and left traveling devices 105a and 105b are provided with drive wheels 210a and 210b, idlers 211a and 211b, and tracks 212a and 212b, respectively. It travels by driving.

A cabin 110 forming an operator's cab 108 is installed in the upper slewing body 102. In the operator's cab 108, there is an operator's seat 122, and left and right controls for instructing the driving of the boom cylinder 13, the arm cylinder 23, the bucket cylinder 33, and the slewing motor 43. operating lever devices 114 and 134 are provided.

Next, the drive system mounted on the construction machine (hydraulic excavator) of this embodiment will be described. FIG. 2 is a diagram showing the configuration of the drive system of this embodiment.

In FIG. 2 , the drive system includes an engine 6 (diesel engine), a main hydraulic pump 1 and a pilot pump 51 , and the hydraulic pump 1 and pilot pump 51 are driven by the engine 6 . A hydraulic pump 1 is connected to a pipeline 2 to which a relief valve 3 is attached via a relief pipeline 4 . The downstream side of the relief valve 3 is connected to the tank 5 . A tandem pipeline 8 and a parallel pipeline 9 are connected downstream of the pipeline 2 . Pipe lines 11 , 21 , 31 , and 41 are connected in parallel to the parallel pipe line 9 . Check valves 10, 20, 30 and 40 are arranged in the pipelines 11, 21, 31 and 41, respectively.

A directional control valve 12 is connected downstream of the pipeline 8 and the pipeline 11. The directional control valve 12 is also connected to a bottom pipeline 13B connected to the bottom side chamber of the boom cylinder 13, and to the rod side chamber of the boom cylinder 13. It is connected to the connected rod pipe line 13R, the tank pipe line 13T connected to the tank 5, and the center bypass pipe line 13C.

The directional control valve 12 is driven by the pressure in the pilot line 12b and the pressure in the pilot line 12r. When the pressures in both pilot lines are low, the directional control valve 12 is in the neutral position, the line 8 is connected to the center bypass line 13C, and the other lines are shut off. When the pressure in the pilot line 12b is high, the directional control valve 12 is switched upward in the drawing, the line 11 is connected to the bottom line 13B, the tank line 13T is connected to the rod line 13R, and the line 8 is connected to the center line. Bypass line 13C is blocked. When the pressure in the pilot line 12r is high, the directional control valve 12 is switched downward in the drawing, the line 11 is connected to the rod line 13R, the tank line 13T is connected to the bottom line 13B, and the line 8 is connected to the center line. Bypass line 13C is blocked.

A directional control valve 22 is connected downstream of the pipeline 13C and the pipeline 21 . The directional control valve 22 also has a bottom pipe 23B connected to the bottom side chamber of the arm cylinder 23, a rod pipe 23R connected to the rod side chamber of the arm cylinder 23, and a tank pipe connected to the tank 5. 23T and the center bypass line 23C.

The directional control valve 22 is driven by the pressure in the pilot line 22b and the pressure in the pilot line 22r. When the pressures in both pilot lines are low, the directional control valve 22 is in the neutral position, the center bypass line 13C is connected to the center bypass line 23C, and the other lines are shut off. When the pressure in the pilot line 22b is high, the directional control valve 22 is switched upward in the drawing, the line 21 is connected to the bottom line 23B, the tank line 23T is connected to the rod line 23R, and the center bypass line 13C is connected. and the center bypass line 23C are cut off. When the pressure in the pilot line 22r is high, the directional control valve 22 is switched downward in the drawing, the line 21 is connected to the rod line 23R, the tank line 23T is connected to the bottom line 23B, and the center bypass line 13C is connected. and the center bypass line 23C are cut off.

A directional control valve 32 is connected downstream of the pipe 23C and the pipe 31. The directional control valve 32 is also connected to a bottom pipe 33B connected to the bottom side chamber of the bucket cylinder 33 and the rod side chamber of the bucket cylinder 33. , a tank line 33T connected to the tank 5, and a center bypass line 33C.

Directional control valve 32 is driven by the pressure in pilot line 32b and the pressure in pilot line 32r. When the pressures in both pilot lines are low, the directional control valve 32 is in the neutral position, the center bypass line 23C is connected to the center bypass line 33C, and the other lines are shut off. When the pressure in the pilot line 32b is high, the directional control valve 32 is switched upward in the drawing, the line 31 is connected to the bottom line 33B, the tank line 33T is connected to the rod line 33R, and the center bypass line 23C is connected. and the center bypass line 33C are cut off. When the pressure in the pilot line 32r is high, the directional control valve 32 is switched downward in the drawing, the line 31 is connected to the rod line 33R, the tank line 33T is connected to the bottom line 33B, and the center bypass line 23C is connected. and the center bypass line 33C are cut off.

A directional control valve 42 is connected downstream of the pipeline 33C and the pipeline 41. The directional control valve 42 is also connected to the left rotation pipeline 43L connected to the left rotation side chamber of the swing motor 43, and to the rotation motor 43. It is connected to a right rotation pipeline 43R connected to the right rotation side chamber, a tank pipeline 43T connected to the tank 5, and a center bypass pipeline 43C. The center bypass line 43C is connected to the tank 5.

The directional control valve 42 is driven by the pressure in the pilot line 42l and the pressure in the pilot line 42r. When the pressures in both pilot lines are low, the directional control valve 42 is in the neutral position, the center bypass line 33C is connected to the center bypass line 43C, and the other lines are shut off. When the pressure in the pilot line 42l is high, the directional control valve 42 is switched upward in the drawing, the line 41 is connected to the left rotation line 43L, the tank line 43T is connected to the right rotation line 43R, and the center bypass line is connected. Line 33C and center bypass line 43C are blocked. When the pressure in the pilot line 42r is high, the directional control valve 42 is switched downward in the drawing, the line 41 is connected to the right rotation line 43R, the tank line 43T is connected to the left rotation line 43L, and the center bypass line is connected. Line 33C and center bypass line 43C are blocked.

Pilot pump 51 is connected to pilot line 52 . Downstream from the pilot line 52 will be described later with reference to FIG.

Although not shown, the hydraulic drive system is provided with similar directional control valves for the travel motors 3f, 3g, blade cylinders 3h and swing cylinders (not shown) shown in FIG. can be performed.

Here, the engine 6 and the hydraulic pump 1 form a power source, and the boom cylinder 13, the arm cylinder 23, the bucket cylinder 33, and the swing motor 43 form a plurality of actuators that receive power output from the power source. The operating lever devices 114, 134 have right and left operating levers 14, 34 (first and second operating levers) for instructing power distribution amounts to a plurality of actuators, respectively. Power is distributed to a plurality of actuators based on the instructions of the operating levers 14,34.

Next, the configuration of the operation signal system of the drive system will be described with reference to FIGS. 3 and 4. FIG.
3A and 3B are diagrams for explaining the movable directions of the operating levers of the operating lever devices 114 and 134 in the first embodiment and the definition of the movable directions.

As described with reference to FIG. 1, right and left operating lever devices 114 and 134 are installed in the operator's cab 108 of the hydraulic excavator. , the operating lever 34 (second operating lever) of the operating lever device 134 is operated. The operating lever devices 114, 134 can operate two actuators with one operating lever 14 or 34, respectively. The operation levers 14 and 34 can be operated from their neutral positions, and the operation of the operation lever 14 in the forward direction 14b and the rearward direction 14r corresponds to the boom lowering and boom raising operations of the boom cylinder 13, and the rightward direction of the operating lever 14. 24r and leftward 24b operations correspond to bucket dumping and bucket crowding operations of the bucket cylinder 33, and rightward 34b and leftward 34r operations of the control lever 34 correspond to arm crowding and arm dumping operations of the arm cylinder 23. The operation of the operating lever 34 in the forward direction 44l and the rearward direction 44r corresponds to the right-turning and left-turning operations of the turning motor 43. As shown in FIG. In this specification, forward, rearward, rightward, and leftward directions refer to the forward, rearward, rightward, and leftward directions of the upper revolving body 102, which is the vehicle body.

As described above, the operating levers 14, 34 of the operating lever devices 114, 134 can be operated in multiple directions from the neutral position, and the actuators (boom cylinder 13, arm cylinder 23, bucket cylinder 33, swing motor 43) different actuators.

FIG. 4 is a diagram showing the configuration of the operation signal system of the drive system.

4, the operating lever devices 114 and 134 are of a hydraulic pilot type, and the operating lever device 114 has boom pilot valves 15b and 15r and bucket pilot valves 25b and 25r driven by the operating lever 14. , the operating lever device 134 has pilot valves 35b, 35r for arms driven by the operating lever 34 and pilot valves 45l, 45r for turning. In the following description, the operation lever may simply be called "lever".

Pipelines 19 , 29 , 39 , 49 and a relief valve 53 are connected in parallel downstream of the pilot line 52 . A tank 5 is connected downstream of the relief valve 53 . Throttles 94, 95, 96 and 97 are provided in the pipelines 19, 29, 39 and 49, respectively.

The pilot valve 15b of the operating lever device 114 is connected to the line 19 and to the lines 18 and 16b. The conduit 16b is connected to the pilot conduit 12b (see FIG. 2). A pressure sensor 17b is mounted on the conduit 16b. A conduit 18 is connected to the tank 5 .

When the lever 14 is in the neutral position, the pilot valve 15b connects the pipeline 18 and the pipeline 16b and shuts off the pipeline 19. When the lever 14 is operated in the forward direction 14b, the pilot valve 15b connects the pipeline 19 and the pipeline 16b and shuts off the pipeline 18. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 14 is generated in the conduit 16b.

The pressure sensor 17b measures the pressure in the conduit 16b and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 15r of the operating lever device 114 is connected to the line 19 and to the lines 18 and 16r. The pipeline 16r is connected to the pilot pipeline 12r (see FIG. 2). A pressure sensor 17r is mounted on the conduit 16r. A conduit 18 is connected to the tank 5 .

When the lever 14 is in the neutral position, the pilot valve 15r connects the pipeline 18 and the pipeline 16r and shuts off the pipeline 19. When the lever 14 is operated in the rearward direction 14r, the pilot valve 15r connects the pipeline 19 and the pipeline 16r and shuts off the pipeline 18. At this time, a pressure corresponding to the amount of operation of the lever 14 is generated in the conduit 16r.

The pressure sensor 17r measures the pressure in the conduit 16r and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 25b of the operating lever device 114 is connected to the line 29 and to the lines 28 and 26b. The conduit 26b is connected to the pilot conduit 32b (see FIG. 2). A pressure sensor 27b is mounted on the conduit 26b. A conduit 28 is connected to the tank 5 .

When the lever 14 is in the neutral position, the pilot valve 25b connects the pipeline 28 and the pipeline 26b and shuts off the pipeline 29. When the lever 14 is operated in the left direction 24b, the pilot valve 25b connects the pipeline 29 and the pipeline 26b and shuts off the pipeline 28. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 14 is generated in the conduit 26b.

The pressure sensor 27b measures the pressure in the conduit 26b and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 25r of the operating lever device 114 is connected to the line 29 and to the lines 28 and 26r. The conduit 26r is connected to the pilot conduit 32r (see FIG. 2). A pressure sensor 27r is mounted on the conduit 26r. A conduit 28 is connected to the tank 5 .

When the lever 14 is in the neutral position, the pilot valve 25r connects the pipeline 28 and the pipeline 26r and shuts off the pipeline 29. When the lever 14 is operated in the right direction 24r, the pilot valve 25r connects the pipeline 29 and the pipeline 26r and shuts off the pipeline 28. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 14 is generated in the conduit 26r.

The pressure sensor 27r measures the pressure in the conduit 26r and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 35b of the operating lever device 134 is connected to the line 39 and to the lines 38 and 36b. The conduit 36b is connected to the pilot conduit 22b (see FIG. 2). A pressure sensor 37b is mounted on the conduit 36b. A conduit 38 is connected to the tank 5 .

When the lever 34 is in the neutral position, the pilot valve 35b connects the pipeline 38 and the pipeline 36b and shuts off the pipeline 39. When the lever 34 is operated in the right direction 34b, the pilot valve 35b connects the pipeline 39 and the pipeline 36b and shuts off the pipeline 38. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 34 is generated in the conduit 36b.

The pressure sensor 37b measures the pressure in the conduit 36b and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 35r of the operating lever device 134 is connected to the line 39 and to the lines 38 and 36r. The conduit 36r is connected to the pilot conduit 22r (see FIG. 2). A pressure sensor 37r is mounted on the conduit 36r. A conduit 38 is connected to the tank 5 .

When the lever 34 is in the neutral position, the pilot valve 35r connects the pipeline 38 and the pipeline 36r and shuts off the pipeline 39. When the lever 34 is operated in the left direction 34r, the pilot valve 35r connects the pipeline 39 and the pipeline 36r and shuts off the pipeline 38. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 34 is generated in the conduit 36r.

The pressure sensor 37r measures the pressure in the conduit 36r and sends the signal to the controller 50 to which it is electrically connected.

The pilot valve 45l of the operating lever device 134 is connected to the line 49 and to the lines 48 and 46l. The conduit 46l is connected to the pilot conduit 42l (see FIG. 2). A pressure sensor 47l is mounted on the conduit 46l. A conduit 48 is connected to the tank 5 .

When the lever 34 is in the neutral position, the pilot valve 45l connects the pipeline 48 and the pipeline 46l and shuts off the pipeline 49. When the lever 34 is operated in the forward direction 44l, the pilot valve 45l connects the pipeline 49 and the pipeline 46l and shuts off the pipeline 48. At this time, a pressure (operating pressure) corresponding to the amount of operation of the lever 34 is generated in the conduit 46l.

Pressure sensor 47l measures the pressure in line 46l and sends the signal to controller 50 to which it is electrically connected.

The pilot valve 45r of the operating lever device 134 is connected to the line 49 and to the lines 48 and 46r. The conduit 46r is connected to the pilot conduit 42r (see FIG. 2). A pressure sensor 47r is mounted on the conduit 46r. A conduit 48 is connected to the tank 5 .

When the lever 34 is in the neutral position, the pilot valve 45r connects the pipeline 48 and the pipeline 46r and shuts off the pipeline 49. When the lever 34 is operated in the rearward direction 44r, the pilot valve 45r connects the pipeline 49 and the pipeline 46r and shuts off the pipeline 48. At this time, pressure (operation pressure) corresponding to the amount of operation of the lever 34 is generated in the conduit 46r.

The pressure sensor 47r measures the pressure in the conduit 46r and sends the signal to the controller 50 to which it is electrically connected.

The pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r constitute a plurality of operation state detection devices for detecting the operation state of the operation lever devices 114 and 134. FIG. The pressure sensors 17b and 17r constitute a first operating state detection device for detecting the operating state of the operating lever 14 in the front and rear direction, and the pressure sensors 27b and 27r detect the operating state of the operating lever 14 in the right and left directions. The pressure sensors 37b and 37r constitute a third operating state detecting device for detecting the operating state of the operating lever 34 in the right and left directions. A fourth operation state detection device is configured to detect the operation state in the front-rear direction.

Although not shown, the operation signal system includes similar operation lever devices for the travel motors 3f and 3g and the blade cylinder 3h shown in FIG. 1 and the swing cylinder (not shown). In this embodiment, an operation state detection device may be provided for these operation lever devices, and power reduction control, which will be described later, may be performed based on the operation state.

Returning to FIG. 2, the drive system of this embodiment further comprises a controller 50 and a switch 76. FIG.

The controller 50 is electrically connected to the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, 47r, the switch 76 and the target rotational speed indicator 77. The controller 50 receives the measured pressure signals from the pressure sensors 17b to 47r, the signal from the switch 76, and the signal from the target rotation speed indicator 77, and calculates the target rotation speed of the engine 6 based on these signals. Then, a command signal, which is a power command value, is transmitted to the rotation speed control device 7 of the engine 6 electrically connected to the controller 50 . The rotation speed control device 7 controls the engine 6 so as to achieve the target rotation speed.

The switch 76 is a switch for switching whether to set the power reduction control mode by transmitting an ON or OFF signal to the controller 50. When the signal of the switch 76 is OFF, the power reduction control mode is canceled and all The driving power of the engine 6 is not reduced even if the operation lever of is in a non-operating state.

Next, functions of the controller 50 in the first embodiment will be described. FIG. 5 is a block diagram showing functions of the controller 50. As shown in FIG.

In FIG. 5, the controller 50 has the functions of a sensor signal conversion section 50a, a constant/table storage section 50b, and a power calculation section 50c.

The sensor signal converter 50a receives signals sent from the pressure sensors 17b to 47r and the switch 76 and converts them into pressure information and switch flag information. The sensor signal converter 50a transmits the converted pressure information and switch flag information to the power calculator 50c. The pressure information converted by the sensor signal converter 50a is converted into sensor values P17b(t), P17r(t), P27b(t), P27r(t), P37b(t), P37r(t), P47l(t), P47r(t), and the switch information converted by the sensor signal converter 50a is called switch flag Fsw(t). The pressure information converted by the sensor signal converter 50a is the pressure generated in the pipelines 16b-46r by driving the pilot valves 15b-45r, and the sensor values P17b(t), P17r(t), P27b( t), P27r(t), P37b(t), P37r(t), P47l(t), and P47r(t) are sometimes called "operation pressures". It is also assumed that Fsw(t)=true (valid) when the switch 76 is ON, and Fsw(t)=false (invalid) when the switch 76 is OFF.

The constant/table storage unit 50b stores constants and tables required for calculation, and transmits the information thereof to the power calculation unit 50c.

The power calculation unit 50c receives pressure information and switch flag information sent from the sensor signal conversion unit 50a, target rotation speed information sent from the target rotation speed indicator 77, and constants sent from the constant/table storage unit 50b. Information and table information are received, and the target rotation speed of the engine 6 is calculated. Then, the power calculation unit 50 c outputs the target rotation speed to the rotation speed control device 7 .

Next, functions of the power calculation unit 50c in the first embodiment will be described. FIG. 6 is a block diagram showing functions of the power calculation unit 50c. It is assumed that the sampling time of the controller 50 is Δt.

In FIG. 6, the power calculation unit 50c includes a first lever operation state determination unit 50c-1, a second lever operation state determination unit 50c-2, a first lever operation time measurement unit 50c-3, and a second lever operation time measurement unit. 50c-4, a power reduction determination unit 50c-5, and a delay element 50c-6.

The first lever operation state determination unit 50c-1 determines whether or not the lever 14 is being operated based on the sensor values P17b(t), P17r(t), P27b(t), and P27r(t). Output the operation flag F14(t). The first lever operation state determination unit 50c-1 sets the first lever non-operation flag F14(t) to true when it determines that the lever 14 is not operated, and sets the first lever non-operation flag F14(t) to true when it determines that the lever 14 is operated. Set the operation flag F14(t) to false respectively. This flag information is sent to the first lever operation time measurement section 50c-3 and the power reduction determination section 50c-5.

The second lever operation state determination unit 50c-2 determines whether or not the lever 34 is being operated based on the sensor values P37b(t), P37r(t), P47l(t), and P47r(t). Output the operation flag F34(t). The second lever operation state determination unit 50c-2 sets the second lever non-operation flag F34(t) to true when it determines that the lever 34 is not operated, and sets the second lever non-operation flag F34(t) to true when it determines that the lever 34 is operated. Set the operation flag F34(t) to false respectively. This flag information is sent to the second lever operation time measurement section 50c-4 and the power reduction determination section 50c-5.

The first lever operation time measurement unit 50c-3 measures the first lever non-operation time Tu14(t) and the first lever operation time Tc14(t). These time information are transmitted to the power reduction determination unit 50c-5.

The second lever operation time measuring unit 50c-4 measures the second lever non-operation time Tu34(t) and the second lever operation time Tc34(t). These time information are transmitted to the power reduction determination unit 50c-5.

Power reduction determination unit 50c-5 uses flag information F14(t), F34(t), time information Tu14(t), Tc14(t), Tu34(t), Tc34(t), and delay element 50c-6 to Based on the power reduction flag F50(t-Δt) and the switch flag Fsw(t) generated one step before, it is determined whether or not to reduce the target rotation speed. The target rotation speed and the power reduction flag F50(t) are output from the target rotation speed. The power reduction determination unit 50c-5 sets the power reduction flag F50(t) to true when determining to reduce the target rotation speed, and sets the power reduction flag F50(t) to false when determining not to reduce the target rotation speed. do.

Next, the function of the first lever operation state determination section 50c-1 in the first embodiment will be described. FIG. 7 is a flow chart showing the calculation flow of the first lever operation state determining section 50c-1 of FIG. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

At step S101, the calculation of the first lever operation state determination section 50c-1 is started.

In step S102, the first lever operation state determination section 50c-1 determines whether the sensor value P17b(t) is equal to or less than the threshold value Pth. If the sensor value P17b(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S103. If the sensor value P17b(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S107.

In step S103, the first lever operation state determination unit 50c-1 determines whether the sensor value P17r(t) is equal to or less than the threshold value Pth. If the sensor value P17r(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S104. If the sensor value P17r(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S107.

In step S104, the first lever operation state determination section 50c-1 determines whether the sensor value P27b(t) is equal to or less than the threshold value Pth. If the sensor value P27b(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S105. If the sensor value P27b(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S107.

In step S105, the first lever operation state determination section 50c-1 determines whether the sensor value P27r(t) is equal to or less than the threshold value Pth. If the sensor value P27r(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S106. If the sensor value P27r(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S107.

In step S106, the first lever operation state determination unit 50c-1 determines that the lever 14 is not operated and sets the first lever non-operation flag F14(t) to true. Then, the flag information is transmitted to the first lever operation time measurement section 50c-3 and the power reduction determination section 50c-5.

In step S107, the first lever operation state determination unit 50c-1 determines that the lever 14 is being operated, and sets the first lever non-operation flag F14(t) to false. Then, the flag information is transmitted to the first lever operation time measurement section 50c-3 and the power reduction determination section 50c-5.

Next, the function of the second lever operation state determination section 50c-2 in the first embodiment will be described. FIG. 8 is a flow chart showing the calculation flow of the second lever operation state determining section 50c-2 of FIG. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

At step S201, the calculation of the second lever operation state determination section 50c-2 is started.

In step S202, the second lever operation state determination section 50c-2 determines whether the sensor value P37b(t) is equal to or less than the threshold value Pth. If the sensor value P37b(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S203. If the sensor value P37b(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S207.

In step S203, the second lever operation state determination section 50c-2 determines whether the sensor value P37r(t) is equal to or less than the threshold value Pth. If the sensor value P37r(t) is less than or equal to the threshold value Pth, it is determined as Yes, and the process proceeds to step S204. If the sensor value P37r(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S207.

In step S204, the second lever operation state determination unit 50c-2 determines whether the sensor value P47l(t) is equal to or less than the threshold value Pth. If the sensor value P47l(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S205. If the sensor value P47l(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S207.

In step S205, the second lever operation state determination section 50c-2 determines whether the sensor value P47r(t) is equal to or less than the threshold value Pth. If the sensor value P47r(t) is equal to or less than the threshold value Pth, it is determined as Yes, and the process proceeds to step S206. If the sensor value P47r(t) is greater than the threshold value Pth, the determination is No, and the process proceeds to step S207.

In step S206, the second lever operation state determination unit 50c-2 determines that the lever 34 is not operated, and sets the second lever non-operation flag F34(t) to true. Then, the flag information is transmitted to the second lever operation time measuring section 50c-4 and the power reduction determining section 50c-5.

In step S207, the second lever operation state determination unit 50c-2 determines that the lever 14 is being operated, and sets the second lever non-operation flag F34(t) to false. Then, the flag information is transmitted to the second lever operation time measuring section 50c-4 and the power reduction determining section 50c-5.

The definition of the threshold value Pth of the sensor value described above will be described with reference to FIG. FIG. 9 shows the relationship between the sensor value P17b(t) or P17r(t) and the meter-in opening area of the directional control valve 12. As shown in FIG. Further, the sensor value P17b(t) or P17r(t) is written as "operation pressure".

In FIG. 9, the meter-in opening does not open until the operating pressure P17b(t) or P17r(t) reaches the value of Pth, so the hydraulic cylinder (boom cylinder) 13 does not operate. This relationship is the same for other directional control valves. The operation state determination units 50c-1 and 50c-2 use the pressure value Pth at which the meter-in opening opens as a threshold value.

Next, the function of the first lever operation time measuring section 50c-3 in the first embodiment will be explained. FIG. 10 is a flow chart showing the calculation flow of the first lever operation time measuring section 50c-3 of FIG. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

At step S301, the calculation of the first lever operation time measuring section 50c-3 is started.

In step S302, the first lever operation time measurement unit 50c-3 determines whether the first lever non-operation flag F14(t) is true. If the first lever non-operation flag F14(t) is true, it is determined as Yes, and the process proceeds to step S303. If the first lever non-operation flag F14(t) is false, the determination is No, and the process proceeds to step S304.

In step S303, since the lever 14 is not operated, the first lever operation time measurement unit 50c-3 adds the sampling time Δt to the first lever non-operation time Tu14(t−Δt) one step before. A new first lever non-operation time Tu14(t) is set. Also, the first lever operation time Tc14(t) is set to zero. Then, these pieces of information are transmitted to the power reduction determination section 50c-5.

In step S304, since the lever 14 is operated, the first lever operation time measuring section 50c-3 sets the first lever non-operation time Tu14(t) to zero. Also, the value obtained by adding the sampling time Δt to the first lever operation time Tc14(t−Δt) one step before is set as the new first lever operation time Tc14(t). Then, these pieces of information are transmitted to the power reduction determination section 50c-5.

Next, the function of the second lever operation time measuring section 50c-4 in the first embodiment will be explained. FIG. 11 is a flow chart showing the calculation flow of the second lever operation time measuring section 50c-4 of FIG. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

At step S401, the calculation of the second lever operation time measuring section 50c-4 is started.

In step S402, the second lever operation time measuring unit 50c-4 determines whether the second lever non-operation flag F34(t) is true. If the second lever non-operation flag F34(t) is true, it is determined as Yes, and the process proceeds to step S403. If the second lever non-operation flag F34(t) is false, the determination is No, and the process proceeds to step S404.

In step S403, since the lever 34 is not operated, the second lever operation time measurement unit 50c-4 adds the sampling time Δt to the second lever non-operation time Tu34(t−Δt) one step before. A new second lever non-operation time Tu34(t) is set. Also, the second lever operation time Tc34(t) is set to zero. Then, these pieces of information are transmitted to the power reduction determination section 50c-5.

In step S404, since the lever 34 is operated, the second lever operation time measuring section 50c-4 sets the second lever non-operation time Tu34(t) to zero. Also, a value obtained by adding the sampling time Δt to the second lever operation time Tc34(t−Δt) one step before is set as a new second lever operation time Tc34(t). Then, these pieces of information are transmitted to the power reduction determination section 50c-5.

Next, the function of the power reduction determination section 50c-5 in the first embodiment will be described. FIG. 12 is a flow chart showing the calculation flow of the power reduction determination section 50c-5 of FIG. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

At step S501, the calculation of the power reduction determination section 50c-5 starts.

In step S502, the power reduction determination unit 50c-5 determines whether the switch flag Fsw(t) is true. If the switch flag Fsw(t) is true, the determination is Yes, and the process proceeds to step S503. If the switch flag Fsw(t) is false, the determination is No, and the process proceeds to step S515.

In step S503, the power reduction determination unit 50c-5 preliminarily sets the smaller value of the first lever non-operation time Tu14(t) and the second lever non-operation time Tu34(t) as the time to start the power reduction control. It is determined whether or not the set first predetermined time Tth1 is exceeded. If the smaller value of the first lever no-operation time Tu14(t) and the second lever no-operation time Tu34(t) is greater than or equal to the first predetermined time Tth1, the judgment is Yes, and the process proceeds to step S510. . If the smaller value of the first lever no-operation time Tu14(t) and the second lever no-operation time Tu34(t) is smaller than the first predetermined time Tth1, the determination is No, and the process proceeds to step S504. The first predetermined time Tth1 is, for example, 10 to 15 seconds. If neither of the two levers 14, 34 is operated and the no-operation times Tu14(t), Tu34(t) are equal to or greater than the first predetermined time Tth1, the determination is Yes, and step S510. Power reduction control is performed in (described later). In addition, when at least one of the levers 14 and 34 is operated and the power reduction control is not performed and the lever being operated is returned to the neutral position, the non-operation time Tu14(t) and/or Tu34( Since t) is 0, the determination is No, and the process proceeds to step S504. Furthermore, when at least one of the levers 14 and 34 is operated in the power reduction control state, the non-operation time Tu14(t) and/or Tu34(t) becomes 0, so the determination becomes No, and the step The process proceeds to S504.

In step S504, the power reduction determination unit 50c-5 determines whether the power reduction flag F50(t-Δt) one step before is true. If the power reduction flag F50(t-Δt) is true (if the power reduction control has been in progress until now), the determination is Yes, and the process proceeds to step S505. When the power reduction flag F50(t-Δt) is false (when the power reduction control has been canceled until now), it is determined as No, and the process proceeds to step S515 to continue canceling the power reduction control. (described later).

In step S505, the power reduction determination unit 50c-5 determines whether the first lever non-operation flag F14(t) is true. If the first lever non-operation flag F14(t) is true (if the lever 14 has not been operated), the determination is Yes, and the process proceeds to step S506. If the first lever non-operation flag F14(t) is false (if the lever 14 is being operated), the determination is No, and the process proceeds to step S508.

In step S506, the power reduction determination unit 50c-5 determines whether the second lever non-operation flag F34(t) is true. If the second lever non-operation flag F34(t) is true (if the lever 34 is not operated), the determination is Yes, and the process proceeds to step S510 to perform power reduction control (described later). If the second lever non-operation flag F34(t) is false (if the lever 34 is being operated), the determination is No, and the process proceeds to step S507.

In step S507, the power reduction determination unit 50c-5 determines whether the second lever operation time Tc34(t) is longer than a second predetermined time Tth2 set in advance as a time during which it can be considered that the operator intentionally operated the lever. If Tc34(t) is greater than the second predetermined time Tth2 (when the operation time of the lever 34 exceeds Tth2), a determination of Yes is made in step S507, and the process proceeds to step S511 to cancel the power reduction control ( later). When Tc34(t) is equal to or less than the second predetermined time Tth2 (when the operating time of the lever 34 is less than Tth2), No is determined in step S507, and the process proceeds to step S512 to continue the power reduction control. do. The second predetermined time Tth2 is shorter than the first predetermined time Tth1, eg, 2 to 3 seconds.

In step S508, the power reduction determination unit 50c-5 determines whether the second lever non-operation flag F34(t) is true. If the second lever non-operation flag F34(t) is true (if the lever 34 is not operated), the determination is Yes, and the process proceeds to step S509. If the second lever non-operation flag F34(t) is false (if the lever 34 is being operated), it is determined as No, and the process proceeds to step S515 to cancel the power reduction control (described later).

Here, when it is judged No in step S508, it is judged No in both step S505 and step S508, and the first and second control levers 14 and 34 are simultaneously operated in a state where the power is reduced . This is the case where the first release condition is satisfied (hereinafter referred to as " the first release condition is satisfied ") . In the present embodiment, the power reduction control is canceled when the first cancellation condition that the first and second operating levers 14 and 34 are simultaneously operated is satisfied.

In step S509, the power reduction determination unit 50c-5 determines whether the first lever operation time Tc14(t) is longer than the second predetermined time Tth2. If the first lever operation time Tc14(t) is greater than the second predetermined time Tth2 (the operation time of the lever 14 exceeds Tth2), the determination is Yes, and the process proceeds to step S513 to cancel the power reduction control. (described later). When the first lever operation time Tc14(t) is equal to or less than the second predetermined time Tth2 (when the operation time of the lever 14 is less than Tth2), No is determined, and the process proceeds to step S514 for power reduction control. to continue.

Here, when it is judged No in step S506 and it is judged Yes in step S507, and when it is judged Yes in step S508 and it is judged Yes in step S509, respectively, the power is reduced. , one of the first and second operating levers 14 and 34 is operated, and the second release condition that the operating state of one of the operating levers 14 and 34 continues for the second predetermined time Tth2 is satisfied (hereinafter referred to as " second 2 ) is the case that the release condition is satisfied. In this embodiment, even if the first release condition is not satisfied, one of the first and second operating levers 14 and 34 is operated, and the operating state of the one operating lever is changed to the second operating state. 2 If the second cancellation condition continues for a predetermined time Tth2, the power reduction control is canceled.

In step S510, the power reduction determination section 50c-5 sets the power reduction flag F50(t) to true, and at the same time sets the target rotation speed of the engine 6 to be higher than the normal target rotation speed indicated by the target rotation speed indicating device 77. also reduce Then, the target rotation speed information is transmitted to the rotation speed control device 7 . The rotation speed control device 7 reduces the rotation speed of the engine 6 by reducing the amount of fuel supplied to the engine 6 . In steps S512 and S514, the same processing as in step S510 is performed. Thus, the power reduction determination unit 50c-5 performs power reduction control in steps S510, S512 and S514.

In step S511, the power reduction determination unit 50c-5 sets the power reduction flag F50(t) to false and sets the target rotation speed of the engine 6 to the normal value indicated by the target rotation speed indicating device 77. Then, the target rotation speed information is transmitted to the rotation speed control device 7 . The rotation speed control device 7 increases the rotation speed of the engine 6 by increasing the amount of fuel supplied to the engine 6 . In steps S513 and S515, the same processing as in step S511 is performed. Thus, the power reduction determination section 50c-5 cancels the power reduction control in steps S511 and S513. Further, in step S515, if the power reduction control has not been performed so far, the power reduction control is continued to be released, and if the power reduction control has been performed so far, the power reduction control is released.

Next, an example of transition of the operating pressure and the target rotational speed in the first embodiment will be described with reference to FIG. 13 . FIG. 13 is a time chart showing an example of changes in the operating pressure and the target rotational speed when the levers 14 and 34 are operated. The upper graph in FIG. 13 shows the time change of the operating pressure P17b(t) by the lever 14, the middle graph shows the time change of the operating pressure P37b(t) by the lever 34, and the lower graph shows the time change of the target rotation speed. , respectively. The horizontal axis is time (seconds) in all graphs. The upper graph and the middle graph also show the threshold Pth of the operating pressure.

At time t0, the lever 14 is operated forward 14b and the lever 34 is operated rightward 34b. Therefore, the pressure values of the operation pressure P17b(t) and the operation pressure P37b(t) both exceed the threshold value Pth, and the pressure values of other operation pressures (not shown) are zero. At this time, the process of step S515 in FIG. That is, power reduction control (auto idle control) is canceled.

From time t0 to time t1, both of the operating pressures P17b(t) and P37b(t) are greater than the threshold value Pth. At this time as well, the process of step S515 in FIG. 12 is performed (S502→S503→S504→S515), and the target rotation speed is the normal value Nh.

At time t1, the levers 14 and 34 return to their neutral positions, and both the operating pressures P17b(t) and P37b(t) are smaller than the threshold value Pth. Therefore, the process of step S515 is performed from the time t1 until the first predetermined time Tth1 seconds later, and then the process of step S510 in FIG. , and is set to a small value Nl for power reduction control (auto idle control).

At time t2, the lever 34 is operated and only the operating pressure P37b(t) is greater than the threshold value Pth. At this time, the process of step S512 in FIG. 12 is performed (S502→S503→S504→S505→S506→S507→S512), and the power reduction control is continued. When this state continues for the second predetermined time Tth2 seconds or more and the above-described second release condition is satisfied, the process of step S511 in FIG. number is set to the normal value Nh and the power reduction control is canceled.

If the operation of the lever 34 at this time is an erroneous operation and the lever 34 returns to the neutral position before reaching the second predetermined time Tth2 seconds, the non-operation time Tu34(t) becomes zero. At this time, the judgment in step S503 of FIG. 12 remains No, and the judgment in step S506 becomes Yes. Therefore, the process of step S510 is performed (S502->S503->S504->S505->S506->S510), and the power reduction control is continued.

After that, the operation pressure P37b(t) decreases again at time t2a, and both the operation pressures P17b(t) and P37b(t) become values smaller than the threshold value Pth. When this state continues for the first predetermined time Tth1 seconds or longer, the process of step S510 in FIG. 12 is performed (S502→S503→S510), and the target rotation speed is set to a small value Nl for power reduction control. At time t3, the operating pressures P17b(t) and P37b(t) are simultaneously greater than the threshold value Pth. At this time, the above-described first release condition is satisfied, and the process of step S515 in FIG. 12 is performed (S502→S503→S504→S505→S508→S515), and the target rotation speed is restored to the normal value Nh without delay. is set and the power reduction control is canceled.

As described above, according to the present embodiment, the controller 50 operates the first control levers 14, 34 of the control lever devices 114, 134 at the same time when the power of the engine 6 and the hydraulic pump 1 is reduced. When the cancellation condition is satisfied (S502→S503→S504→S505→S508→S515 in FIG. 12), the controller 50 determines that the operator has an intention to cancel the power reduction, and cancels the power reduction control. . As a result, while the power reduction control is performed when the two operation levers 14 and 34 are not operated, the power reduction control can be canceled by simply operating the two operation levers 14 and 34 simultaneously in the power reduction state. In addition, since the power reduction control is canceled simply by operating the two operating levers 14 and 34 simultaneously in the power reduction state, it is possible to smoothly shift to the desired operation when returning to the normal power state.

On the other hand, when one operating lever is operated, the power reduction control is canceled when the second release condition is satisfied that one operating lever is operated for a time longer than the second predetermined time Tth2 (S502→S503→ S504→S505→S506→S507→S511, or S502→S503→S504→S505→S508→S509→S513). As a result, if one of the control levers is accidentally operated for a short period of time (less than the second predetermined time Tth2), the power reduction control is not canceled and the return to the normal power control state is avoided. be able to. Further, since the power reduction control is canceled simply by operating one operation lever continuously for the second predetermined time Tth2 or more, it is possible to smoothly shift to the desired operation when returning to the normal power state.

<Modification 1>
In the first embodiment, as described above, the controller 50 operates when the two operating levers 14, 34 of the operating lever devices 114, 134 are simultaneously operated while the power of the engine 6 and the hydraulic pump 1 is reduced. and when one operation lever is continuously operated for the second predetermined time Tth2 or more, the power reduction control is canceled. However, the power reduction control is canceled only when either one of them, for example, the two operation levers 14, 34 of the operation lever devices 114, 134 are simultaneously operated in the power reduction state of the engine 6 and the hydraulic pump 1. The controller 50 may be configured as follows. Even in this case, as described above, the power reduction control can be performed when the control lever is not operated, and the return to the normal power state when the control lever is accidentally moved can be suppressed, and the normal power state can be controlled. It is possible to obtain the effect of being able to smoothly transition to the desired action when returning to the state.

<Modification 2>
In the first embodiment, the controller 50 controls the power limit control even when the operating lever 34 is operating the swing motor 43 when the first release condition that the operating levers 14 and 34 are simultaneously operated is satisfied. was released. However, even if the first release condition that the operating levers 14 and 34 are simultaneously operated is satisfied, if the operating lever 34 operates the swing motor 43, the power limit control is not released, and the operating lever 34 is operated by the swing motor 43. may be configured to release the power reduction control only when the is not operating.

Such a modification will be described with reference to FIGS. 14 and 15. FIG.

FIG. 14 is a block diagram similar to FIG. 6 showing the functions of the power calculation section 50c of the controller 50 in this embodiment.

In FIG. 14, the power calculation unit 50c (see FIG. 5) has a power reduction determination unit 50c-5D. Operation time Tu14(t), first lever operation time Tc14(t), second lever non-operation flag F34(t), second lever non-operation time Tu34(t), second lever operation time Tc34(t), switch In addition to the flag Fsw(t), the sensor values P47l(t) of the pressure sensors 47l and 47r for detecting the operating state of the operating lever 34 in the front-rear direction corresponding to the operation instructions of turning the turning motor 43 to the right and left, P47r(t) is entered.

FIG. 15 is a flow chart showing the calculation flow of the power reduction determining section 50c-5D of FIG.

In FIG. 15, step S530 is added to the calculation flow of the power reduction determination unit 50c-5D. If there is, it is determined as No, and the process proceeds to step S530.

In step S530, the power reduction determination unit 50c-5D determines whether the sensor value P47l(t) is greater than the threshold value Pth and whether the sensor value P47r(t) is greater than the threshold value Pth. When it is determined that either one of the sensor value P47l(t) and the sensor value P47r(t) is greater than the threshold value Pth (when the operation lever 34 operates the turning motor 43), the process proceeds to step S514. When it is determined that neither the sensor value P47l(t) nor the sensor value P47r(t) is greater than the threshold value Pth (when the operation lever 34 does not operate the turning motor 43), the process proceeds to step S515.

In step S514, the power reduction determination unit 50c-5D sets the power reduction flag F50(t) to true, and at the same time reduces the target rotation speed of the engine 6 below the normal value indicated by the target rotation speed indicating device 77. and perform power reduction control. In step S515, the power reduction determination section 50c-5D sets the power reduction flag F50(t) to false and sets the target engine speed of the engine 6 to the normal value indicated by the target speed indicator 77.

As described above, in the present modification, if the determination in step S508 is No, and the first release condition is established in which the first and second operating levers 14 and 34 are simultaneously operated while the power is reduced, step If it is determined No in S530 and the second operating lever 34 does not operate the turning motor 43, the power reduction control is canceled.

In the modified example configured in this way, as in the first embodiment, the return to the normal power state is suppressed when the operation lever is erroneously moved, and when the normal power state is restored, In addition to being able to smoothly transition to the desired operation, when the two operation levers 14 and 34 are operated simultaneously to cancel the power reduction control, the upper rotating body 102 does not rotate, preventing deterioration of operability. can do.

<Modification 3>
In the first embodiment, the operating lever devices 114, 134 are of a hydraulic pilot type with pilot valves, and the operating state detection devices are pressure sensors 17b, 17r, 27b, 27r for detecting the operating pressure generated by the pilot valves. , 37b, 37r, 47l, and 47r have been described, but the operation state detection device may have other configurations. For example, a signal pressure generating line is provided to guide the discharge oil of the pilot pump 51 to the tank 5, and a plurality of signal pressure generating valves are arranged in this signal pressure generating line. The operating state of the operating lever device may be detected by detecting the pressure in the signal pressure generating line that changes according to the operating pressure and by opening or closing the signal pressure generating valve. Even in this case, the pressure sensor detects the operating state of the operating lever devices 114 and 134 in the same manner as the pressure sensor that detects the operating pressure, and the same effect as in the first embodiment can be obtained.

<Second embodiment>
A second embodiment of the present invention will be described with reference to FIGS. 16 to 19. FIG. The description of this embodiment will focus on the differences from the first embodiment, and the description of the same parts as the first embodiment will be omitted.

First, the configuration of the drive system in the second embodiment will be described. FIG. 16 is a diagram showing the configuration of the drive system of this embodiment.

16, the drive system of the second embodiment differs from the first embodiment in that the hydraulic pump 1 is driven by a DC electric motor 60A, which is electrically connected to a battery 62. The electric motor 60A is driven by the power supplied from the battery 62, the battery output from the battery 62 is controlled by the battery output control panel 63, and the battery output control panel 63 functions as the controller 50A. They are electrically connected, and the battery output control panel 63 controls the output power based on the target battery output information transmitted from the controller 50A.

Here, the battery 62 is a power supply device, and this power supply device and the electric motor 60A constitute a power source.

Next, functions of the controller 50A in the second embodiment will be described. FIG. 17 is a block diagram showing functions of the controller 50A.

In FIG. 17, the controller 50A in the second embodiment differs from the first embodiment in that a power calculation unit 50cA is provided instead of the power calculation unit 50c. It receives the pressure information and switch flags sent from the constant/table storage unit 50b, and the constant information and table information sent from the constant/table storage unit 50b, and calculates the target value of the battery output (target battery output). The target battery output calculated by the power calculation unit 50cA is transmitted to the battery output control panel 63, and the battery output control panel 63 controls the output of the battery 62 based on the value.

Next, the function of the power calculation section 50cA in the second embodiment will be explained. FIG. 18 is a block diagram showing the functions of the power calculation section 50cA.

In FIG. 18, the power calculation section 50cA in the second embodiment differs from the first embodiment in that a power reduction determination section 50c-5A is provided instead of the power reduction determination section 50c-5, and the power reduction determination section 50c-5A is provided. The determination unit 50c-5A is the point that outputs the target battery output. The input of the power reduction determination section 50c-5A is the same as that of the power reduction determination section 50c-5.

Next, the calculation flow of the power reduction determination section 50c-5A in the second embodiment will be described. FIG. 19 is a flow chart showing the calculation flow of the power reduction determination section 50c-5A.

In FIG. 19, the calculation flow of the power reduction determination unit 50c-5A in the second embodiment differs from that in the first embodiment in that the processing of step S516 is performed instead of step S510, and the processing of step S517 is performed instead of step S511. Step S518 instead of step S512, step S519 instead of step S513, step S520 instead of step S514, and step S521 instead of step S515. is.

In step S516, the power reduction determination unit 50c-5A sets the power reduction flag F50(t) to true and at the same time reduces the target battery output from the normal time. Then, the target battery output is transmitted to the battery output control panel 63 . Steps S518 and S520 perform the same processing as step S516.

In step S517, the power reduction determination unit 50c-5A sets the power reduction flag F50(t) to false and sets the target battery output to the normal value. Then, the target battery output is transmitted to the battery output control panel 63 . Steps S519 and S521 perform the same processing as step S517.

In the second embodiment configured as described above, even when the power source is composed of the battery 62 (power supply device), the electric motor 60A, and the hydraulic pump 1, the power source is the same as in the first embodiment. When the first release condition is satisfied that the two operating levers 14 and 34 of the operating lever devices 114 and 134 are simultaneously operated in the power reduction state, or one operating lever is continuously operated for a second predetermined time Tth2 or more. When the second cancellation condition is satisfied, the controller 50 determines that the operator "has an intention to cancel the power reduction", and cancels the power reduction control. As a result, it is possible to perform power reduction control when the control lever is not operated, suppress the return to the normal power state when the control lever is moved by mistake, and when returning to the normal power state, You can smoothly transition to the action you want to perform.

<Modification>
In the second embodiment, the power source of the drive system is composed of the DC electric motor 60A and the hydraulic pump 1, but an AC electric motor may be used instead of the DC electric motor 60A. FIG. 20 shows a modification of such a drive system.

20, the power source of the drive system is composed of an AC electric motor 60B and a hydraulic pump 1. In FIG. The hydraulic pump 1 is driven by an AC electric motor 60B, and the electric motor 60B is controlled by an inverter 61. The inverter 61 is electrically connected to the controller 50 and receives information on the target rotational speed from the controller 50 . The controller 50 performs the same processing as the controller 50 shown in FIG. 5 to calculate the target rotation speed. The inverter 61 is also electrically connected to a battery 62 and receives power to be supplied to the electric motor 60B. Even in such a configuration, the same effects as those of the first and second embodiments can be obtained.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIGS. 21 to 28. FIG. Power reduction in this embodiment is achieved by lowering the potential in the drive system.

First, the configuration of the drive system in the third embodiment will be explained. FIG. 21 is a diagram showing the configuration of the drive system of this embodiment.

In FIG. 21, the controller 50C is electrically connected to an angle sensor 72, an angle sensor 73, an angle sensor 74, an angle sensor 75, and a switch 76, which will be described later. and switch information signals. The controller 50C calculates the target battery output of the battery 62 based on those signals, and transmits the target battery output to the battery output control panel 63 electrically connected to the controller 50C. A battery output control panel 63 controls the battery 62 to achieve the target battery output.

The battery 62 is connected to a positive wire 81 and a negative wire 82 . Inverters 83 , 84 , 85 and 86 are connected in parallel to the positive wire 81 and the negative wire 82 .

The inverter 83 drives an electric motor 87, which in turn drives a cylinder 91 (boom cylinder). The cylinder 91 expands and contracts by converting the rotary motion of the electric motor 87 into linear motion by means of a rack and pinion mechanism or the like. The inverter 83 receives the signal transmitted from the angle sensor 72 and controls the electric motor 87 so that the number of revolutions corresponds to the information.

The inverter 84 drives an electric motor 88, which in turn drives a cylinder 92 (arm cylinder). The cylinder 92 expands and contracts by converting the rotary motion of the electric motor 88 into linear motion by means of a rack and pinion mechanism or the like. The inverter 84 receives the signal transmitted from the angle sensor 73 and controls the electric motor 88 so that the number of revolutions corresponds to the information.

The inverter 85 drives an electric motor 89, which in turn drives a cylinder 93 (bucket cylinder). The cylinder 93 expands and contracts by converting the rotary motion of the electric motor 89 into linear motion by means of a rack and pinion mechanism or the like. The inverter 85 receives the signal transmitted from the angle sensor 74 and controls the electric motor 89 so that the number of revolutions corresponds to the information.

Inverter 86 drives electric motor 90 . The inverter 86 receives the signal transmitted from the angle sensor 75, and controls the electric motor 90 (swing motor) so that the number of revolutions corresponds to the information.

Here, the battery 62 is a power supply device, and this power supply device constitutes a power source. Further, the electric motor 87 and cylinder 91, the electric motor 88 and cylinder 92, the electric motor 89 and cylinder 93, and the electric motor 90 constitute a plurality of actuators that operate by receiving power from the power source. , 86 constitute a power distribution device for distributing power to a plurality of actuators (electric motor 87 and cylinder 91, electric motor 88 and cylinder 92, electric motor 89 and cylinder 93, and electric motor 90). The operation lever devices 314, 334, which will be described later, provide power distribution devices (inverters 83, 84, 85, 86) with a plurality of actuators (electric motor 88 and cylinder 92, electric motor 89 and cylinder 93, and electric motor 90). It instructs the distribution amount of the power.

Next, the configuration of the operation signal system in the third embodiment will be explained using FIGS. 22 and 23. FIG.

FIG. 22 is a diagram showing the configuration of the operation signal system of the drive system in the third embodiment.

In FIG. 22, the operation signal system in the third embodiment differs from the operation signal system in the first embodiment shown in FIG. The difference is that an operation lever device 334 is provided in place of the . The operating lever devices 314 and 334 are of an electric lever type, and the operating lever device 314 includes the lever 14, an angle sensor 72 that outputs angle information in the forward direction 14b and the rearward direction 14r, and an angle sensor 72 that outputs angle information in the left direction 24b and the right direction 24r. and an angle sensor 73 for outputting angle information. The operating lever device 334 has an angle sensor 74 that outputs angle information in the right direction 34b and left direction 34r, and an angle sensor 75 that outputs angle information in the forward direction 44l and backward direction 44r.

The angle sensors 72 , 73 , 74 , 75 constitute a plurality of operating state detection devices for detecting operating states of the operating lever devices 314 , 334 .

The angle sensors 72, 73, 74, 75 are electrically connected to the controller 50C. The angle sensor 72 is also electrically connected to the inverter 83 and transmits angle information. The angle sensor 73 is also electrically connected to the inverter 85 and transmits angle information. The angle sensor 74 is also electrically connected to the inverter 84 and transmits angle information. The angle sensor 75 is also electrically connected to the inverter 86 and transmits angle information.

FIG. 23 is a diagram showing the relationship between the inclination of the lever 14 in the longitudinal direction 14b, 14r and the target rotation speed of the electric motor 87. As shown in FIG. As shown in FIG. 23, as the lever 14 tilts forward 14b, the target number of revolutions of the electric motor 87 increases clockwise. Also, the target rotational speed of the electric motor 87 becomes zero when no operation is performed. As the lever 14 tilts in the rearward direction 14r, the target rotation speed of the electric motor 87 increases in the counterclockwise direction.

When the lever 14 is tilted in the right direction 24r/left direction 24b, when the lever 34 is tilted in the right direction 34b/left direction 34r and in the forward direction 44l/backward direction 44r, the target rotations of the electric motors 88, 89, 90 are similarly set. number changes.

Next, functions of the controller 50C in the third embodiment will be described. FIG. 24 is a block diagram showing functions of the controller 50C.

In FIG. 24, the controller 50C in the third embodiment differs from the second embodiment in that a sensor signal conversion section 50aC is provided instead of the sensor signal conversion section 50a, and a power calculation section 50cC is provided instead of the power calculation section 50cA. The point is that it has

The sensor signal converter 50aC receives signals sent from the angle sensors 72 to 75 and the switch 76 and converts them into angle information and switch flag information. The sensor signal converter 50aC transmits the converted angle information and switch flag information to the power calculator 50cC.

The constant/table storage unit 50b stores constants and tables required for calculation, and transmits them to the power calculation unit 50cC.

The power calculation unit 50cC receives the angle information and switch flag information sent from the sensor signal conversion unit 50aC, and the constant information and table information sent from the constant/table storage unit 50b, and calculates the target battery output of the battery 62. do. Then, the power calculation unit 50cC outputs the target battery output value to the battery output control panel 63. The battery output control board 63 controls the output of the battery 62 based on the value.

The conversion processing of the sensor signal in the sensor signal conversion section 50aC will be described. FIG. 25 is a diagram for explaining conversion processing performed by the sensor signal conversion section 50aC, when the lever 14 is tilted forward 14b or backward 14r.

As shown in FIG. 25, the sensor signal converter 50aC converts the sensor value A72(t) so that it increases as the lever 14 tilts forward 14b. Also, when there is no operation, the sensor value A72(t) is converted to 0. When the lever 14 tilts in the rearward direction 14r, the sensor value A72(t) becomes a negative value. The same applies when the lever 14 is tilted rightward 24r/leftward 24b, and when the lever 34 is tilted rightward 34b/leftward 34r and forward 44l/backward 44r. The sensor value A72(t) is a value corresponding to the target rotational speed of the electric motor 87 in FIG.

Next, the function of the power calculation section 50cC in the third embodiment will be explained. FIG. 26 is a block diagram showing the functions of the power calculation section 50cC. Assume that the sampling time of the controller 50C is Δt.

In FIG. 26, the power calculation unit 50cC in the third embodiment differs from the first embodiment in that the first lever operation state determination unit 50c-1C is used instead of the first lever operation state determination unit 50c-1. a second lever operation state determination unit 50c-2C instead of the second lever operation state determination unit 50c-2; -5C is provided.

Next, the function of the first lever operation state determination section 50c-1C in the third embodiment will be described. FIG. 27 is a flow chart showing the calculation flow of the first lever operation state determination section 50c-1C. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

The calculation flow of the first lever operation state determination section 50c-1C differs from that of the first lever operation state determination section 50c-1 in the first embodiment shown in FIG. The point is that the processing proceeds from step S101 to steps S110 and S111.

In step S110, the first lever operation state determination section 50c-1C determines whether the absolute value of the sensor value A72(t) is smaller than the threshold Ath. If the absolute value of the sensor value A72(t) is smaller than the threshold Ath, it is determined as Yes, and the process proceeds to step S111. If the absolute value of the sensor value A72(t) is equal to or greater than the threshold value Ath, the determination is No, and the process proceeds to step S107.

In step S111, the first lever operation state determination section 50c-1C determines whether the absolute value of the sensor value A73(t) is smaller than the threshold Ath. If the absolute value of the sensor value A73(t) is smaller than the threshold Ath, it is determined as Yes, and the process proceeds to step S106. If the absolute value of the sensor value A73(t) is equal to or greater than the threshold value Ath, the decision is No, and the process proceeds to step S107.

In step S106, the first lever non-operation flag F14(t) is set to true, and in step S107, the first lever non-operation flag F14(t) is set to false. These pieces of flag information are sent to the first lever operation time measurement section 50c-3 and the power reduction determination section 50c-5C.

Next, the function of the second lever operation state determination section 50c-2C in the third embodiment will be described. FIG. 28 is a flow chart showing the calculation flow of the second lever operation state determination section 50c-2C. This operation flow is repeatedly processed every sampling time Δt while the controller 50 is operating, for example.

The calculation flow of the second lever operation state determination section 50c-2C differs from that of the second lever operation state determination section 50c-2 in the first embodiment shown in FIG. The point is that the processing proceeds from step S201 to steps S210 and S211.

In step S210, the second lever operation state determination section 50c-2C determines whether the absolute value of the sensor value A74(t) is smaller than the threshold Ath. If the absolute value of the sensor value A74(t) is smaller than the threshold Ath, it is determined as Yes, and the process proceeds to step S211. If the absolute value of the sensor value A74(t) is equal to or greater than the threshold value Ath, the determination is No, and the process proceeds to step S207.

In step S211, the second lever operation state determination section 50c-2C determines whether the absolute value of the sensor value A75(t) is smaller than the threshold Ath. If the absolute value of the sensor value A75(t) is smaller than the threshold Ath, it is determined as Yes, and the process proceeds to step S206. If the absolute value of the sensor value A75(t) is greater than or equal to the threshold value Ath, the determination is No, and the process proceeds to step S207.

In step S206, the second lever non-operation flag F34(t) is set to true, and in step S207, the second lever non-operation flag F34(t) is set to false. These flag information are sent to the second lever operation time measuring section 50c-4 and the power reduction determining section 50c-5C.

In this way, the first lever operation state determination unit 50c-1C determines whether or not the lever 14 is being operated based on the sensor values A72(t) and A73(t). ). The second lever operation state determination unit 50c-2C determines whether the lever 34 is being operated based on the sensor values A74(t) and A75(t), and outputs the second lever non-operation flag F34(t). do.

The first lever operation time measurement unit 50c-3 measures the first lever non-operation time Tu14(t) and the first lever operation time Tc14(t). These pieces of time information are sent to the power reduction determination section 50c-5C.

The second lever operation time measuring section 50c-4 measures the second lever non-operation time Tu34(t) and the second lever operation time Tc34(t). These pieces of time information are sent to the power reduction determination section 50c-5C.

The power reduction determination unit 50c-5C, similar to the power reduction determination unit 50c-5A of the second embodiment shown in FIG. 18, follows the procedure of the flowchart shown in FIG. Output target battery output and power reduction flag F50(t). The target battery output is sent to the battery output control board 63, and the battery output control board 63 controls the battery 62 so as to achieve the target battery output.

In the third embodiment configured as described above, even if the power source is configured by the battery 62 (power supply device) and the actuator is configured by the electric actuator including the electric motors 87 to 90, the first embodiment can be used. Similarly, when the first release condition is satisfied that the two operating levers 14 and 34 of the operating lever devices 314 and 334 are simultaneously operated in the power reduction state of the power source, or one operating lever is held for a second predetermined time When the second canceling condition that the operation is continued for Tth2 or more is satisfied, the controller 50 determines that the operator "has an intention to cancel the power reduction", and cancels the power reduction control. As a result, it is possible to perform power reduction control when the control lever is not operated, suppress the return to the normal power state when the control lever is moved by mistake, and when returning to the normal power state, You can smoothly transition to the action you want to perform.

1: Hydraulic pump (power source)
2: Pipe line 3: Relief valve 4: Relief pipe line 5: Tank 6: Engine (power source)
7: Rotation speed control device 8: Tandem pipe 9: Parallel pipe 10, 20, 30, 40: Check valves 11, 21, 31, 41: Pipe 12, 22, 32, 42: Directional control valve (power distribution Device)
12r, 12b, 22r, 22b, 32r, 32b, 42r, 42l: pilot lines 13, 23, 33: cylinders (actuators)
13B, 23B, 33B: Bottom pipelines 13R, 23R, 33R: Rod pipelines 13T, 23T, 33T, 43T: Tank pipelines 13C, 23C, 33C, 43C: Center bypass pipeline 14: Operation lever (first operation lever )
15r, 15b, 25r, 25b, 35r, 35b, 45r, 45l: Pilot valves 16r, 16b, 26r, 26b, 36r, 36b, 46r, 46l: Pipe lines 17r, 17b, 27r, 27b, 37r, 37b, 47l, 47r: pressure sensor (operation state detector)
18, 28, 38, 48: pipelines 19, 29, 39, 49: pipeline 34: operation lever (second operation lever)
43: Hydraulic motor 43L: Left rotation pipeline 43R: Right rotation pipeline 50: Controller 51: Pilot pump 52: Pilot pipeline 53: Relief valve 60A: Electric motor (direct current) (power source)
60B: Electric motor (AC) (power source)
61: Inverter 62: Battery (power supply device; power source)
63: Battery output control panel 72, 73, 74, 75: Angle sensor (operation state detection device)
76: Switch 81: Positive wire 82: Negative wire 83, 84, 85, 86: Inverter (power distribution device)
87, 88, 89, 90: Electric motor (AC) (actuator)
91, 92, 93: cylinders (actuators)
94, 95, 96, 97: throttle section 114, 134: operating lever device 314, 334: operating lever device

Claims (6)

a power source;
a plurality of actuators operated by receiving power output from the power source;
a plurality of operating levers for instructing the distribution amount of the power to the plurality of actuators according to the operating state ;
a plurality of operating state detection devices for detecting the operating states of the plurality of operating levers ;
a controller that controls the power source;
the plurality of operating levers have first and second operating levers for operating different actuators among the plurality of actuators;
In the construction machine, the controller performs power reduction control to reduce the power when the first and second control levers continue to be left unoperated.
The controller determines that the operating states of the first and second operating levers detected by the operating state detection device are controlled by the first and second operating levers in a state where the power is reduced by the power reduction control. construction machine, wherein the power reduction control is canceled when a first cancellation condition is satisfied in which the two are simultaneously operated. The construction machine according to claim 1,
The controller is
Even if the first release condition is not satisfied , one of the first and second operating levers is operated while the power is reduced, and the operating state of the one operating lever is maintained in a predetermined state. A construction machine characterized in that the power reduction control is canceled when a second cancellation condition that continues for a period of time is satisfied . The construction machine according to claim 1,
a lower traveling body; an upper revolving body mounted on the lower traveling body so as to be able to turn;
The plurality of actuators include a swing motor for swinging the upper swing structure with respect to the lower traveling structure, and first, second and third front actuators for driving the front working machine,
The first operating lever is an operating lever for operating the first and second front actuators, the second operating lever is an operating lever for operating the turning motor and the third front actuator,
The plurality of operation state detection devices include: a first operation state detection device for detecting an operation state of the first operation lever when the first operation lever operates the first front actuator; a second operating state detection device for detecting an operating state of the first operating lever when operating the second front actuator; and the second operating lever when the second operating lever operates the third front actuator. and a fourth operating state detecting device for detecting the operating state of the second operating lever when the second operating lever operates the turning motor,
Based on the detection results of the first, second, third and fourth operation state detection devices, the controller determines that when the first release condition that the first and second operation levers are simultaneously operated is satisfied, , the construction machine, wherein the power reduction control is canceled when the second operating lever does not operate the swing motor. The construction machine according to claim 1,
the power source includes an engine and a hydraulic pump;
The power source generates the power by driving the hydraulic pump with the engine,
The construction machine, wherein the controller performs the power reduction control by reducing the rotation speed of the engine. The construction machine according to claim 1,
the power source includes a power supply, an electric motor and a hydraulic pump;
The power source drives the electric motor by power supply from the power supply device, and drives the hydraulic pump by the electric motor to generate the power,
The construction machine, wherein the controller performs the power reduction control by reducing power supply to the electric motor to reduce the rotation speed of the electric motor. The construction machine according to claim 1,
the power source includes a power supply;
The actuator is an electric actuator including an electric motor,
The power source drives the electric actuator by power supply from the power supply device,
The construction machine according to claim 1, wherein the controller reduces the power supplied from the power supply device to the electric motor to reduce the rotation speed of the electric motor, thereby reducing the power.

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