JP2010106511A - Slewing control device of working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operability by a method in which a change in the number of revolutions of an engine and a change in slewing characteristics caused by combined control in the case of a shovel combining hydraulic and electric systems and making slewing motion by an electric motor are set to be close to changes in the case of a full hydraulic shovel. <P>SOLUTION: A speed of a slewing motor 19 is controlled to a speed based on a slewing control input; and a limit value of the slewing torque of the slewing motor is changed in the direction of lowing the acceleration of slewing with respect to the state of a mode of decreasing an accelerator control input of increasing a hydraulic actuator control input and decreasing the amount of fuel supply in accordance with at least one of the accelerator control input, the hydraulic actuator control input and the state of the mode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a turning control device for a hydraulic / electric combined work machine that uses both a hydraulic action by a hydraulic actuator and a turning action by an electric motor.

  The background art will be described using an excavator as an example.

  As shown in FIG. 13, the excavator has an upper swing body 2 mounted on a crawler type lower traveling body 1 so as to be rotatable around a vertical axis O. The upper swing body 2 has a boom 3, an arm 4, a bucket 5, and Excavation attachment A provided with each cylinder 6, 7, 8 for booms, arms, and buckets is mounted.

  In this excavator, instead of a full hydraulic drive system in which all operations are performed by operating a hydraulic actuator with hydraulic oil from an engine driven hydraulic pump, as shown in Patent Document 1, a swing operation is performed by an electric motor (swing There has been proposed a hydraulic / electric combined system in which other operations are performed by a hydraulic actuator driven by a hydraulic pump as before. Hereinafter, an excavator that employs an all-hydraulic drive system is referred to as an all-hydraulic excavator, and an excavator that employs a combined system is referred to as a combined excavator as necessary.

  In this combined excavator, the turning operation is performed independently by the electric motor and is not affected by the engine speed or the hydraulic operation, and therefore, the movement different from that of the entire hydraulic excavator occurs in the following points.

(A) Relationship with engine speed In all hydraulic excavators, the fuel supply to the engine changes in proportion to the amount of accelerator operation, and the engine speed changes.

  In addition, when a work mode is switched between three modes, for example, a heavy work mode, a standard work mode, and a light work (beautiful operation) mode, the fuel supply amount to the engine in each hydraulic excavator depends on each mode. Changes (maximum in heavy work mode) and engine speed changes.

  In response to such changes in engine speed, the discharge amount of the hydraulic pump decreases in all hydraulic excavators and the pressure of the swing motor (hydraulic motor) also decreases, so the speed and acceleration of the swing decrease. In combination excavators, neither turning speed nor acceleration changes.

(B) At the time of compound operation At the time of compound operation that performs hydraulic operation such as raising the boom during turning, all hydraulic excavators reduce the amount of oil supplied to the turning motor (hydraulic motor) and the pressure by hydraulic operation. The speed and acceleration of the turn decrease. In contrast, the combined excavator does not change the turning speed or acceleration at all.

  For this reason, for an operator who is accustomed to the movement of such a hydraulic excavator, the combined excavator in which the turning speed and acceleration do not change in the cases (A) and (B) described above, the movement is uncomfortable, and the operability is poor in this respect There was a problem.

  Note that Patent Document 1 discloses a control that resemble the movement of a hydraulic excavator by changing the turning speed in accordance with the engine speed in response to the problem that the turning speed does not change with changes in the engine speed. Technology is disclosed.

Therefore, it is conceivable to apply this technique to control the turning electric motor so as to change the turning speed even during the combined operation.
WO 2006/004080 Publication

  However, in all hydraulic excavators, as a turning characteristic at the time of engine speed change or complex operation, the acceleration decreases due to a decrease in pressure simultaneously with a decrease in the amount of oil supplied from the pump to the turning motor, and the speed decreases. Therefore, simply controlling the speed will not give you the actual movement or sensation of “acceleration slowing down”.

  For example, as a typical example of combined operation, during combined turning / boom raising operation, the amount of oil supplied to the boom cylinder changes greatly, and the acceleration of all hydraulic excavators is severely slowed down. It will not be realized, and there will still be a sense of incongruity in the operation.

  Therefore, the present invention provides a turning control device for a work machine that can improve operability by making changes in engine speed and turning characteristics due to complex operations closer to those of all hydraulic excavators.

  The invention of claim 1 is a swing electric motor that drives a swing body to rotate, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, and a swing operation means that issues a swing command to the swing motor; Hydraulic actuator operating means for issuing an operation command to the hydraulic actuator; an accelerator for setting a fuel supply amount to the engine; a mode switching means for switching a work mode between a plurality of modes having different fuel supply amounts to the engine; A control means for controlling the swing motor, wherein the control means controls the swing motor to a speed corresponding to the operation amount of the swing operation means, and the operation amount of the accelerator, the hydraulic actuator operation means According to the operation amount and at least one of the mode states selected by the mode switching means, It is configured to change the limit value of the turning torque of the swing motor in the direction that the acceleration of the turn slows down in the mode state in which the amount of operation of the accelerator is decreased, the amount of operation of the hydraulic actuator is increased, and the fuel supply amount is decreased. It is.

  The invention of claim 2 is a turning electric motor that drives the turning body to turn, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, a turning operation means that issues a turning command to the turning motor, Hydraulic actuator operating means for issuing an operation command to the hydraulic actuator; an accelerator for setting a fuel supply amount to the engine; a mode switching means for switching a work mode between a plurality of modes having different fuel supply amounts to the engine; A control means for controlling the swing motor, wherein the control means controls the swing motor to a speed corresponding to the operation amount of the swing operation means, and the operation amount of the accelerator, the hydraulic actuator operation means According to the operation amount and at least one of the mode states selected by the mode switching means, Reduction of Kuseru operation amount, the increase in the hydraulic actuator operation amount in which the amount of fuel supply is configured to vary the turn acceleration of the turning electric motor in the direction in which the acceleration of the turning has slowed relative mode state to decrease.

  The invention according to claim 3 is a turning electric motor that drives the turning body to turn, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, and a turning operation means that issues a turning command to the turning motor; Hydraulic actuator operating means for issuing an operation command to the hydraulic actuator; an accelerator for setting a fuel supply amount to the engine; a mode switching means for switching a work mode between a plurality of modes having different fuel supply amounts to the engine; A control means for controlling the swing motor, wherein the control means controls the swing motor to a speed corresponding to the operation amount of the swing operation means, and the operation amount of the accelerator, the hydraulic actuator operation means According to the operation amount and at least one of the mode states selected by the mode switching means, It is configured to change the limit value of the swing motor power in a direction in which the acceleration of the turn slows down with respect to the mode state in which the decrease in the xel operation amount, the increase in the hydraulic actuator operation amount, and the fuel supply amount decrease. .

According to the present invention, the limit value of the turning torque of the turning motor is changed according to at least one of the accelerator operation amount, the hydraulic actuator operation amount, and the mode state (Claim 1), or the turning acceleration is changed (Billing). Item 2), or the limit value of the swing motor power is changed (Claim 3), that is,
i. Decrease in accelerator operation amount,
ii. Increase of hydraulic actuator operation amount,
iii. Since the configuration is such that the turning acceleration is slowed down in the mode state where the fuel supply amount decreases, in the case of i to iii above, the movement is very close to the movement of the entire hydraulic excavator where the speed decreases while the turning acceleration slows down. Can realize the sensation. For this reason, there is no sense of incongruity in comparison with all hydraulic excavators, and operability can be improved in this respect.

  In this case, according to the first aspect of the present invention, in the stage where the speed target value corresponding to the turning operation amount is obtained and the torque command is issued to the turning electric motor in order to perform the speed control toward the speed target value, Processing to limit is performed.

  On the other hand, in the second and third aspects of the invention, a speed target value corresponding to the turning operation amount is obtained, and acceleration limitation is performed at the stage of obtaining a speed command value for speed control toward the speed target value (claim 2). ) Or power limitation (Claim 3) is performed, but the final acceleration pattern is the same, and in both cases, the result of speed reduction accompanied by slowing of acceleration can be obtained.

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

  In the first embodiment shown in FIGS. 1 to 6, control for changing the limit value of the turning torque corresponding to claim 1 is performed, and in the second embodiment shown in FIGS. The third embodiment shown in FIGS. 10 to 12 is configured to perform the control for changing the limit value of the turning motor power corresponding to the third aspect.

1st Embodiment The whole structure of the turning control apparatus concerning 1st Embodiment is shown in FIG.

  First, the drive system will be described. The power of the engine 11 is applied to the hydraulic pump 13 and the generator motor 14 via the power distribution device 12.

  The boom pump 6 and other hydraulic actuators (collectively denoted by reference numeral 16) of FIG. 13 are connected to the hydraulic pump 13 via the control valve 15, and these are driven by the pressure oil from the hydraulic pump 13. .

  The electric power from the generator motor 14 is sent to the swing motor 19 via both the inverters 17 and 18 for the generator motor and the swing motor, and the rotational force of the swing motor 19 is transmitted to the upper swing body 2 via the swing reduction mechanism 20. The revolving unit 2 is revolved around the vertical axis O in FIG.

  A battery 21 is provided between the inverters 17 and 18, and this battery 21 is combined with the generator motor 14 and used as a power source for the swing motor 19.

  Reference numeral 22 denotes an encoder as a turning speed detecting means for detecting the rotational speed (actual speed) of the turning electric motor 19, and the turning speed detected by the encoder 22 is input to a controller 23 as a control means.

  Further, as operation equipment, a turning operation lever 24 that is a turning operation means, a hydraulic actuator operation lever (denoted as a hydraulic operation lever in FIG. 1) 25 that is a hydraulic actuator operation means, and a fuel supply amount to the engine 11 Mode switching for switching between an accelerator 26 for setting the engine and a plurality of modes (for example, a heavy work mode with the largest fuel supply amount, an intermediate standard mode, and a light work mode with the smallest fuel supply amount). A mode changeover switch 27 is provided as a means, and a detection means (not shown) for detecting the operation amount of both levers 24 and 25 (hereinafter referred to as turning operation amount and hydraulic operation amount), accelerator operation amount, and mode state is detected. Via the controller 23.

  The configuration of the controller 23 is shown in FIG.

  As a basic component, the controller 23 calculates a target turning speed from the turning operation amount based on the map of FIG. 3, and generates a speed command value generating means 28 for generating a speed command value for obtaining the target turning speed. A speed control means 29 for outputting a torque command value for performing, for example, feedback speed control (PI control) based on the actual turning speed detected by the encoder 22 and the speed command value (target turning speed); Torque control means 30 for controlling torque (current) based on a torque command value from the speed control means 29 is provided.

  Here, when the technique disclosed in Patent Document 1 is applied, for example, in the combined operation of turning and hydraulic actuator operation, the speed command value is set according to the amount of hydraulic operation as control to bring the turning movement closer to that of all hydraulic excavators. It is conceivable to perform speed feedback control based on the reduced speed command.

  On the other hand, in the first embodiment, the torque limit value generating means 31 and the torque limiting means 32 are provided as components for bringing the turning movement closer to that of the entire hydraulic excavator in the case of the above example. .

  The torque limit value generating means 31 obtains the limit value of the turning torque according to the hydraulic operation amount, the accelerator operation amount, and the mode state.

  For example, for the hydraulic operation amount, the torque limit value is decreased as the operation amount increases based on the map of FIG. 4, and for the accelerator operation amount, the torque limit value is set according to the map of FIG. 5 as the operation amount decreases. Reduce.

  As for the mode state, the torque limit value is decreased in the heavy work mode and increased in the light work mode with reference to the standard mode.

  The torque limiting unit 32 limits the torque command value from the speed control unit 29 based on the torque limit value sent from the torque limit value generating unit 31, and uses the limited value as a final torque command value for torque control. Send to means 30.

  As a result, for example, during compound operation, the turning torque is limited as shown in FIG. 6 and the turning acceleration is slowed down. The larger the hydraulic operation amount, the tighter the torque restriction (slowing down the acceleration).

  As a result, it is possible to obtain a turning characteristic very close to that of the hydraulic turning, in which the turning speed decreases while the acceleration decreases according to the hydraulic operation amount. The same applies to the accelerator operation amount and the mode state.

Second Embodiment In the second embodiment shown in FIG. 7 to FIG. 9, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

  Explaining only the differences from the first embodiment, as can be seen by comparing FIG. 2 and FIG. 7, an acceleration generating means 33 is provided instead of the torque limit value generating means 31 of the first embodiment.

  The acceleration generating means 33 reduces the acceleration of the turn with respect to the increase of the former, based on the map of FIG. 8 for the hydraulic actuator operation amount, and the map of FIG. 9 for the accelerator operation amount. Increase against the increase. In addition, the acceleration is reduced in the heavy work mode.

  The acceleration determined by the acceleration generating means 33 is sent to the speed command value generating means 28, and a speed command value obtained by adding an acceleration limit to the target speed is obtained by the means 28, and this is sent to the speed control means 29.

  As a result, as in the first embodiment, it is possible to obtain a turning characteristic very close to that of hydraulic turning, for example, the turning speed decreases while the acceleration of turning decreases with an increase in the amount of hydraulic operation during combined operation.

Third Embodiment In the third embodiment, as shown in FIG. 10, a power limit value generating means 34 is provided instead of the torque limit value generating means 31 of the first embodiment and the acceleration generating means 33 of the second embodiment. In addition, power limiting means 35 is provided instead of the torque limiting means 32 of the first embodiment.

  The power limit value generating unit 31 sets the power limit value (power is speed × torque) of the swing motor 19 based on the map of FIG. 11 for the hydraulic operation amount and the map of FIG. 12 for the accelerator operation amount, respectively. It is set so as to decrease with respect to the former increase and increase with respect to the latter increase. Also, the power limit value is lowered in the heavy work mode.

The power limiting means 35 calculates the maximum torque from the power limit value obtained by the power limit value generating means 34.
The maximum torque = power limit value / motor speed is calculated, and a torque command value is output toward the torque (current) control means 30 so that the motor power is equal to or less than the power limit value.

  Also according to the third embodiment, the result of the speed reduction accompanied by the deceleration of acceleration can be obtained as in the first and second embodiments.

It is a block diagram showing the whole turning control device composition concerning a 1st embodiment of the present invention. It is a block diagram which shows the structure of the controller in the apparatus. It is a figure which shows the relationship between the turning operation amount by the same apparatus, and target turning speed. It is a figure which shows the relationship between the hydraulic actuator operation amount and a torque limiting value. It is a figure which shows the relationship between the same accelerator operation amount and a torque limiting value. It is a figure which shows the change condition with respect to time of the turning torque and turning speed as a control result by the apparatus. It is a block diagram which shows the structure of the controller of the turning control apparatus concerning 2nd Embodiment of this invention. It is a figure which shows the relationship between the hydraulic actuator operation amount and acceleration by the same apparatus. It is a figure which shows the relationship between the accelerator operation amount and acceleration. It is a block diagram which shows the structure of the controller of the turning control apparatus concerning 3rd Embodiment of this invention. It is a figure which shows the relationship between the hydraulic actuator operation amount by the same apparatus, and a power limiting value. It is a figure which shows the relationship between the accelerator operation amount and a power limit value. 1 is a schematic side view of an excavator to which the present invention is applied.

Explanation of symbols

2 Revolving body 11 Engine 13 Hydraulic pump 14 Generator motor 19 Motor 23 Controller (control means)
24 Turning control lever (turning operation means)
25 Hydraulic actuator operating lever (hydraulic actuator operating means)
26 Accelerator 27 Mode selector switch (mode selector)
28 Speed command value generation means 29 Speed control means 30 Torque (current) control means 31 Torque limit value generation means 32 Torque limit means 33 Acceleration generation means 34 Power limit value generation means 35 Power limit means

Claims (3)

  A swing electric motor that drives the swing body to rotate, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, a swing operation means that issues a swing command to the swing motor, and an operation command to the hydraulic actuator. A hydraulic actuator operating means for outputting, an accelerator for setting a fuel supply amount to the engine, a mode switching means for switching a work mode among a plurality of modes having different fuel supply amounts to the engine, and a control means for controlling the swing motor And the control means controls the swing motor to a speed corresponding to the operation amount of the turning operation means, and the operation amount of the accelerator, the operation amount of the hydraulic actuator operation means, and the mode switching means The amount of accelerator operation is reduced according to at least one of the mode states selected by The operation is characterized in that the limit value of the turning torque of the swing motor is changed in a direction in which the acceleration of the turn slows with respect to the mode state in which the hydraulic actuator operation amount increases and the fuel supply amount decreases. Machine turning control device.   A swing electric motor that drives the swing body to rotate, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, a swing operation means that issues a swing command to the swing motor, and an operation command to the hydraulic actuator. A hydraulic actuator operating means for outputting, an accelerator for setting a fuel supply amount to the engine, a mode switching means for switching a work mode among a plurality of modes having different fuel supply amounts to the engine, and a control means for controlling the swing motor And the control means controls the swing motor to a speed corresponding to the operation amount of the turning operation means, and the operation amount of the accelerator, the operation amount of the hydraulic actuator operation means, and the mode switching means The amount of accelerator operation is reduced according to at least one of the mode states selected by The turning control of the working machine is characterized in that the turning acceleration of the turning motor is changed in a direction in which the turning acceleration is slowed down with respect to the mode state in which the operation amount of the hydraulic actuator increases and the fuel supply amount decreases. apparatus.   A swing electric motor that drives the swing body to rotate, a hydraulic actuator that is driven by pressure oil from a hydraulic pump that uses an engine as a power source, a swing operation means that issues a swing command to the swing motor, and an operation command to the hydraulic actuator. A hydraulic actuator operating means for outputting, an accelerator for setting a fuel supply amount to the engine, a mode switching means for switching a work mode among a plurality of modes having different fuel supply amounts to the engine, and a control means for controlling the swing motor And the control means controls the swing motor to a speed corresponding to the operation amount of the turning operation means, and the operation amount of the accelerator, the operation amount of the hydraulic actuator operation means, and the mode switching means The amount of accelerator operation is reduced according to at least one of the mode states selected by The working machine is configured to change the limit value of the swing motor power in a direction in which the acceleration of the swing is slowed with respect to the mode state in which the hydraulic actuator operation amount increases and the fuel supply amount decreases. Swivel control device.

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