The present invention relates to a construction machine such as a hydraulic excavator, and particularly to a construction machine that performs power reduction control of reducing power output by a power source during non-operation of control levers.
Patent Document 1, for example, describes a technology of performing, in a construction machine, power reduction control referred to as auto idle control, which reduces power output by an engine as a power source by reducing the rotation speed of the engine during non-operation of control levers in order to reduce an amount of fuel consumed by the engine and thereby save energy consumption.
The construction machine that performs the power reduction control (auto idle control) of reducing the power output by the engine as a power source during non-operation of the control levers as described in Patent Document 1 is generally allowed to return to a normal power state by canceling the power reduction control when a control lever is operated. However, in the case where the power reduction control is performed in such a manner, when a hand erroneously hits a control lever, for example, a return to the normal power state is made by canceling the control although there is no intention of canceling the power reduction control. That is, although there should be no need to return the engine from a state in which the power is reduced to the normal state, the power reduction control of the engine is canceled. Thus, an effect of saving the energy consumption of the engine is reduced.
The present invention has been made in view of the above-described problems. It is an object of the present invention to provide a construction machine that can perform power reduction control during non-operation of control levers, and suppress power consumption of a power source and thus reduce energy consumption of the power source when a control lever is moved by an erroneous operation.
In order to solve such problems, according to the present invention, there is provided a construction machine including: a power source; a plurality of actuators that operate by receiving power from the power source; a plurality of control levers that instruct amounts of the power to be distributed to the plurality of actuators; a plurality of operation state sensors that detect operation states of the plurality of control levers; and a controller that controls the power output by the power source, the controller being configured to perform power reduction control of the power source on a basis of the operation states of the plurality of control levers detected by the plurality of operation state sensors when a non-operation time of the plurality of control levers exceeds a set time after a transition is made from a state in which at least one of the plurality of control levers is operated to a non-operation state in which none of the plurality of control levers is operated, and to cancel the power reduction control when at least one of the plurality of control levers is operated in a state in which the power reduction control is performed. Further, in the construction machine, the controller is configured to set the set time as a first set time when an operation time until the at least one control lever makes a transition to the non-operation state is longer than a monitoring time set in advance, and set the set time as a second set time shorter than the first set time when the operation time until the at least one control lever makes a transition to the non-operation state is shorter than the monitoring time set in advance.
In this way, the controller is configured to set the set time as the second set time shorter than the first set time when the operation time until the at least one control lever makes a transition to the non-operation state is shorter than the monitoring time set in advance. Consequently, when a control lever is moved by an erroneous operation, the power reduction control is temporarily canceled to return to a normal power state, but a return is thereafter made to a power reduction state in a short time. It is therefore possible to suppress power consumption of the power source and thus reduce energy consumption of the power source when a control lever is moved by an erroneous operation.
According to the present invention, it is possible to perform power reduction control during non-operation of the control levers, and suppress power consumption of the power source when a control lever is moved by an erroneous operation, and thus reduce energy consumption of the power source.
Embodiments of the present invention will hereinafter be described according to the drawings.
A first embodiment of the present invention will be described with reference to
˜Configuration˜
Description will first be made of a hydraulic excavator as a typical example of a construction machine in the first embodiment of the present invention.
The hydraulic excavator includes a lower track structure 101, an upper swing structure 102 swingably mounted on the lower track structure, and a swing type front work implement 104 attached to a front portion of the upper swing structure so as to be rotatable in an upward-downward direction. The front work implement 104 includes a boom 111, an arm 112, and a bucket 113. The upper swing structure 102 and the lower track structure 101 are rotatably connected to each other by a swing wheel 215. The upper swing structure 102 is swingable with respect to the lower track structure 101 by rotation of a swing motor 43. A swing post 103 is attached to a front portion of the upper swing structure 102. The front work implement 104 is attached to the swing post 103 so as to be vertically movable. The swing post 103 is rotatable with respect to the upper swing structure 102 in a horizontal direction by expansion and contraction of a swing cylinder (not shown). The boom 111, the arm 112, and the bucket 113 of the front work implement 104 are rotatable in the upward-downward direction by expansion and contraction of a boom cylinder 13, an arm cylinder 23, and a bucket cylinder 33 as a first front implement actuator, a second front implement actuator, and a third front implement actuator. Attached to a central frame of the lower track structure 101 are a right and a left track device 105a and 105b and a blade 106 that moves up and down according to expansion and contraction of a blade cylinder 3h. The right and left track devices 105a and 105b include driving wheels 210a and 210b, idlers 211a and 211b, and crawlers 212a and 212b, respectively. The right and left track devices 105a and 105b travel by transmitting rotation of a right and a left travelling motor 3f and 3g to the driving wheels 210a and 210b, and thereby driving the crawlers 212a and 212b.
A cabin 110 in which a cab 108 is formed is installed on the upper swing structure 102. The cab 108 is provided with a cab seat 122 and a right and a left control lever device 114 and 134 that instruct driving of the boom cylinder 13, the arm cylinder 23, the bucket cylinder 33, and the swing motor 43. In addition, similar control lever devices are provided also for the travelling motors 3f and 3g, the blade cylinder 3h, and the swing cylinder not shown. These control lever devices are also provided in the cab 108.
Description will next be made of a driving system included in the construction machine (hydraulic excavator) according to the present embodiment.
In
A directional control valve 12 is connected downstream of the line 8 and the line 11. The directional control valve 12 is also connected with a bottom line 13B connected to a bottom side chamber of the boom cylinder 13, a rod line 13R connected to a rod side chamber of the boom cylinder 13, a tank line 13T connected to the tank 5, and a center bypass line 13C.
The directional control valve 12 is driven by the pressure of a pilot line 12b and the pressure of a pilot line 12r. When the pressures of both pilot lines are low, the directional control valve 12 is at a neutral position so that the line 8 is connected to the center bypass line 13C and the other lines are interrupted. When the pressure of the pilot line 12b is high, the directional control valve 12 is switched upward in the figure so that 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 and the center bypass line 13C are interrupted. When the pressure of the pilot line 12r is high, the directional control valve 12 is switched downward in the figure so that 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 and the center bypass line 13C are interrupted.
A directional control valve 22 is connected downstream of the line 13C and the line 21. The directional control valve 22 is also connected with a bottom line 23B connected to a bottom side chamber of the arm cylinder 23, a rod line 23R connected to a rod side chamber of the arm cylinder 23, a tank line 23T connected to the tank 5, and a center bypass line 23C.
The directional control valve 22 is driven by the pressure of a pilot line 22b and the pressure of a pilot line 22r. When the pressures of both pilot lines are low, the directional control valve 22 is at a neutral position so that the center bypass line 13C is connected to the center bypass line 23C and the other lines are interrupted. When the pressure of the pilot line 22b is high, the directional control valve 22 is switched upward in the figure so that 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 and the center bypass line 23C are interrupted. When the pressure of the pilot line 22r is high, the directional control valve 22 is switched downward in the figure so that 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 and the center bypass line 23C are interrupted.
A directional control valve 32 is connected downstream of the line 23C and the line 31. The directional control valve 32 is also connected with a bottom line 33B connected to a bottom side chamber of the bucket cylinder 33, a rod line 33R connected to a rod side chamber of the bucket cylinder 33, a tank line 33T connected to the tank 5, and a center bypass line 33C.
The directional control valve 32 is driven by the pressure of a pilot line 32b and the pressure of a pilot line 32r. When the pressures of both of the pilot lines are low, the directional control valve 32 is at a neutral position so that the center bypass line 23C is connected to the center bypass line 33C and the other lines are interrupted. When the pressure of the pilot line 32b is high, the directional control valve 32 is switched upward in the figure so that 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 and the center bypass line 33C are interrupted. When the pressure of the pilot line 32r is high, the directional control valve 32 is switched downward in the figure so that 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 and the center bypass line 33C are interrupted.
A directional control valve 42 is connected downstream of the line 33C and the line 41. The directional control valve 42 is also connected with a left rotation line 43L connected to a left rotation side chamber of the swing motor 43, a right rotation line 43R connected to a right rotation side chamber of the swing motor 43, a tank line 43T connected to the tank 5, and a center bypass line 43C. The center bypass line 43C is connected to the tank 5.
The directional control valve 42 is driven by the pressure of a pilot line 42l and the pressure of a pilot line 42r. When the pressures of both of the pilot lines are low, the directional control valve 42 is at a neutral position so that the center bypass line 33C is connected to the center bypass line 43C and the other lines are interrupted. When the pressure of the pilot line 42l is high, the directional control valve 42 is switched upward in the figure so that 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 33C and the center bypass line 43C are interrupted. When the pressure of the pilot line 42r is high, the directional control valve 42 is switched downward in the figure so that 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 33C and the center bypass line 43C are interrupted.
The pilot pump 51 is connected to a pilot line 52. The downstream of the pilot line 52 will be described later with reference to
Incidentally, though not shown, the hydraulic drive system has similar directional control valves provided also for the travelling motors 3f and 3g and the blade cylinder 3h shown in
Here, the engine 6 and the hydraulic pump 1 constitute a power source, and the boom cylinder 13, the arm cylinder 23, the bucket cylinder 33, the swing motor 43, the travelling motors 3f and 3g, the blade cylinder 3h, and the swing cylinder not shown constitute a plurality of actuators that are actuated by receiving power from the power source. A plurality of control levers of the control lever devices 114 and 134 shown in
Configurations of control lever devices will next be described with reference to
As described with reference to
Incidentally, the forward direction, the rearward direction, the right direction, and the left direction in the present specification refer to a front direction, a rear direction, a right direction, and a left direction of the upper swing structure 102 as a machine body.
Thus, the control levers 14 and 34 of the control lever devices 114 and 134 can be operated in the plurality of directions from the neutral position, and operate different actuators among the plurality of actuators (the boom cylinder 13, the arm cylinder 23, the bucket cylinder 33, and the swing motor 43).
In
Lines 19, 29, 39, and 49 and a relief valve 53 are connected in parallel with each other downstream of the pilot line 52. The tank 5 is connected downstream of the relief valve 53. The lines 19, 29, 39, and 49 are provided with restricting sections 94, 95, 96, and 97, respectively.
The pilot valve 15b of the control lever device 114 is connected to the line 19, and is connected to a line 18 and a line 16b. The line 16b is connected to the pilot line 12b (see
When the lever 14 is at the neutral position, the pilot valve 15b connects the line 18 and the line 16b to each other, and interrupts the line 19. When the lever 14 is operated in the forward direction 14b, the pilot valve 15b connects the line 19 and the line 16b to each other, and interrupts the line 18. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 14 is generated in the line 16b.
The pressure sensor 17b measures the pressure of the line 16b, and transmits a signal to a controller 50 electrically connected to the pressure sensor 17b.
The pilot valve 15r of the control lever device 114 is connected to the line 19, and is connected to the line 18 and a line 16r. The line 16r is connected to the pilot line 12r (see
When the lever 14 is at the neutral position, the pilot valve 15r connects the line 18 and the line 16r to each other, and interrupts the line 19. When the lever 14 is operated in the rearward direction 14r, the pilot valve 15r connects the line 19 and the line 16r to each other, and interrupts the line 18. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 14 is generated in the line 16r.
The pressure sensor 17r measures the pressure of the line 16r, and transmits a signal to the controller 50 electrically connected to the pressure sensor 17r.
The pilot valve 25b of the control lever device 114 is connected to the line 29, and is connected to a line 28 and a line 26b. The line 26b is connected to the pilot line 32b (see
When the lever 14 is at the neutral position, the pilot valve 25b connects the line 28 and the line 26b to each other, and interrupts the line 29. When the lever 14 is operated in the left direction 24b, the pilot valve 25b connects the line 29 and the line 26b to each other, and interrupts the line 28. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 14 is generated in the line 26b.
The pressure sensor 27b measures the pressure of the line 26b, and transmits a signal to the controller 50 electrically connected to the pressure sensor 27b.
The pilot valve 25r of the control lever device 114 is connected to the line 29, and is connected to the line 28 and a line 26r. The line 26r is connected to the pilot line 32r (see
When the lever 14 is at the neutral position, the pilot valve 25r connects the line 28 and the line 26r to each other, and interrupts the line 29. When the lever 14 is operated in the right direction 24r, the pilot valve 25r connects the line 29 and the line 26r to each other, and interrupts the line 28. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 14 is generated in the line 26r.
The pressure sensor 27r measures the pressure of the line 26r, and transmits a signal to the controller 50 electrically connected to the pressure sensor 27r.
The pilot valve 35b of the control lever device 134 is connected to the line 39, and is connected to a line 38 and a line 36b. The line 36b is connected to the pilot line 22b (see
When the lever 34 is at the neutral position, the pilot valve 35b connects the line 38 and the line 36b to each other, and interrupts the line 39. When the lever 34 is operated in the right direction 34b, the pilot valve 35b connects the line 39 and the line 36b to each other, and interrupts the line 38. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 34 is generated in the line 36b.
The pressure sensor 37b measures the pressure of the line 36b, and transmits a signal to the controller 50 electrically connected to the pressure sensor 37b.
The pilot valve 35r of the control lever device 134 is connected to the line 39, and is connected to the line 38 and a line 36r. The line 36r is connected to the pilot line 22r (see
When the lever 34 is at the neutral position, the pilot valve 35r connects the line 38 and the line 36r to each other, and interrupts the line 39. When the lever 34 is operated in the left direction 34r, the pilot valve 35r connects the line 39 and the line 36r to each other, and interrupts the line 38. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 34 is generated in the line 36r.
The pressure sensor 37r measures the pressure of the line 36r, and transmits a signal to the controller 50 electrically connected to the pressure sensor 37r.
The pilot valve 45l of the control lever device 134 is connected to the line 49, and is connected to a line 48 and a line 46l. The line 46l is connected to the pilot line 42l (see
When the lever 34 is at the neutral position, the pilot valve 45l connects the line 48 and the line 46l to each other, and interrupts the line 49. When the lever 34 is operated in the forward direction 44l, the pilot valve 45l connects the line 49 and the line 46l to each other, and interrupts the line 48. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 34 is generated in the line 46l.
The pressure sensor 47l measures the pressure of the line 46l, and transmits a signal to the controller 50 electrically connected to the pressure sensor 47l.
The pilot valve 45r of the control lever device 134 is connected to the line 49, and is connected to the line 48 and a line 46r. The line 46r is connected to the pilot line 42r (see
When the lever 34 is at the neutral position, the pilot valve 45r connects the line 48 and the line 46r to each other, and interrupts the line 49. When the lever 34 is operated in the rearward direction 44r, the pilot valve 45r connects the line 49 and the line 46r to each other, and interrupts the line 48. At this time, a pressure (operation pressure) corresponding to an operation amount of the lever 34 is generated in the line 46r.
The pressure sensor 47r measures the pressure of the line 46r, and transmits a signal to the controller 50 electrically connected to the pressure sensor 47r.
The pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r constitute a plurality of operation state sensors that detect operation states of the control lever devices 114 and 134. In addition, the pressure sensors 17b and 17r constitute a first operation state sensor that detects the operation state in a forward-rearward direction of the control lever 14. The pressure sensors 27b and 27r constitute a second operation state sensor that detects the operation state in a right-left direction of the control lever 14. The pressure sensors 37b and 37r constitute a third operation state sensor that detects the operation state in the right-left direction of the control lever 34. The pressure sensors 47l and 47r constitute a fourth operation state sensor that detects the operation state in the forward-rearward direction of the control lever 34.
Incidentally, though not shown, the operating system has similar pressure sensors (operation state sensors) provided also for the control lever devices other than the control lever devices 114 and 134, and power reduction control to be described later can be performed on the basis of the operation states of the control levers of these control lever devices.
Returning to
The controller 50 is electrically connected to the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r, the switch 76, and the target rotation speed indicating device 77. The controller 50 receives signals of measured pressures from the pressure sensors 17b to 47r, a signal from the switch 76, and a signal from the target rotation speed indicating device 77, computes a target rotation speed for controlling the engine 6 on the basis of these signals, and transmits a command signal of the target rotation speed to a rotation speed controller 7 of the engine 6, which is electrically connected to the controller 50. The rotation speed controller 7 controls the engine 6 so as to achieve the target rotation speed.
The switch 76 is a switch that selects whether to set a 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 driving power of the engine 6 is not reduced even if all of the control levers are in a non-operation state.
Functions of the controller 50 in the first embodiment will next be described.
A basic concept of control performed by the controller 50 will first be described.
The controller 50 performs power reduction control of the engine 6 and the hydraulic pump 1 (power source) on the basis of the operation states of the control levers 14 and 34 (plurality of control levers) detected by the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r (plurality of operation state sensors) when a non-operation time of the control levers 14 and 34 exceeds a set time after a transition is made from a state in which at least one of the control levers 14 and 34 is operated to a non-operation state in which none of the control levers 14 and 34 is operated. The controller 50 cancels the power reduction control when at least one of the control levers 14 and 34 is operated in a state in which the power reduction control is performed.
In addition, as characteristic functions of the controller 50, the controller 50 sets the above-described set time as a first set time Tth1 when an operation time until at least one control lever makes a transition to the non-operation state is longer than a monitoring time Tth0 set in advance, and sets the above-described set time as a second set time Tth2 shorter than the first set time Tth1 when the time until the at least one control lever makes a transition to the non-operation state is shorter than the monitoring time Tth0 set in advance.
In addition, the controller 50 generates non-operation flags F14(t) and F34(t) (non-operation state information) indicating that the control levers 14 and 34 are in a non-operation state and a power reduction flag F50(t) (power reduction control state information) indicating that the power reduction control is performed on the basis of the operation states of the control levers 14 and 34 (plurality of control levers) detected by the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r (plurality of operation state sensors), calculates a power non-reduction time during which the power reduction control is not performed on the basis of the non-operation flags F14(t) and F34(t) and the power reduction flag F50(t), and uses the power non-reduction time as the operation time of the control levers 14 and 34.
Further, the controller 50 determines that the operation of the at least one control lever is an erroneous operation when the transition is made from the state in which the at least one control lever is operated to the non-operation state in which none of the control levers 14 and 34 is operated and when the at least one control lever becomes non-operated during the monitoring time Tth0.
Details of the above-described basic concept of the controller 50 will be described in the following. Incidentally, in the following, description of the power reduction control based on the operation states of the control levers other than the control levers 14 and 34 will be omitted, and the power reduction control will be described with the operation states of the control levers 14 and 34 as a representative.
In
The sensor signal converting section 50a receives signals sent from the pressure sensors 17b to 47r and the switch 76, and converts the signals into pressure information and switch flag information. The sensor signal converting section 50a transmits the converted pressure information and the converted switch flag information to the power computing section 50c. The pressure information converted by the sensor signal converting section 50a is pressures generated in the lines 16b to 46r by driving the pilot valves 15b to 45r, and is shown as sensor values P17b(t), P17r(t), P27b(t), P27r(t), P37b(t), P37r(t), P47l(t), and P47r(t) in
The constant and table storage section 50b stores constants and tables necessary for calculation. The constant and table storage section 50b transmits these pieces of information to the power computing section 50c. The constants stored in the constant and table storage section 50b include the monitoring time Tth0, the first set time Tth1, and the second set time Tth2 described above.
The power computing section 50c receives the pressure information and the switch flag information transmitted from the sensor signal converting section 50a, target rotation speed information transmitted from the target rotation speed indicating device 77, and constant information (the monitoring time Tth0, the first set time Tth1, and the second set time Tth2) and table information transmitted from the constant and table storage section 50b, and computes the target rotation speed of the engine 6. Then, the power computing section 50c outputs the target rotation speed for control to the rotation speed controller 7.
Functions of the power computing section 50c in the first embodiment will next be described.
In
The lever 14 operation state determining section 50c-1 determines whether the lever 14 is operated from the sensor values P17b(t), P17r(t), P27b(t), and P27r(t), and outputs the lever 14 non-operation flag F14(t). The lever 14 operation state determining section 50c-1 sets the lever 14 non-operation flag F14(t) true when determining that the lever 14 is not operated. The lever 14 operation state determining section 50c-1 sets the lever 14 non-operation flag F14(t) false when determining that the lever 14 is operated. This lever 14 non-operation flag F14(t) (which may hereinafter be referred to simply as flag information F14(t)) is transmitted to the lever 14 non-operation time measuring section 50c-3 and the power non-reduction time measuring section 50c-7.
The lever 34 operation state determining section 50c-2 determines whether the lever 34 is operated from the sensor values P37b(t), P37r(t), P47l(t), and P47r(t), and outputs the lever 34 non-operation flag F34(t). The lever 34 non-operation state determining section 50c-2 sets the lever 34 non-operation flag F34(t) true when determining that the lever 34 is not operated. The lever 34 non-operation state determining section 50c-2 sets the lever 34 non-operation flag F34(t) false when determining that the lever 34 is operated. This lever 34 non-operation flag F34(t) (which may hereinafter be referred to simply as flag information F34(t)) is transmitted to the lever 34 non-operation time measuring section 50c-4 and the power non-reduction time measuring section 50c-7.
The lever 14 non-operation time measuring section 50c-3 measures a lever 14 non-operation time Tu14(t) on the basis of the flag information F14(t), and transmits the lever 14 non-operation time Tu14(t) (which may hereinafter be referred to simply as time information Tu14(t)) to the power reduction determining section 50c-5.
The lever 34 non-operation time measuring section 50c-4 measures a lever 34 non-operation time Tu34(t) on the basis of the flag information F34(t), and transmits the lever 34 non-operation time Tu34(t) (which may hereinafter be referred to simply as time information Tu34(t)) to the power reduction determining section 50c-5.
The power non-reduction time measuring section 50c-7 measures a power non-reduction time TF50(t) on the basis of the flag information F14(t) and the flag information F34(t) and a power reduction flag F50(t−Δt) preceding by one step, which is generated by the delay element 50c-6, and transmits the power non-reduction time TF50(t) (which may hereinafter be referred to simply as time information TF50(t)) to the power reduction determining section 50c-5.
The power reduction determining section 50c-5 determines whether to reduce the target rotation speed for control on the basis of the time information Tu14(t) and Tu34(t) and the time information TF50(t), the switch flag Fsw(t), and the target rotation speed transmitted from the target rotation speed indicating device 77, and outputs the target rotation speed for control and the power reduction flag F50(t) on the basis of a result of the determination. In addition, the power reduction determining section 50c-5 sets the power reduction flag F50(t) true when determining that the target rotation speed is to be reduced, and the power reduction determining section 50c-5 sets the power reduction flag F50(t) false when determining that the target rotation speed is not to be reduced.
(Lever 14 Operation State Determining Section 50c-1)
Functions of the lever 14 operation state determining section 50c-1 in the first embodiment will next be described.
The computation of the lever 14 operation state determining section 50c-1 is started in step S101.
In step S102, the lever 14 operation state determining section 50c-1 determines whether the sensor value P17b(t) is equal to or smaller than a threshold value Pth. When the sensor value P17b(t) is equal to or less than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines Yes, and proceeds to the processing of step S103. When the sensor value P17b(t) is larger than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines No, and proceeds to the processing of step S107.
In step S103, the lever 14 operation state determining section 50c-1 determines whether the sensor value P17r(t) is equal to or smaller than the threshold value Pth. When the sensor value P17r(t) is equal to or smaller than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines Yes, and proceeds to the processing of step S104. When the sensor value P17r(t) is larger than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines No, and proceeds to the processing of step S107.
In step S104, the lever 14 operation state determining section 50c-1 determines whether the sensor value P27b(t) is equal to or smaller than the threshold value Pth. When the sensor value P27b(t) is equal to or smaller than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines Yes, and proceeds to the processing of step S105. When the sensor value P27b(t) is larger than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines No, and proceeds to the processing of step S107.
In step S105, the lever 14 operation state determining section 50c-1 determines whether the sensor value P27r(t) is equal to or smaller than the threshold value Pth. When the sensor value P27r(t) is equal to or smaller than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines Yes, and proceeds to the processing of step S106. When the sensor value P27r(t) is larger than the threshold value Pth, the lever 14 operation state determining section 50c-1 determines No, and proceeds to the processing of step S107.
In step S106, the lever 14 operation state determining section 50c-1 determines that the lever 14 is not operated, and sets the lever 14 non-operation flag F14(t) true. Then, the lever 14 operation state determining section 50c-1 transmits the flag information to the lever 14 non-operation time measuring section 50c-3 and the power reduction determining section 50c-5.
In step S107, the lever 14 operation state determining section 50c-1 determines that the lever 14 is operated, and sets the lever 14 non-operation flag F14(t) false. Then, the lever 14 operation state determining section 50c-1 transmits the flag information to the lever 14 non-operation time measuring section 50c-3 and the power reduction determining section 50c-5.
(Lever 34 Operation State Determining Section 50c-2)
Functions of the lever 34 operation state determining section 50c-2 in the first embodiment will next be described.
The computation of the lever 34 operation state determining section 50c-2 is started in step S201.
In step S202, the lever 34 operation state determining section 50c-2 determines whether the sensor value P37b(t) is equal to or smaller than the threshold value Pth. When the sensor value P37b(t) is equal to or smaller than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines Yes, and proceeds to the processing of step S203. When the sensor value P37b(t) is larger than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines No, and proceeds to the processing of step S207.
In step S203, the lever 34 operation state determining section 50c-2 determines whether the sensor value P37r(t) is equal to or smaller than the threshold value Pth. When the sensor value P37r(t) is equal to or smaller than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines Yes, and proceeds to the processing of step S204. When the sensor value P37r(t) is larger than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines No, and proceeds to the processing of step S207.
In step S204, the lever 34 operation state determining section 50c-2 determines whether the sensor value P47l(t) is equal to or smaller than the threshold value Pth. When the sensor value P47l(t) is equal to or smaller than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines Yes, and proceeds to the processing of step S205. When the sensor value P47l(t) is larger than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines No, and proceeds to the processing of step S207.
In step S205, the lever 34 operation state determining section 50c-2 determines whether the sensor value P47r(t) is equal to or smaller than the threshold value Pth. When the sensor value P47r(t) is equal to or smaller than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines Yes, and proceeds to the processing of step S206. When the sensor value P47r(t) is larger than the threshold value Pth, the lever 34 operation state determining section 50c-2 determines No, and proceeds to the processing of step S207.
In step S206, the lever 34 operation state determining section 50c-2 determines that the lever 34 is not operated, and sets the lever 34 non-operation flag F34(t) true. Then, the lever 34 operation state determining section 50c-2 transmits the flag information to the lever 34 non-operation time measuring section 50c-4 and the power reduction determining section 50c-5.
In step S207, the lever 34 operation state determining section 50c-2 determines that the lever 14 is operated, and sets the lever 34 non-operation flag F34(t) false. Then, the lever 34 operation state determining section 50c-2 transmits the flag information to the lever 34 non-operation time measuring section 50c-4 and the power reduction determining section 50c-5.
A definition of the threshold value Pth for the above-described sensor values will be described with reference to
In
(Lever 14 Non-Operation Time Measuring Section 50c-3)
Functions of the lever 14 non-operation time measuring section 50c-3 in the first embodiment will next be described.
The computation of the lever 14 non-operation time measuring section 50c-3 is started in step S301.
In step S302, the lever 14 non-operation time measuring section 50c-3 determines whether the lever 14 non-operation flag F14(t) is true. When the lever 14 non-operation flag F14(t) is true, the lever 14 non-operation time measuring section 50c-3 determines Yes, and proceeds to the processing of step S303. When the lever 14 non-operation flag F14(t) is false, the lever 14 non-operation time measuring section 50c-3 determines No, and proceeds to the processing of step S304.
In step S303, since the lever 14 is not operated, the lever 14 non-operation time measuring section 50c-3 sets, as a new lever 14 non-operation time Tu14(t), a value obtained by adding a sampling time Δt to a retained lever 14 non-operation time Tu14(t−Δt) preceding by one step. Then, the lever 14 non-operation time measuring section 50c-3 transmits the information to the power reduction determining section 50c-5.
In step S304, since the lever 14 is operated, the lever 14 non-operation time measuring section 50c-3 sets the lever 14 non-operation time Tu14(t) to zero. Then, the lever 14 non-operation time measuring section 50c-3 transmits the information to the power reduction determining section 50c-5.
(Lever 34 Non-Operation Time Measuring Section 50c-4)
Functions of the lever 34 non-operation time measuring section 50c-4 in the first embodiment will next be described.
The computation of the lever 34 non-operation time measuring section 50c-4 is started in step S401.
In step S402, the lever 34 non-operation time measuring section 50c-4 determines whether the lever 34 non-operation flag F34(t) is true. When the lever 34 non-operation flag F34(t) is true, the lever 34 non-operation time measuring section 50c-4 determines Yes, and proceeds to the processing of step S403. When the lever 34 non-operation flag F34(t) is false, the lever 34 non-operation time measuring section 50c-4 determines No, and proceeds to the processing of step S404.
In step S403, since the lever 34 is not operated, the lever 34 non-operation time measuring section 50c-4 sets, as a new lever 34 non-operation time Tu34(t), a value obtained by adding a sampling time Δt to a retained lever 34 non-operation time Tu34(t−Δt) preceding by one step. Then, the lever 34 non-operation time measuring section 50c-4 transmits the information to the power reduction determining section 50c-5.
In step S404, since the lever 34 is operated, the lever 34 non-operation time measuring section 50c-4 sets the lever 34 non-operation time Tu34(t) to zero. Then, the lever 34 non-operation time measuring section 50c-4 transmits the information to the power reduction determining section 50c-5.
(Power Non-Reduction Time Measuring Section 50c-7)
Functions of the power non-reduction time measuring section 50c-7 in the first embodiment will next be described.
The computation of the power non-reduction time measuring section 50c-7 is started in step S1401.
In step S1402, the power non-reduction time measuring section 50c-7 determines whether the power reduction flag F50(t−Δt) preceding by one step is false. When the power reduction flag F50(t−Δt) is false, the power non-reduction time measuring section 50c-7 determines Yes, and proceeds to the processing of step S1403. When the power reduction flag F50(t−Δt) is true, the power non-reduction time measuring section 50c-7 determines No, and proceeds to the processing of step S1407.
In step S1403, the power non-reduction time measuring section 50c-7 determines whether the lever 14 non-operation flag F14(t) is true. When the lever 14 non-operation flag F14(t) is true, the power non-reduction time measuring section 50c-7 determines Yes, and proceeds to the processing of step S1404. When the lever 14 non-operation flag F14(t) is false, the power non-reduction time measuring section 50c-7 determines No, and proceeds to the processing of step S1406.
In step S1404, the power non-reduction time measuring section 50c-7 determines whether the lever 34 non-operation flag F34(t) is true. When the lever 34 non-operation flag F34(t) is true, the power non-reduction time measuring section 50c-7 determines Yes, and proceeds to the processing of step S1405. When the lever 34 non-operation flag F34(t) is false, the power non-reduction time measuring section 50c-7 determines No, and proceeds to the processing of step S1406.
In step S1406, since the power reduction flag F50(t−Δt) is false and thus does not indicate a power reduction state, and at least one of the lever 14 non-operation flag F14(t) and the lever 34 non-operation flag F34(t) is not true (at least one of the levers 14 and 34 is operated), the power non-reduction time measuring section 50c-7 sets, as a new power non-reduction time TF50(t), a value obtained by adding a sampling time Δt to the power non-reduction time TF50(t−Δt) preceding by one step. Then, the power non-reduction time measuring section 50c-7 transmits the information to the power reduction determining section 50c-5.
In step S1405, when the power reduction flag F50(t−Δt) is false and thus does not indicate a power reduction state, and both the lever 14 non-operation flag F14(t) and the lever 34 non-operation flag F34(t) become true (both of the levers 14 and 34 become non-operated), the power non-reduction time measuring section 50c-7 sets the power non-reduction time TF50(t−Δt) preceding by one step as a new power non-reduction time TF50(t), and retains the power non-reduction time TF50(t−Δt) preceding by one step as the power non-reduction time TF50(t). Then, the power non-reduction time measuring section 50c-7 transmits the information to the power reduction determining section 50c-5.
Here, the power non-reduction time TF50(t) set in step S1405 (power non-reduction time TF50(t−Δt) preceding by one step) means an operation time from a time that at least one of the levers 14 and 34 is operated (power reduction control is canceled) to a time that both of the levers 14 and 34 become non-operated (power reduction control is performed again).
In step S1407, since the power reduction flag F50(t−Δt) is not false and thus indicates a power reduction state, the power non-reduction time measuring section 50c-7 sets the power non-reduction time TF50(t) to zero. Then, the power non-reduction time measuring section 50c-7 transmits the information to the power reduction determining section 50c-5.
(Power Reduction Determining Section 50c-5)
Functions of the power reduction determining section 50c-5 in the first embodiment will next be described.
The computation of the power reduction determining section 50c-5 is started in step S501.
In step S502, the power reduction determining section 50c-5 determines whether the switch flag Fsw(t) is true. When the switch flag Fsw(t) is true, the power reduction determining section 50c-5 determines Yes, and proceeds to the processing of step S503. When the switch flag Fsw(t) is false, the power reduction determining section 50c-5 determines No, and proceeds to the processing of step S509.
In step S503, the power reduction determining section 50c-5 determines whether the power non-reduction time TF50(t) is equal to or more than a preset monitoring time Tth0 for an erroneous operation of the lever 14 or 34. When the power non-reduction time TF50(t) is equal to or more than the monitoring time Tth0, the power reduction determining section 50c-5 determines Yes, and proceeds to the processing of step S504. When the power non-reduction time TF50(t) is smaller than the monitoring time Tth0, the power reduction determining section 50c-5 determines No, and proceeds to the processing of step S505. The power non-reduction time TF50(t) corresponds to an operation time from a time of a start of operation of the control lever 14 or 34, as described above. Incidentally, instead of using the power non-reduction time TF50(t) as the operation time, the operation time of the levers 14 and 37 may be calculated by directly using the sensor values P17b(t), P17r(t), P27b(t), P27r(t), P37b(t), P37r(t), P47l(t), and P47r(t) (operation pressures) of the pressure sensors 17b to 47r, and the operation time may be used.
In step S504, the power reduction determining section 50c-5 determines whether a smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is equal to or more than the first set time Tth1 as a normal power reduction control time. When the smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is equal to or more than the first set time Tth1, the power reduction determining section 50c-5 determines Yes, and proceeds to the processing of step S506. When the smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is smaller than the first set time Tth1, the power reduction determining section 50c-5 determines No, and proceeds to the processing of step S507.
In step S505, the power reduction determining section 50c-5 determines whether the smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is equal to or more than the second set time Tth2. When the smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is equal to or more than the second set time Tth2, the power reduction determining section 50c-5 determines Yes, and proceeds to the processing of step S508. When the smaller value of the lever 14 non-operation time Tu14(t) and the lever 34 non-operation time Tu34(t) is smaller than the second set time Tth2, the power reduction determining section 50c-5 determines No, and proceeds to the processing of step S509.
Incidentally, the second set time Tth2 is set shorter than the first set time Tth1 as a normal power reduction control time. The first set time Tth1 is for example 3 to 5 seconds. The second set time Tth2 is for example 0.5 to 2 seconds.
In addition, the monitoring time Tth0 is set at a maximum value of a time for which an erroneous operation of the lever 14 or 34 can be considered to be performed. It is thereby possible to monitor the operation time (power non-reduction time TF50(t)) of the lever 14 or 34 during the monitoring time Tth0, and determine that an erroneous operation is performed when the operation time is shorter than the monitoring time Tth0.
The maximum value of the operation time for which an erroneous operation of the lever 14 or 34 can be considered to be performed can be determined by collecting data on the operation time in advance. In a case where the first set time Tth1 is for example 3 to 5 seconds, and the second set time Tth2 is for example 0.5 to 2 seconds, the monitoring time Tth0 is for example 1 to 2.5 seconds.
The power reduction determining section 50c-5 performs same processing in step S506 and step S508. Specifically, in step S506 and step S508, the power reduction determining section 50c-5 sets the power reduction flag true, and at the same time, the power reduction determining section 50c-5 sets the target rotation speed for controlling the engine 6 to a target rotation speed for power reduction control, which is lower than a normal target rotation speed indicated by the target rotation speed indicating device 77. Then, the power reduction determining section 50c-5 transmits the target rotation speed to the rotation speed controller 7. The rotation speed controller 7 decreases the rotation speed of the engine 6 by reducing an amount of fuel supplied to the engine 6. The power reduction determining section 50c-5 thus performs power reduction control in step S506 and step S508.
The power reduction determining section 50c-5 performs same processing in step S507 and step S509. Specifically, in step S507 and step S509, the power reduction determining section 50c-5 sets the power reduction flag F50(t) false, and at the same time, the power reduction determining section 50c-5 sets the target rotation speed for controlling the engine 6 to the normal target rotation speed indicated by the target rotation speed indicating device 77. Then, the power reduction determining section 50c-5 transmits the target rotation speed to the rotation speed controller 7. The rotation speed controller 7 increases the rotation speed of the engine 6 by increasing the amount of fuel supplied to the engine 6. The power reduction determining section 50c-5 thus cancels the power reduction control in step S507 and step S509.
˜Operation˜
An example of changes in operation pressures and target rotation speed in the first embodiment will next be described with reference to
At time t0, the lever 14 is operated in the forward direction 14b, and the lever 34 is operated in the right direction 34b. Therefore, both the operation pressure P17b(t) and the operation pressure P37b(t) exceed the threshold value Pth. The other operation pressures not shown in the figure are zero. At this time, the processing of step S507 in
From time t0 to time t1, the operation pressures P17b(t) and P37b(t) are both larger than the threshold value Pth. Also in this case, the processing of step S507 in
At time t1, both of the levers 14 and 34 are returned to neutral, and thus both of the operation pressures P17b(t) and P37b(t) are a value smaller than the threshold value Pth. Therefore, until the first set time Tth1 passes from time t1, the processing of step S507 is performed (S502→S503→S504→S507), and the target rotation speed for controlling the engine 6 is thereby set to the normal value Nh so that normal power control is performed. When the first set time Tth1 thereafter passes from time t1, the processing of step S506 in
At time t2, the operation pressure P37b(t) is larger than the threshold value Pth due to an erroneous operation of the lever 34. At this time, the processing of step S509 in
Thereafter, at time t3, the lever 34 returns to neutral, and the operation pressure P37b(t) is thereby decreased, thus both of the operation pressures P17b(t) and P37b(t) become a value smaller than the threshold value Pth (non-operation state). Therefore, until the second set time Tth2 passes from time t3, the processing of step S509 is performed (S502→S503→S505→S509), and the target rotation speed for controlling the engine 6 thereby continues to be set to the normal value Nh so that the normal power control is performed. When the seconds of the second set time Tth2 thereafter pass from time t3, the processing of step S508 in
Incidentally, a time from time t2 to time t3 is an erroneous operation time of the lever 34. Since the erroneous operation monitoring time Tth0 is set to the maximum value of the time for which an erroneous operation can be considered to be performed, it is possible to reliably monitor the erroneous operation time in step 503, proceed to step S508 in the second set time Tth2 shorter than the first set time Tth1, and perform the power reduction control.
Thereafter, at time t4, the operation pressure P37b(t) becomes larger than the threshold value Pth again due to an erroneous operation of the lever 34. Also in this case, the processing of step S509 in
Thereafter, at time t5, the lever 34 returns to neutral, and the operation pressure P37b(t) is thereby decreased, thus both of the operation pressures P17b(t) and P37b(t) become a value smaller than the threshold value Pth (non-operation state). Therefore, also in this case, until the second set time Tth2 passes from time t5, the processing of step S509 is performed (S502→S503→S505→S509), and the target rotation speed for controlling the engine 6 thereby continues to be set to the normal value Nh so that the normal power control is performed. When the second set time Tth2 thereafter passes from time t5, the processing of step S508 in
Incidentally, an erroneous operation time t4 to t5 in this case is longer than the erroneous operation time t2 to t3. However, the erroneous operation monitoring time Tth0 is set to the maximum value of the time for which an erroneous operation can be considered to be performed. Thus, the determination in step S503 continues to be negative during the erroneous operation. It is therefore possible to reliably monitor an erroneous operation in step 503, proceed to step S508 in the second set time Tth2 shorter than the first set time Tth1 also in this case, and perform the power reduction control.
Thereafter, at time t6, the lever 14 is operated by the operator intending to perform work. At time t7, the lever 34 is returned to neutral.
At time t6, the operation pressure P17b(t) is larger than the threshold value Pth. At this time, the processing of step S509 in
An operation time from time t6 to time t7 is an operation time in which work is intended, and is longer than the erroneous operation monitoring time Tth0. Therefore, until the monitoring time Tth0 passes from time t6, the processing of step S509 is performed (S502→S503→S505→S509), and the target rotation speed for controlling the engine 6 thereby continues to be set to the normal value Nh so that the normal power control is performed. When the seconds of the monitoring time Tth0 pass from time t6, the processing of step S507 is performed (S502→S503→S504→S507) until time t7. Also in this case, the target rotation speed for controlling the engine 6 continues to be set to the normal value Nh so that the normal power control is performed.
When the lever 34 is thereafter returned to neutral at time t7, the operation pressure P17b(t) decreases, thus both of the operation pressures P17b(t) and P37b(t) become a value smaller than the threshold value Pth (non-operation state). Therefore, until the first set time Tth1 passes from time t7, the processing of step S507 is performed (S502→S503→S504→S507), and the target rotation speed for controlling the engine 6 thereby continues to be set to the normal value Nh so that the normal power control is performed. When the first set time Tth1 thereafter passes from time t7, the processing of step S506 in
˜Effects˜
As described above, according to the present embodiment, the controller 50 performs the power reduction control that reduces the power output by the engine 6 and the hydraulic pump 1 (power source) when a transition is made from a state in which at least one of the control levers 14 and 34 (plurality of control levers) is operated to a non-operation state in which none of the control levers 14 and 34 is operated and a non-operation time after the transition to the non-operation state exceeds the set time Tth1 or Tth2. When at least one of the control levers 14 and 34 is operated in a state in which the power reduction control is performed, the controller 50 cancels the power reduction control, and restores the power output by the engine 6 and the hydraulic pump 1 to the power before the reduction.
It is thereby possible to perform the power reduction control during non-operation of the control levers, and make a smooth transition to an operation desired to be performed at a time of a return to a normal power state.
In addition, the controller 50 sets the set time as the first set time Tth1 when an operation time until at least one control lever makes a transition to the non-operation state is longer than the monitoring time Tth0 set in advance, and the controller 50 sets the set time as the second set time Tth2 shorter than the first set time Tth1 when the operation time until the at least one control lever makes a transition to the non-operation state is shorter than the monitoring time Tth0 set in advance. Therefore, when the control lever(s) 14 and/or 34 is moved by an erroneous operation, the power reduction control is temporarily canceled, and a return is made to a normal power state. However, a return is thereafter made to a power reduction state in a short time.
It is thereby possible to suppress power consumption of the engine 6 (power source) and thus reduce an amount of fuel consumed by the engine 6 (energy consumption) when the control lever(s) 14 and/or 34 is moved by an erroneous operation.
In addition, the controller 50 generates the non-operation flags F14(t) and F34(t) (non-operation state information) and the power reduction flag F50(t) (power reduction control state information) on the basis of the operation states of the control levers 14 and 34, which are detected by the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r (plurality of operation state sensors), calculates the power non-reduction time TF50(t) on the basis of the non-operation flags F14(t) and F34(t) and the power reduction flag F50, and uses this power non-reduction time TF50(t) as the operation time of the control levers 14 and 34. It is thereby possible to simplify the control computation of the controller 50.
A second embodiment of the present invention will be described with reference to
A configuration of a driving system in the second embodiment will first be described.
In
The battery output power control panel 63 controls the electric power output by the battery 62 on the basis of target battery output power information transmitted from the controller 50A. The target rotation speed indicating device 77 is replaced with a target electric power indicating device 77A.
Here, the battery 62 constitutes an electric power supply device, and this electric power supply device, the electric motor 60A, and the hydraulic pump 1 constitute a power source. In addition, the power source drives the electric motor 60A by electric power supply from the electric power supply device (battery 62), and generates power by driving the hydraulic pump 1 by the electric motor 60A.
Functions of the controller 50A in the second embodiment will next be described.
The controller 50A performs power reduction control by reducing the electric power supplied to the electric motor 60A and thus reducing the rotation speed of the electric motor 60A.
Details of the above-described functions of the controller 50A will be described in the following.
In
Functions of the power computing section 50cA in the second embodiment will next be described.
In
A computation flow of the power reduction determining section 50c-5A in the second embodiment will next be described.
In
In step S510, the power reduction determining section 50c-5A sets the power reduction flag F50(t) true, and at the same time, the power reduction determining section 50c-5A sets a target current upper limit value for control to a target current upper limit value for power reduction control, which is lower than a normal target current upper limit value. The normal target current upper limit value is a value obtained by dividing a target electric power indicated by the target electric power indicating device 77A by a rated voltage of the battery 62. Then, the power reduction determining section 50c-5A transmits the target current upper limit value for power reduction control to the battery output power control panel 63. The same processing as in step S510 is performed also in step S512.
In step S511, the power reduction determining section 50c-5A sets the power reduction flag F50(t) false, and at the same time, the power reduction determining section 50c-5A sets the target current upper limit value for control to the normal target current upper limit value calculated from the target electric power indicated by the target electric power indicating device 77A. Then, the power reduction determining section 50c-5A transmits the normal target current upper limit value to the battery output power control panel 63. The same processing as in step S511 is performed also in step S513.
The second embodiment configured as described above, in which the power source is constituted by the battery 62 (electric power supply device), the electric motor 60A, and the hydraulic pump 1, provides effects similar to those of the first embodiment. Specifically, it is possible to perform power reduction control during non-operation of the control levers and make a smooth transition to an operation desired to be performed at a time of a return to a normal power state, and suppress electric power consumption of the electric motor 60A and thus reduce an amount of electric power consumed by the electric motor 60A (energy consumption) when the control lever(s) 14 and/or 34 is moved by an erroneous operation.
A third embodiment of the present invention will be described with reference to
A configuration of a driving system in the third embodiment will first be described.
In
The battery 62 is connected to a positive electrode side wire 81 and a negative electrode side wire 82. Inverters 83, 84, 85, and 86 are connected in parallel to the positive electrode side wire 81 and the negative electrode side wire 82.
The inverter 83 drives an electric motor 87. The electric motor 87 further drives a cylinder 91 (boom cylinder). The cylinder 91 performs expansion and contraction by converting a rotary motion of the electric motor 87 into a rectilinear motion by a rack-and-pinion mechanism or the like. The inverter 83 receives a signal transmitted from the angle sensor 72, and controls the electric motor 87 so as to achieve a rotation speed corresponding to the information of the signal.
The inverter 84 drives an electric motor 88. The electric motor 88 further drives a cylinder 92 (arm cylinder). The cylinder 92 performs expansion and contraction by converting a rotary motion of the electric motor 88 into a rectilinear motion by a rack-and-pinion mechanism or the like. The inverter 84 receives a signal transmitted from the angle sensor 73, and controls the electric motor 88 so as to achieve a rotation speed corresponding to the information of the signal.
The inverter 85 drives an electric motor 89. The electric motor 89 further drives a cylinder 93 (bucket cylinder). The cylinder 93 performs expansion and contraction by converting a rotary motion of the electric motor 89 into a rectilinear motion by a rack-and-pinion mechanism or the like. The inverter 85 receives a signal transmitted from the angle sensor 74, and controls the electric motor 89 so as to achieve a rotation speed corresponding to the information of the signal.
The inverter 86 drives an electric motor 90 (swing motor). The inverter 86 receives a signal transmitted from the angle sensor 75, and controls the electric motor 90 so as to achieve a rotation speed corresponding to the information of the signal.
Here, the battery 62 is an electric power supply device, and this electric power supply device constitutes a power source. In addition, the electric motor 87 and the cylinder 91, the electric motor 88 and the cylinder 92, the electric motor 89 and the cylinder 93, and the electric motor 90 are each an electric actuator, and constitute a plurality of actuators that are actuated by receiving power from the power source. The inverters 83, 84, 85, and 86 constitute a power distributing device that distributes the power to the plurality of actuators (the electric motor 87 and the cylinder 91, the electric motor 88 and the cylinder 92, the electric motor 89 and the cylinder 93, and the electric motor 90).
Configurations of control lever devices in the third embodiment will next be described with reference to
In
The angle sensors 72, 73, 74, and 75 constitute a plurality of operation state sensors that detect the operation states of the control lever devices 314 and 334.
The angle sensors 72, 73, 74, and 75 are electrically connected to the controller 50B, and transmit angle information to the controller 50B.
In addition, the angle sensor 72 is electrically connected to the inverter 83, the angle sensor 73 is electrically connected to the inverter 85, the angle sensor 74 is electrically connected to the inverter 84, and the angle sensor 75 is electrically connected to the inverter 86. The angle sensors 72, 73, 74, and 75 transmit the angle information to the inverters 83, 85, 84, and 86, respectively.
Also when the lever 14 is inclined in the right direction 24r or the left direction 24b, and the lever 34 is inclined in the right direction 34b or the left direction 34r and in the forward direction 44l or the rearward direction 44r, the target rotation speeds of the electric motors 88, 89, and 90 similarly change.
The control lever devices 314 and 334 instruct amounts of power to be distributed to the plurality of actuators (the electric motor 88 and the cylinder 92, the electric motor 89 and the cylinder 93, and the electric motor 90) to the power distributing device (inverters 83, 84, 85, and 86) on the basis of the angle information detected by the angle sensors 72, 73, 74, and 75 as described above.
Functions of the controller 50B in the third embodiment will next be described.
In
The sensor signal converting section 50aB receives signals sent from the angle sensors 72 to 75 and the switch 76, and converts the signals into angle information and switch flag information. The sensor signal converting section 50aB transmits the converted angle information and the converted switch flag information to the power computing section 50cB.
The constant and table storage section 50b stores constants and tables necessary for calculation. The constant and table storage section 50b transmits the constants and the tables to the power computing section 50cB.
The power computing section 50cB receives the angle information and the switch flag information transmitted from the sensor signal converting section 50aB, the constant information and the table information transmitted from the constant and table storage section 50b, and the target voltage information transmitted from the target voltage indicating device 77B, and computes a target voltage for control of the battery 62. Then, the power computing section 50cB outputs a command signal of the target voltage for control to the battery output power control panel 63. The battery output power control panel 63 controls the voltage of the battery 62 on the basis of the value.
Sensor signal conversion processing in the sensor signal converting section 50aB will next be described.
As shown in
Functions of the power computing section 50cB in the third embodiment will next be described.
In
Functions of the lever 14 operation state determining section 50c-1B in the third embodiment will next be described.
The computation flow of the lever 14 operation state determining section 50c-1B is different from the computation flow of the lever 14 operation state determining section 50c-1 in the first embodiment, which is shown in
In step S110, the lever 14 operation state determining section 50c-1B determines whether the absolute value of the sensor value A72(t) is smaller than a threshold value Ath. When the absolute value of the sensor value A72(t) is smaller than the threshold value Ath, the lever 14 operation state determining section 50c-1B determines Yes, and proceeds to the processing of step S111. When the absolute value of the sensor value A72(t) is equal to or larger than the threshold value Ath, the lever 14 operation state determining section 50c-1B determines No, and proceeds to the processing of step S107.
In step S111, the lever 14 operation state determining section 50c-1B determines whether the absolute value of a sensor value A73(t) is smaller than the threshold value Ath. When the absolute value of the sensor value A73(t) is smaller than the threshold value Ath, the lever 14 operation state determining section 50c-1B determines Yes, and proceeds to the processing of step S106. When the absolute value of the sensor value A73(t) is equal to or larger than the threshold value Ath, the lever 14 operation state determining section 50c-1B determines No, and proceeds to the processing of step S107.
In step S106, the lever 14 operation state determining section 50c-1B sets the lever 14 non-operation flag F14(t) true. In step S107, the lever 14 operation state determining section 50c-1B sets the lever 14 non-operation flag F14(t) false. These pieces of flag information are transmitted to the lever 14 non-operation time measuring section 50c-3 and the power non-reduction time measuring section 50c-7.
Functions of the lever 34 operation state determining section 50c-2B in the third embodiment will next be described.
The computation flow of the lever 34 operation state determining section 50c-2B is different from the computation flow of the lever 34 operation state determining section 50c-2 in the first embodiment, which is shown in
In step S210, the lever 34 operation state determining section 50c-2B determines whether the absolute value of a sensor value A74(t) is smaller than the threshold value Ath. When the absolute value of the sensor value A74(t) is smaller than the threshold value Ath, the lever 34 operation state determining section 50c-2B determines Yes, and proceeds to the processing of step S211. When the absolute value of the sensor value A74(t) is equal to or larger than the threshold value Ath, the lever 34 operation state determining section 50c-2B determines No, and proceeds to the processing of step S207.
In step S211, the lever 34 operation state determining section 50c-2B determines whether the absolute value of a sensor value A75(t) is smaller than the threshold value Ath. When the absolute value of the sensor value A75(t) is smaller than the threshold value Ath, the lever 34 operation state determining section 50c-2B determines Yes, and proceeds to the processing of step S206. When the absolute value of the sensor value A75(t) is equal to or larger than the threshold value Ath, the lever 34 operation state determining section 50c-2B determines No, and proceeds to the processing of step S207.
In step S206, the lever 34 operation state determining section 50c-2B sets the lever 34 non-operation flag F34(t) true. In step S207, the lever 34 operation state determining section 50c-2B sets the lever 34 non-operation flag F34(t) false. These pieces of flag information are transmitted to the lever 34 non-operation time measuring section 50c-4 and the power non-reduction time measuring section 50c-7.
Thus, the lever 14 operation state determining section 50c-1B determines whether the lever 14 is operated from the sensor value A72(t) and the sensor value A73(t), and outputs the lever 14 non-operation flag F14(t). The lever 34 operation state determining section 50c-2B determines whether the lever 34 is operated from the sensor value A74(t) and the sensor value A75(t), and outputs the lever 34 non-operation flag F34(t).
The lever 14 non-operation time measuring section 50c-3 measures a lever 14 non-operation time Tu14 (t) and the time information is transmitted to the power reduction determining section 50c-5B. The lever 34 non-operation time measuring section 50c-4 measures a lever 34 non-operation time Tu34(t) and the time information is transmitted to the power reduction determining section 50c-5B.
A computation flow of the power reduction determining section 50c-5B in the third embodiment will next be described.
In
In step S520, the power reduction determining section 50c-5B sets the power reduction flag F50(t) true, and at the same time, the power reduction determining section 50c-5B sets the target voltage for control to a target voltage for power reduction control, which is lower than a normal target voltage. The target voltage is a target voltage indicated by the target voltage indicating device 77B. Then, the power reduction determining section 50c-5B transmits the target voltage for power reduction control to the battery output power control panel 63. The same processing as in step S520 is performed also in step S522.
In step S521, the power reduction determining section 50c-5B sets the power reduction flag F50(t) false, and at the same time, the power reduction determining section 50c-5B sets the target voltage for control to the normal target voltage indicated by the target voltage indicating device 77B. Then, the power reduction determining section 50c-5B transmits the normal target voltage to the battery output power control panel 63. The same processing as in step S521 is performed also in step S523.
The third embodiment configured as described above, in which the power source is constituted by the battery 62 (electric power supply device) and the actuators are constituted by electric actuators including the electric motors 87 to 90, provides effects similar to those of the first embodiment. Specifically, it is possible to perform power reduction control during non-operation of the control levers and make a smooth transition to an operation desired to be performed at a time of a return to a normal power state, and reduce electric power consumption of the battery 62 and thus reduce an amount of electric power consumed by the battery 62 (energy consumption) when the control lever(s) 14 and/or 34 is moved by an erroneous operation.
In the first embodiment, description has been made of a case where the control lever devices 114 and 134 are of a hydraulic pilot type including pilot valves, and the operation state sensors are the pressure sensors 17b, 17r, 27b, 27r, 37b, 37r, 47l, and 47r that detect the operation pressures generated by the pilot valves. However, the operation states sensors may be of other configurations.
For example, the operation states of the control lever devices may be detected by providing one or a plurality of signal pressure generating lines that introduce the delivery oil of the pilot pump 51 shown in
In
The signal pressure generating valve 78a can be switched by operation pressure generated in the lines 16b and 16r shown in
The same is true for the signal pressure generating valves 78b, 78c, and 78d. When the lever 14 shown in
The controller 50 determines whether at least one of the lever 14 and the lever 34 is operated on the basis of the signals transmitted from the pressure sensor 70.
In
When the lever 14 is operated and thereby an operation pressure is generated in one of the lines 16b and 16r, and the operation pressure is introduced to one of the lines 16b-1 and 16r-1, the signal pressure generating valve 79a is opened, and the signal pressure generating line 52b is set to a tank pressure. The pressure sensor 70 measures the pressure as a signal pressure, and transmits a signal to the controller 50.
The same is true for the signal pressure generating valves 79b, 79c, and 79d. When the lever 14 is operated and thereby an operation pressure is generated in one of the lines 26b and 26r, the lines 36b and 36r, and the lines 46b and 46r, the signal pressure generating valve 79b, 79c, or 79d is opened, and the signal pressure generating line 52b is set at the tank pressure. The pressure sensor 70 measures the pressure as a signal pressure, and transmits a signal to the controller 50.
The controller 50 determines whether at least one of the lever 14 and the lever 34 is operated on the basis of the signals transmitted from the pressure sensor 70.
When the operation state sensor is configured as described above, one pressure sensor 70 suffices, and the configuration of the operation state sensor and the signal processing of the controller 50 can be simplified.
In addition, as another modification of the operation state sensor, even in a case where the control lever devices 114 and 134 are of a hydraulic pilot type as shown in
In the first embodiment, the power source of the driving system has a configuration including the engine 6. In the second embodiment, the power source of the driving system has a configuration including the direct-current electric motor 60A. However, a configuration including an alternating-current electric motor may be adopted in place of the engine 6 or the direct-current electric motor 60A.
A driving system according to the present modification in
The controller 50 calculates a target rotation speed for control by performing processing similar to that of the controller 50 shown in
Such a configuration can also provide effects similar to those of the first and second embodiments.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/013851 | 3/26/2020 | WO |