JP6514895B2 - Drive control system for working machine, working machine including the same, and drive control method thereof - Google Patents

Description

  The present invention drives a structure of a working machine by causing a hydraulic motor and a motor to cooperate with each other, and a drive control system which regenerates energy by the motor when braking the structure, a working machine including the same, and the same The present invention relates to a drive control method.

  BACKGROUND Working machines such as hydraulic shovels and cranes are publicly known, and these working machines can perform various work by moving work equipment such as shovels and cranes. These working machines have a lower traveling body, on which an upper revolving body is pivotably provided. A work device is attached to the upper swing body, and the direction of the work device can be changed by turning the upper swing body. The work machine also includes a drive control system to pivot the upper pivoting body.

  Patent Document 1 discloses an example of a drive control system. The drive control system of Patent Document 1 includes a hydraulic motor and a motor. The motor and the hydraulic motor cooperate with one another to pivot the upper swing body. The hydraulic motor is driven by pressure oil discharged from the hydraulic pump, and the electric motor is driven by electric power supplied from the storage device. In addition, the electric motor has a power generation function, converts kinetic energy of the upper swing body at the time of turning into electric power, and brakes the upper turn. The converted power is stored in the power storage device and used for the next driving.

JP 2012-62653 A

  In a system including an electric motor as in the drive control system of Patent Document 1, a driving device (for example, an inverter) for driving the electric motor is provided. The drive device has a conversion function such as AC / DC conversion or voltage conversion, and the conversion function increases the rotational speed of the motor to accelerate the upper structure or causes the motor to generate electric power to brake the upper structure. It is supposed to

  Drive power is supplied to the drive device and the motor from the power storage device regardless of the presence or absence of the drive, and energy is steadily lost. In other words, drive power (so-called standby power) is supplied to the drive unit and the motor even at the time of constant speed turning or stopping by hydraulic drive that does not require the motor to generate torque, and as a result, steady loss occurs. ing. Then, the power stored in the power storage device may be consumed regardless of the swing acceleration of the upper swing structure, and the overall regeneration efficiency of the drive control system may be reduced.

  Therefore, an object of the present invention is to provide a drive control system capable of improving the regeneration efficiency.

  The drive control system for a working machine according to the present invention can be discharged and charged with a hydraulic motor that operates a structure by receiving hydraulic fluid supply, and a hydraulic fluid supply device that supplies hydraulic fluid to the hydraulic motor. An electric storage device and an electric motor that operates the structure of the working machine in cooperation with the hydraulic motor by supplying power from the electric storage device, and generates electric power to regenerate the electric storage device to brake the structure. And a drive device that operates by supplying drive power to drive the motor and adjusts the supplied power to the motor and the regenerative power to the storage device; and setting a motor target torque of the motor, And a controller for supplying the drive power to the drive device according to the motor target torque to control the operation of the drive device, the controller including an electric power including that the motor target torque is zero. If it is determined that satisfy the stop condition, but adapted to stop the supply of the drive power to the drive device.

  According to the present invention, it is possible to prevent power consumption of the storage device due to steady loss of the drive device and the motor during constant speed swing or stop by hydraulic drive which does not require the motor to generate torque. . Thus, conventionally, the power consumed by the steady loss can be used when the structure is subsequently operated, and the regeneration efficiency of the drive control system can be improved.

  In the above invention, the control device acquires the storage amount of the power storage device, makes the motor target torque zero when the storage amount is equal to or less than a predetermined amount, and stops supply of driving power to the drive device. It is also good.

  According to the above configuration, it is possible to prevent excessive discharge of the power of the power storage device due to steady loss of the drive device and the motor.

In the above invention, a speed detector for detecting the operating speed of the structure is provided.
The controller sets the motor target torque to zero when it determines that the power stop condition including that the structure decelerates and the operation speed detected by the speed detector is equal to or less than a predetermined speed is satisfied. The supply of drive power to the drive device may be stopped.

  According to the above configuration, when the operating speed of the structure at the time of the deceleration braking becomes a predetermined speed, for example, a speed at which the steady loss becomes larger than the power obtained from the motor, Power consumption can be prevented. Thus, conventionally, the power consumed by the steady loss can be used when the structure is subsequently operated, and the regeneration efficiency of the drive control system can be improved.

  A work machine according to the present invention includes the drive control system according to any one of the above and the structure, the structure is a swing body, and the electric motor and the hydraulic motor reduce a reduction gear. The rotating body is rotationally driven through the interposition.

  According to the above configuration, it is possible to realize a working machine having the above-described effects.

  The drive control method of the drive control system according to the present invention is supplied from an electric motor and a pressure liquid supply device which operate the structure by power supply from the power storage device and generate power to regenerate the power storage device and brake the structure. The drive unit operates with the hydraulic motor driven by the pressure liquid in cooperation with the hydraulic motor, and the drive device operated by the supply of the drive power supplies the supplied power of the motor and the regenerated power of the storage device to the motor target torque A drive control method of a drive control system adjusted according to the setting step of setting a motor target torque of the motor, and whether a power stop condition including that the motor target torque is zero is satisfied or not When it is determined in the first determination step of determining and the first determination step that the power stop condition is satisfied, the power supply from the power storage device to the drive device is stopped before A method and a stopping step of stopping the driving of the driving device.

  According to the present invention, it is possible to prevent power consumption of the storage device due to steady loss of the drive device and the motor during constant speed swing or stop by hydraulic drive which does not require the motor to generate torque. . Thus, conventionally, the power consumed by the steady loss can be used when the structure is subsequently operated, and the regeneration efficiency of the drive control system can be improved.

  In the above invention, the speed detecting step of detecting the operating speed of the structure, and braking the structure by the electric motor to decelerate the operating speed detected by the operating speed detector is equal to or less than a predetermined speed. And a second determination step of determining whether or not the power stop condition including the above is satisfied, and the stop step, when it is determined that the power stop condition is satisfied in the second determination step, the motor target torque May be zeroed, power supply from the power storage device to the drive device may be stopped, and driving of the drive device may be stopped.

  According to the above configuration, it is possible to prevent power consumption of the power storage device due to steady loss of the drive device and the motor during deceleration braking. Thus, conventionally, the power consumed by the steady loss can be used when the structure is subsequently operated, and the regeneration efficiency of the drive control system can be improved.

  According to the present invention, the regeneration efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows a hydraulic shovel provided with the drive control system which concerns on 1st and 2nd embodiment of this invention. FIG. 2 is a hydraulic circuit diagram showing a hydraulic circuit of a drive control system of the first and second embodiments provided in the hydraulic shovel of FIG. 1. FIG. 3 is an electric circuit diagram showing an electric circuit of a drive device provided in the drive control system of FIG. 2; The speed command input from the operation lever provided in the drive control system of FIG. 2, the actual speed of the rotating body in response to the speed command, the output torque of the motor, the assist torque of the hydraulic motor, the output torque of the electric oil swing motor, and the storage energy It is a sequence diagram showing change. The speed command input from the operation lever of the drive control system of the second embodiment, the actual speed of the rotating body in response to the speed command, the output torque of the motor, the assist torque of the hydraulic motor, the output torque of the electric oil swing motor, and the stored energy It is a sequence diagram which shows a time-dependent change of. It is a flowchart which shows the procedure of the deceleration control processing which the drive control system of 2nd Embodiment performs.

  Hereinafter, the configurations of the drive control systems 1 and 1A according to the first and second embodiments of the present invention and the hydraulic shovel 2 including the same will be described with reference to the above-described drawings. In addition, the concept of the direction in the embodiment is used for the convenience of description, and with respect to the structures of the drive control systems 1 and 1A and the hydraulic shovel 2, restricting the arrangement, the direction, and the like of those configurations to that direction It does not imply. Moreover, the structure and control of drive control systems 1 and 1A and hydraulic excavator 2 which are explained below are only one embodiment of the present invention, and the present invention is not limited to the embodiment, and within the scope of the present invention It is possible to add, delete and change.

[Hydraulic shovel]
As shown in FIG. 1, a hydraulic shovel 2 which is an example of a working machine can perform various operations such as excavation and transportation by an attachment attached to a tip, for example, a bucket 3. The hydraulic shovel 2 has a traveling device 4 such as a crawler, and the revolving structure 5 is placed on the traveling device 4. A driver's seat 5 a on which the driver gets on is formed in the revolving structure 5 which is a structural body, and a bucket 3 is further provided via a boom 6 and an arm 7. The swing body 5 configured in this manner is configured to be swingable with respect to the traveling device 4. In addition, the hydraulic shovel 2 has a drive control system 1 for driving the swing body 5 in a swing manner. Hereinafter, the configuration of the drive control system 1 will be described with reference to FIG.

[Drive control system]
The drive control system 1 mainly includes a hydraulic pump 10, a control valve 11, a remote control valve 12, two electromagnetic pressure reducing valves 13 and 14, two electromagnetic relief valves 15 and 16, and an electric oil swing motor 17 Is equipped. The hydraulic pump 10, which is a hydraulic pump, is a variable displacement swash plate type hydraulic pump, and is driven by an engine (not shown) to discharge hydraulic fluid. The hydraulic pump 10 has a swash plate 10a, and by tilting the swash plate 10a, the discharge amount of the hydraulic oil can be changed. A regulator 18 is connected to the swash plate 10a.

The regulator 18 has a servo piston not shown. The servo piston is connected to the swash plate 10a, and the swash plate 10a is inclined at an inclination angle corresponding to the position of the servo piston. Further, the regulator 18 is connected to the pilot pump 20 via the electromagnetic pressure reducing valve 19, and the servo piston moves to a position corresponding to the command pressure p ₀ discharged from the electromagnetic pressure reducing valve 19. . The electromagnetic pressure reducing valve 19, and outputs a command pressure p ₀ which was reduced to a pressure corresponding to the command signal applied thereto. Therefore, the swash plate 10a tilts to the tilt angle according to the command signal, and the hydraulic oil having a flow rate according to the tilt angle is discharged from the discharge port 10b of the hydraulic pump 10. A control valve 11 is connected to the discharge port 10 b via a discharge passage 21.

  The control valve 11 is a spool valve provided with a spool 22. By moving the spool 22, the control valve 11 can change the flow rate of hydraulic fluid flowing to the connection destination and the connection destination of the hydraulic pump 10. Further, two pilot passages 23 and 24 are connected to the control valve 11, and the remote control valve 12 is connected via the pilot passages 23 and 24.

  The remote control valve 12 which is an input device is a device for inputting a target swing speed. The input device is not limited to the hydraulic type, and may be an electric type. The remote control valve 12 has a control lever 25. The control lever 25 is configured to be tiltable in one direction and the other in a predetermined direction. The remote control valve 12 is configured to output, to the pilot passages 23 and 24 corresponding to the tilting direction of the control lever 25, pilot oil of a pressure corresponding to the amount of tilt (adjustment value) of the control lever 25. The pilot pressure sensors 26 and 27 are respectively connected to the pilot passages 23 and 24, and the pilot pressure sensors 26 and 27 are configured to detect the hydraulic pressure output from the remote control valve 12.

Further, electromagnetic pressure reducing valves 13 and 14 intervene in the pilot passages 23 and 24, respectively. The electromagnetic pressure reducing valves 13 and 14 are so-called normally open type pressure reducing valves, and the pressure corresponding to the current (command value) supplied to the electromagnetic pressure reducing valves 13 and 14 by reducing the pressure of the pilot oil output from the remote control valve 12 It is configured to adjust to. The pilot oil output from the remote control valve 12 is led to both ends of the spool 22 by the pilot passages 23 and 24, respectively. The spool 22 receives pilot pressures p ₁ and p ₂ at both ends thereof, and is moved to a position corresponding to the pilot pressures p ₁ and p ₂ . The control valve 11 changes the flow rate of hydraulic fluid flowing to the connection destination and the connection destination of the hydraulic pump 10 by moving the spool 22.

  The control valve 11 has four ports 11a to 11d. The first port 11a is connected to the hydraulic pump 10 through the discharge passage 21, and the second port is a second port. 11 b is connected to the tank 29 via the tank passage 30. Further, the third port 11 c and the fourth port 11 d are connected to the electric oil swing motor 17 via the first oil passage 31 and the second oil passage 32 respectively. The connection destinations of these four ports 11 a to 11 d change according to the position of the spool 22. That is, when the spool 22 is located at the neutral position M1, the first port 11a and the second port 11b are connected, and the hydraulic pump 10 is in the unloading state. When the spool 22 moves to the first offset position A1, the first port 11a and the third port 11c are connected, and the second port 11b and the fourth port 11d are connected. On the other hand, when the spool 22 moves to the second offset position A2, the first port 11a and the fourth port 11d are connected, and the second port 11b and the third port 11c are connected. As described above, when the spool 22 is positioned at the first or second offset position A1, A2, the hydraulic pump 10 and the electric oil swing motor 17 are connected, and the hydraulic oil is supplied to the electric oil swing motor 17.

  The electric oil swing motor 17 has a hydraulic motor 33, an electric motor 34 and an output shaft 35. The output shaft 35 is connected to the rotating body 5 via a reduction gear (not shown), and the rotating body 5 is rotated by rotating the output shaft 35. The hydraulic motor 33 and the motor 34 are integrally configured, and cooperate to rotate the output shaft 35. Hereinafter, the configurations of the hydraulic motor 33 and the motor 34 will be described in detail.

  The motor 34 is, for example, a three-phase alternating current motor, and has a stator and a rotor (not shown). The rotor is provided non-rotatably on the output shaft 35, and the stator is provided non-rotatably on the hydraulic motor 33. The rotor and the stator are configured to be relatively rotatable, and rotation according to the frequency of the alternating current is performed by supplying a three-phase alternating current (hereinafter, also simply referred to as “alternating current”) to coils of the stator. The output shaft 35 is rotated forward or backward at the speed. In addition, the motor 34 has a power generation function of converting the rotational energy (kinetic energy) of the output shaft 35 into electrical energy to generate an alternating current, and generates power so as to decelerate the output shaft 35 that rotates. It has become. The motor 34 configured in this manner is electrically connected to the drive device 36 and is further electrically connected to the storage battery 28 via the drive device 36. The storage battery 28 is configured to be able to store electric power, and is configured to discharge a direct current to the drive device 36.

  As shown in FIG. 3, the drive device 36 has a boost chopper unit 36a and an inverter unit 36b. The step-up chopper unit 36 a is connected to the storage battery 28, and has a function of boosting the DC current supplied from the storage battery 28 and stepping down the DC current supplied to the storage battery 28. Further, an inverter unit 36b is connected to the step-up chopper unit 36a, and a direct current boosted by the step-up chopper unit 36a is led to the inverter unit 36b.

  The inverter unit 36 b is configured of a plurality of switching elements. The inverter unit 36 b is supplied with, for example, pulse width modulated drive power from the control device 50 described later, and switches the switching element on and off according to the drive power to convert direct current into alternating current to convert the motor It is designed to supply 34. At this time, the inverter unit 36 b adjusts the power supplied to the motor 34 according to the pulse width of the drive power, specifically, changing the frequency of the alternating current supplied to the motor 34 to obtain a desired acceleration torque for the motor 34. Can be generated. Furthermore, the inverter unit 36 b is configured to convert an alternating current generated by the motor 34 into a direct current by switching on and off the switching element according to the driving power. The drive device 36 is configured to lead the converted direct current to the capacitor 28 via the step-up chopper unit 36 a and store the direct current in the capacitor 28. Under the present circumstances, the inverter part 36b adjusts the regenerated electric power to the electrical storage device 28 according to the pulse width of drive power, and, specifically, changes the frequency of the alternating current generated by the electric motor 34, and desired braking torque for the electric motor 34 Can be generated (that is, regeneration operation can be performed).

  As described above, the drive device 36 can switch on and off the switching elements of the step-up chopper unit 36 a and the inverter unit 36 b to supply power to the motor 34 or charge the capacitor 28. On the other hand, drive device 36 cuts off the supply of drive power to boost chopper portion 36 a and inverter portion 36 b by completely turning off the functions of switching elements of boost chopper portion 36 a and inverter portion 36 b. Steady-state loss can be suppressed. Thus, the drive device 36 is switched between the servo-on state in which the drive power is supplied and the servo-off state in which the supply of the drive power is stopped.

  The hydraulic motor 33 is, for example, a fixed displacement hydraulic motor, and has two supply and discharge ports 33a and 33b. The first oil passage 31 is connected to the first supply and discharge port 33a, and the second oil passage 32 is connected to the second supply and discharge port 33b. When hydraulic fluid is supplied to the first supply and discharge port 33a, the hydraulic motor 33 causes torque corresponding to the hydraulic pressure and flow rate of the hydraulic fluid to act on the output shaft 35 in the positive direction, and operates on the second supply and discharge port 33b. When oil is supplied, a torque corresponding to the hydraulic pressure and flow rate of the hydraulic fluid is applied to the output shaft 35 in the reverse direction. That is, the hydraulic motor 33 applies an assist torque corresponding to the hydraulic pressure and the flow rate of the supplied hydraulic oil to the output shaft 35 to assist the rotation of the output shaft 35. The hydraulic oil for driving the hydraulic motor 33 is supplied to the hydraulic motor 33 by the hydraulic oil supply device 9.

  The hydraulic fluid supply device 9, which is a hydraulic fluid supply device, mainly includes the hydraulic pump 10 described above, the control valve 11, and the two electromagnetic pressure reducing valves 13 and 14, and further includes the two electromagnetic relief valves 15 and 16. doing. The electromagnetic relief valves 15 and 16 are connected to the first oil passage 31 and the second oil passage 32, respectively, and the hydraulic oil of the first oil passage 31 and the second oil passage 32 is stored in the tank 29 via the electromagnetic relief valves 15 and 16. It is arranged to be able to The electromagnetic relief valves 15, 16 arranged in this manner have a pressure control function of adjusting the hydraulic pressure of the hydraulic fluid discharged to the tank 29 to a pressure corresponding to the current (command value) flowing therethrough. In the hydraulic oil supply device 9, the control valve 11 shuts off between the oil paths 31 and 32 on the discharge side and the tank 29 to discharge the hydraulic oil through the electromagnetic relief valves 15 and 16, thereby allowing the output shaft 35 to Can be braked and decelerated. The braking force acting on the output shaft 35 can be changed by adjusting the hydraulic pressure of the oil passages 31 and 32 on the discharge side with the electromagnetic relief valves 15 and 16.

  Further, the hydraulic oil supply device 9 has relief valves 38 and 39 and check valves 40 and 41, and the relief valves 38 and 39 and check valves 40 and 41 have a first oil passage 31 and a second oil. Each path 32 is connected. The relief valves 38 and 39 are configured to open the oil passages 31 and 32 to the tank 29 when the hydraulic oil flowing through the oil passages 31 and 32 exceeds a set pressure. It is suppressing the damage. The check valves 40 and 41 are connected to the tank 29 to allow the flow of hydraulic fluid from the tank 29 to the respective oil passages 31 and 32 and to block the flow of hydraulic fluid in the reverse direction. . As a result, the hydraulic oil which runs short when driving the hydraulic motor 33 can be introduced from the tank 29 to the hydraulic motor 33 via the check valves 40 and 41.

Further, oil pressure sensors 42 and 43 are provided in the first oil passage 31 and the second oil passage 32, respectively, and the oil pressure supplied to the supply and discharge ports 33a and 33b of the hydraulic motor 33 is each oil pressure sensor 42 and 43. Has been detected by Further, in the electric oil swing motor 17, the rotation speed sensor 44 is provided on the output shaft 35, and the rotation speed sensor 44 which is a speed detector measures the rotation speed of the output shaft 35 (that is, the rotation speed of the output shaft 35 ) To detect. The sensors 42 to 44 and the pilot pressure sensors 26 and 27 described above are electrically connected to the control device 50 that controls various configurations, and transmit the detected values to the control device 50. Specifically, the hydraulic pressure detected by the hydraulic pressure sensors 42 and 43 is input to the control device 50, and the differential pressure thereof becomes the differential pressure feedback signal DP. Further, the pilot pressure detected by the pilot pressure sensors 26 and 27 is input to the control device 50, and their differential pressure becomes the speed command signal _VCOM . Further, the rotational speed detected by the rotational speed sensor 44 is input to the control device 50, and becomes the speed feedback signal _VFB .

  The control device 50 is electrically connected to the storage battery 28, and detects the storage amount of the storage battery 28 based on the power output from the storage battery 28. Further, the control device 50 receives power supply from the storage battery 28 and is operated by the supplied power. Furthermore, the control device 50 is electrically connected to a plurality of configurations as described later, and supplies power (signal) to each connected configuration to drive each configuration.

  Specifically, the control device 50 is electrically connected to the electromagnetic pressure reducing valves 13 and 14, the electromagnetic relief valves 15 and 16, the electromagnetic pressure reducing valve 19, and the drive device 36, and further, the respective sensors 26, 27, 42 to It is also connected to 44. Control device 50 controls the operation of each valve 13-16, 19 according to the detection result of each sensor 26, 27, 42-44 and generates a desired assist torque (acceleration torque or braking torque) in hydraulic motor 33. It is supposed to Further, the control device 50 is configured to supply drive power to the drive device 36 (specifically, the inverter unit 36 b), and controls the operation of the drive device 36 by adjusting the supplied drive power to achieve a desired operation. An acceleration torque or a braking torque is generated in the motor 34. As described above, the control device 50 controls the operations of the hydraulic motor 33 and the motor 34 to cause the swing body 5 to swing in a desired motion (rotational direction, speed, and torque).

  Further, the control device 50 can cause the hydraulic motor 33 and the motor 34 to function as a brake and brake the swinging rotating body 5 by controlling the operations of the valves 13 to 16 and 19 and the drive device 36 respectively. It has become. Furthermore, the control device 50 can stop the supply of drive power to the drive device 36 and switch the drive device 36 to the servo off state. Hereinafter, the control operation of the control device 50 will be described with reference to the sequence diagram of FIG.

[Control operation of control unit]
The control device 50 starts the drive control process when the power of the hydraulic shovel 2 is turned on. Control device 50 first calculates the target total torque based on the speed difference between speed command signal _VCOM and speed feedback signal _VFB, and then generates from motor 34 among the target total torque based on the storage amount of capacitor 28. The torque to be driven is set as the motor target torque (acceleration torque or braking torque).

  When the storage amount of the storage battery 28 decreases and becomes equal to or less than the predetermined amount, the control device 50 sets the motor target torque at the time of driving the revolving unit 5 to zero. Here, the predetermined amount is a storage amount that can not drive the motor 34 efficiently by the storage battery 28. Thus, the motor target torque is set.

  When the power stop condition including that the set motor target torque is zero is satisfied, control device 50 stops the supply of drive power to drive device 36 and switches the state of drive device 36 to the servo off state. (Or maintain). The motor target torque being zero also includes that the motor target torque is at or near zero. As a result, it is possible to eliminate the steady loss generated by the drive device 36 and the motor 34 at the time of acceleration, constant speed turning and stop when there is no need to generate torque in the motor, and the capacitor at acceleration, constant speed turning and stop Power consumption can be prevented at 28. Further, when the storage amount of the storage battery 28 becomes equal to or less than the predetermined amount, the motor target torque is set to zero, so that the supply of the drive power to the drive device 36 is also stopped in this case. Thereby, it is possible to prevent the excessive discharge of the power of the storage device 28 due to the steady loss of the drive device 36 and the motor 34.

  On the other hand, when the power stop condition including that the set motor target torque is zero is not satisfied, the control device 50 switches (or maintains) the state of the drive device 36 to the servo-on state and sets the motor 34 to the motor target. The operation of the drive 36 is controlled to generate a torque. For example, as shown in FIG. 4, when the operation lever 25 is operated to one side or the other side, the control device 50 supplies drive power to the drive device 36 to accelerate the rotating body 5 to accelerate torque from the motor 34 (motor target The torque is output, and the rotating body 5 is accelerated to a desired speed. Further, as shown in FIG. 4, when the control lever 25 is returned to the neutral position, the drive power is supplied to the drive device 36 to brake the swing body 5 to cause the motor 34 to generate electric power. And the rotating body 5 is braked to a desired speed.

  That is, the control device 50 supplies drive power according to the motor target torque to the drive device 36 to adjust the supplied power of the motor 34 or the regenerated power from the motor 34, and causes the motor 34 to accelerate or brake the revolving structure 5.

  In the drive control system 1 that implements such drive control, it is possible to prevent power consumption of the storage device 28 due to steady loss of the drive device 36 and the motor 34 during constant speed turning, stopping and low storage capacity of the swing structure 5. it can. Thereby, the electric power (FIG. 4 shaded portion in FIG. 4) is used to turn the swing body 5 next (refer to the dotted line portion in the stored energy in FIG. 4). It can be used as Therefore, the regeneration efficiency of the drive control system 1 can be further improved.

[About the second embodiment]
The drive control system 1A of the second embodiment has the same configuration as the drive control system 1 of the first embodiment, but executes the following deceleration control processing in addition to the above-described drive control processing. It is supposed to be. In the following, the point of the deceleration control process that is different from the drive control system 1 of the first embodiment in the drive control system 1A of the second embodiment will be described with reference to FIGS. 5 and 6. The configuration of the drive control system 1A of the second embodiment that is the same as the configuration of the drive control system 1 of the first embodiment is given the same reference numerals and explanation thereof is omitted.

In the drive control system 1A of the second embodiment, when the control lever 25 is tilted to one side as shown in FIG. 5, the pilot oil is output to only one of the two pilot passages 23 and 24. Then, any one of the two pilot pressure sensors 26 and 27 detects the detected pilot pressure, and the detected pilot pressure is input to the control device 50, and the differential pressure thereof becomes the speed command signal _VCOM . Similarly, the rotational speed detected by the rotational speed sensor 44 is input to the control device 50 and becomes the speed feedback signal _VFB . The controller 50 calculates a target acceleration torque based on the speed difference between the two speed command signals _VCOM and the speed feedback signal _VFB . Then, the control device 50 controls the operations of the hydraulic motor 33 and the motor 34 so that the target acceleration torque is output. Thus, the swing body 5 can be turned at a speed corresponding to the amount of tilt of the control lever 25, that is, at a speed corresponding to the speed command signal _VCOM .

Thereafter, when the control lever 25 moves to the neutral position, the pilot pressure on the high pressure side decreases, the spool 22 of the control valve 11 moves to the neutral position M1, and the opening of the control valve 11 becomes smaller. On the other hand, the hydraulic pressure detected by the two pilot pressure sensors 26, 27 also decreases. Then, control device 50 determines that the deceleration control should be performed based on the speed difference between speed command signal _VCOM and speed feedback signal _VFB, and starts the speed reduction control. Then, the deceleration control process starts, and the process proceeds to step S1 in FIG. The flowchart of FIG. 6 is for the case where the servo is turned off when the discharge power due to the steady loss of the drive device 36 becomes larger than the charge power due to the regenerative operation of the motor 34 at the time of deceleration by the motor 34.

  In step S1 which is a regenerative braking process, the control device 50 decelerates the output shaft 35 by causing the motor 34 to perform a regenerative operation. That is, control device 50 controls the operation of drive device 36 (the operation of the switching element) to convert all of the alternating current generated by motor 34 into direct current and store all the power generated by motor 34 in capacitor 28. And the output shaft 35 is decelerated. Further, the controller 50 gives a command to the electromagnetic relief valves 15 and 16 connected to the oil paths 31 and 32 on the discharge side so that the energy regeneration by the motor 34 is efficiently performed, and opens the hydraulic motor 33 Adjust the braking force by. If the output shaft 35 decelerates, it will transfer to step S2.

  In step S2 which is a step of determining the power stop condition, it is determined whether the control device 50 satisfies the power stop condition. Here, the power stop condition is a condition that the speed of the rotating body 5 is equal to or lower than a predetermined speed (that is, the absolute value of the speed of the rotating body 5 is equal to or lower than a predetermined speed) regardless of the forward direction and the reverse direction. Further, the predetermined speed is a speed at which the steady loss energy consumed by the motor 34 and the drive unit 36 when braking the swing structure 5 becomes larger than the charging power generated by the motor 34. It is set according to the structure and various configurations connected to them. Control device 50 determines whether or not the speed of rotating body 5 is equal to or less than a predetermined speed based on the rotation speed detected by rotation speed sensor 44, and it is determined that the speed of rotating body 5 exceeds the predetermined speed. Then, the process returns to step S1 and the regeneration operation by the motor 34 is continued. On the other hand, when it is determined that the speed of the swing body 5 is equal to or less than the predetermined speed, the process proceeds to step S3.

  In step S3 which is a hydraulic braking process, the control device 50 controls the operation of the hydraulic fluid supply device 9 to operate the swing structure 5 by the hydraulic motor 33. Specifically, the control device 50 gives a command to the discharge side electromagnetic relief valves 15 and 16 to make the opening degree smaller (increase the set pressure of the electromagnetic relief valve) and set the brake pressure of the hydraulic motor 33 Make it higher. Thereby, the braking force can be applied to the output shaft 35, and the rotating body 5 can be braked even after the drive device 36 is stopped. When braking by the hydraulic motor 33 starts, the process proceeds to step S4.

  In step S4, which is a servo-off process, the control device 50 stops the supply of drive power to the drive device 36. Specifically, the control device 50 transmits a servo off command to the drive device 36, and the switching device in the drive device 36 is switched off to shut off the drive device 36 and the storage battery 28 to thereby drive the drive device 36. Stop. As a result, at the time of braking when it is not necessary to generate torque in the motor, the steady loss generated in the drive device 36 and the motor 34 can be eliminated, and although the regeneration operation by the motor 34 is carried out Power consumption can be prevented. When the drive device 36 and the storage battery 28 are disconnected, the process proceeds to step S5.

  In step S5, which is a rotating body stopping step, it is determined whether the speed of the rotating body 5 is substantially zero (equal to or less than the speed at which it can be determined that the rotating body 5 has stopped) regardless of the forward direction and the reverse direction. The control device 50 determines whether or not the speed of the swing body 5 is substantially zero based on the rotation speed detected by the rotation speed sensor 44, and determines that the speed of the swing body 5 is substantially zero. The deceleration control of the body 5 ends.

  The drive control system 1 that implements such deceleration control stops the supply of drive power to the drive unit 36 when the speed of the swing structure 5 becomes equal to or less than the predetermined speed, and thus the drive unit 36 and the motor 34 during deceleration braking. The power consumption of the storage battery 28 due to the steady loss can be prevented. Thereby, the electric power when the electric power (refer to the dotted line portion in the storage energy of FIG. 4) in the conventional case is consumed next by the steady loss is swirled next to the rotating body 5 (refer to the shaded portion in the storage energy of FIG. 5) It can be used as Therefore, the regeneration efficiency of the drive control system 1 can be further improved.

[Other Embodiments]
The drive control system 1 of the present embodiment is a system for adjusting the tilt angle of the swash plate 10a by a positive control method, but may be a system for adjusting the tilt angle of the swash plate 10a by a negative control method. Further, the hydraulic pump 10 may be a fixed displacement pump which can not adjust the inclination angle of the swash plate 10a.

  Further, in the drive control system 1 of the present embodiment, the electric oil swing motor 17 in which the hydraulic motor 33 and the motor 34 are integrally formed is used, but the hydraulic motor 33 and the motor 34 are separately configured. It may be done. Further, the motor 34 is not necessarily limited to the three-phase AC motor, and may be a DC motor. Further, the work machine to which the drive control system 1 is applied is not limited to the above-described hydraulic shovel 2 and may be applied to a hydraulic crane or the like. Moreover, although the hydraulic fluid used by the drive control system 1 of this embodiment is oil, it is not limited to oil and should just be liquid. Further, in the drive control system 1 of the present embodiment, the electric oil swing motor 17 in which the hydraulic motor 33 and the electric motor 34 are integrally formed is used, but may be configured by only the electric motor 34.

1, 1 A Drive control system 2 Excavator 5 Slewing body 9 Hydraulic oil supply device 17 Electric oil swing motor 28 Electric storage device
33 Hydraulic Motor 34 Motor 35 Output Shaft 36 Drive Unit 44 Speed Sensor 50 Control Unit

Claims (5)

A hydraulic motor that operates the structure by receiving a hydraulic fluid supply;
A hydraulic fluid supply device for supplying hydraulic fluid to the hydraulic motor;
A power storage device capable of being released and charged;
An electric motor that operates the structure in cooperation with the hydraulic motor by power supply from the power storage device, generates electric power, and regenerates the power storage device to brake the structure;
A driving device that operates by supplying driving power to drive the motor, and adjusts power supplied to the motor and regenerative power to the power storage device;
A controller configured to set a motor target torque of the motor, supply drive power to the drive device according to the motor target torque, and control an operation of the drive device ;
A speed detector for detecting the operating speed of the structure;
The controller decelerates the structure and the operation speed detected by the speed detector generates steady loss energy consumed by the motor and the driving device when the motor is braked when the structure is braked. Driving of a working machine, wherein the motor target torque is set to zero and supply of drive power to the drive device is stopped when it is determined that the power stop condition including the speed that is greater than the charge power is satisfied. Control system.   The control device acquires the storage amount of the power storage device, reduces the target torque of the motor to zero when the storage amount is less than a predetermined amount, and stops the supply of drive power to the drive device. A drive control system of a work machine according to item 1. A drive control system according to claim 1 or 2 ;
And the above structure,
The structure is a swing body,
A working machine, wherein the electric motor and the hydraulic motor are configured to rotationally drive the rotating body via a reduction gear. A motor that operates and generates power by supplying power from the storage device and generates power to regenerate the storage device and brakes the structure, and a hydraulic motor driven by the hydraulic fluid supplied from the hydraulic fluid supply device A drive control system for a working machine, in which a drive device is operated to operate the structure and a drive device operated by supply of drive power adjusts the supply power of the motor and the regenerative power of the storage device according to a target torque of the motor. Drive control method of
A setting step of setting a motor target torque of the motor;
The structure is decelerating and the operating speed of the structure is equal to or less than the speed at which the steady loss energy consumed by the motor and the drive when braking the structure is greater than the charging power generated by the motor A first determination step of determining whether a power stop condition including a certain condition is satisfied;
When it is determined to satisfy the power stop condition in the first judging step, and a stopping step of stopping the driving of the drive unit stops the power supply from said power storage device to the drive device, the drive of the work machine Drive control method of control system. In the first determination step, the storage amount of the power storage device is acquired, and when the storage amount becomes equal to or less than a predetermined amount, the motor target torque is made zero and supply of drive power to the drive device is stopped. A drive control method of a drive control system of a working machine according to claim 4 .