JP4557187B2 - Electric motor control device - Google Patents

Description

  The present invention relates to an electric motor control device that controls an electric motor that operates an inertial body based on an operation of an operation end.

  A hydraulic drive device using a hydraulic pump or a hydraulic motor is used as a drive device for operating an inertial body having a large inertial mass such as a construction machine or the like such as a swing operation of a hydraulic excavator or a hydraulic crane or a traveling operation of a wheel loader. Many were adopted. In recent years, an electric drive system that controls the operation of an inertial body with an electric motor with a small energy loss is being adopted instead of a hydraulic drive system that uses a hydraulic drive apparatus with a large energy loss in order to reduce the hydraulic energy with a control valve. . The electric drive system has an advantage that when the inertial body is decelerated, the braking energy can be regenerated by using the electric motor as a generator.

  However, the hydraulic drive method using the conventional hydraulic drive device is operated so that the operability of the operator controlling the operation of the inertial body by operating the operation ends such as the lever and the pedal is adapted to the human sense of operation. In contrast to the design that is easy, the electric drive system using an electric motor cannot realize the operability and operation feeling like the hydraulic drive system, and there is a problem that it is difficult for the operator to operate.

  In other words, in the hydraulic drive system, the opening area of the bleed-off control throttle and meter-out control throttle of the spool valve is controlled by the operation of the operation end, so that the amount of operation at the operation end and the flow rate through each control throttle The differential pressure is controlled. The output torque of the hydraulic motor is controlled by the differential pressure, and the inertial body is smoothly accelerated, decelerated, and stopped. On the other hand, in the case of the electric drive system, if the rotational speed of the motor is controlled, the speed control is performed with the output torque as the maximum value, so the acceleration and deceleration of the inertial body becomes steep and smooth operation like the hydraulic drive system There is a problem that the operational feeling of the operator is far from the hydraulic drive system.

  In order to solve these problems, research and development to move the operability and operation feeling when operating an inertial body such as a construction machine with an electric drive system to those of a hydraulic drive system has been promoted. Some means have been proposed for controlling the output torque of the electric motor based on the operation of the operation end so that the pressure is close to that of the hydraulic drive system (see, for example, Patent Document 1-2).

  In the construction machine drive device described in Patent Document 1, the first target torque is calculated based on a predetermined functional relationship with respect to the operation amount of the operation end, and the operation amount of the operation end is determined in advance. Calculating a target speed of the electric motor based on a predetermined functional relationship, calculating a second target torque based on a predetermined functional relationship with respect to a speed deviation between the target speed of the electric motor and the actual speed; Of these first and second target torques, the output torque of the motor is controlled with the target torque having the smaller absolute value as the target value. That is, in Patent Document 1, for example, during an acceleration operation in which the speed deviation between the target speed and the actual speed of the electric motor is large, the first target torque (<first order) calculated based on the operation amount of the operator is used. 2), the second target torque (<first target torque) calculated based on the speed deviation is the target value when the speed of the motor increases and the speed deviation decreases. By selecting the target torque having the smaller absolute value of the first target torque and the second target torque as the target value, the torque control characteristic according to the operation amount of the operator can be obtained in the acceleration transition period or the like. I am doing so. Furthermore, the allowable maximum torque calculated based on a predetermined functional relationship with respect to the actual speed of the electric motor is set as the third target torque, and the third target torque is included in the first and second target torques. It has also been proposed to use the target torque having the smallest absolute value as the target torque to prevent overload of the motor.

  In the swing drive device for a construction machine described in Patent Document 2, the starting torque in the case where the swing drive system is a hydraulic pump-directional control valve-hydraulic motor is simulated in accordance with the input amount of the lever device that gives the swing drive command. And a control means for calculating the braking torque and setting the difference between the starting torque and the braking torque as the driving torque of the electric motor that drives the turning. Further, the input amount of the lever device and the actual rotational speed of the electric motor are used as the input amount, and the lever input amount-torque table and the actual rotational speed-torque table are provided, and the minimum torque value obtained from each table is the starting torque. It is characterized by doing. By configuring as described above, the same operation characteristics as those of the hydraulic drive system can be obtained even in the swing drive device using the electric motor, and the flow of the swing body and the sudden stop due to the operation of the operator can be prevented, thereby improving safety. You can do that. Furthermore, an output control dial that can change the output is provided, and by reducing the value of the starting torque in proportion to the command value of the output control dial, the operator can change the command torque and obtain the desired turning operation. ing.

JP 2003-033063 A JP 2007-205032 A

  Patent Document 1 describes an output of an electric motor using a target torque having a smaller absolute value among a first target torque based on an operation amount and a second target torque based on a speed deviation of the electric motor as a target value. As shown below, the torque control is essentially different from the control method using a control valve in the case of hydraulic drive. In the control by the hydraulically driven control valve, the control valve spool opening area (the size of the control throttle) is controlled by the operation of the operation end, and the actuator driving pressure is obtained by applying a differential pressure to the flow rate flowing through the spool opening. Control the braking pressure of the actuator. That is, the actuator driving pressure and braking pressure are determined by the combination of two independent variables of the spool opening area and the flow rate determined by the manipulated variable, and the lower one of the pressures determined by one of the variables is selected. I don't mean. Therefore, the technique of Patent Document 1 cannot realize the same control as that of the hydraulic drive system, and has a problem that its operability and operation feeling are different from those of the hydraulic drive system.

  Patent Document 2 describes a case where a swing drive system is a hydraulic pump-direction control valve-hydraulic motor in a swing drive device for a construction machine in accordance with an input amount of a lever device that gives a swing drive command. Control means that calculates the starting torque and braking torque of the motor and uses the difference between the starting torque and the braking torque as the driving torque of the electric motor that drives the turning, so that the same control characteristics as the hydraulic driving are realized by the electric motor driving. be able to. However, in spite of the fact that it is replaced with motor-driven control through the characteristics of hydraulically driven equipment, it is not possible to design a free control due to the influence of the structure of hydraulic equipment such as control valves, or For this reason, there is a problem that the calculation for this is complicated.

  Further, the input amount of the lever device and the actual rotational speed of the electric motor are used as the input amount, and the lever input amount-torque table and the actual rotational speed-torque table are provided, and the minimum torque value obtained from each table is the starting torque. However, for the same reason as the problem of Patent Document 1, the same control as the hydraulic drive method cannot be realized, and the operability and operation feeling thereof are different from those of the hydraulic drive method. There is a problem.

  Furthermore, if the value of the starting torque is reduced in proportion to the command value of the output control dial, the maximum torque necessary for the turning drive device is not generated, which is a problem. For example, when working on an inclined ground, the force of turning in the upward direction of the inclined surface becomes weak, and the working ability is reduced.

  Therefore, the problem of the present invention is that control similar to that of a hydraulic drive system can be obtained by control based on a simple algorithm, and the speed of the motor is set to a speed limit value equal to or less than the maximum value of the apparatus. In such a case, it is an object of the present invention to provide an electric motor control device that can output a maximum torque and perform smooth torque control.

  In order to solve the above-described problems, the present invention provides an operation detection means for controlling the rotational motion of an electric motor that operates an inertial body by operating an operation end having a variable operation amount, and detecting the operation amount, and the electric motor. In the motor control device comprising a rotation detection means for detecting the rotation speed of the motor, and an electric motor control means for controlling the electric motor based on the detected values of the operation detection means and the rotation detection means, the output torque of the electric motor is The output torque and the rotation speed are determined according to the operation amount and the rotation speed, the output torque and the rotation speed are limited to a maximum torque or less and a maximum rotation speed or less as a control device of the electric motor, and the rotation speed is different from the maximum rotation speed. A rotation speed limit value setting means for setting the rotation speed limit value is set, and when the value of the rotation speed limit value setting means is set to a rotation speed limit value equal to or less than the maximum rotation speed, The value of the output torque operation amount and determined in response to said rotational speed, to use a construction where and controlling in accordance with the set ratio of the rotational speed limit value and the maximum rotational speed.

  That is, in an electric motor control device including an operation detection unit that detects an operation amount of an operation end and an electric motor control unit that controls the electric motor based on each detection value of a rotation detection unit that detects the rotation speed of the electric motor. By determining the output torque according to the operation amount of the operation end and the rotation speed of the electric motor, it becomes possible to control the output torque of the electric motor so as to match the operation amount of the operation end by the operator and the rotation speed of the electric motor. Even when the inertial body operates smoothly like a hydraulic drive system and the rotation speed is set to a rotation speed limit value that is equal to or less than the maximum rotation speed as the motor control device by the rotation speed limit value setting means, The output torque value of the motor determined according to the operation amount of the motor and the rotation speed of the motor is controlled according to the ratio between the set rotation speed limit value and the maximum rotation speed. More, even if the limit of the rotational speed and the maximum possible torque output of the motor controller, and can smooth torque control according to the rotation speed of the lever operation amount and the electric motor.

  In addition to the operation amount, the operation end makes the operation direction variable in both plus and minus directions, rotates the electric motor in both plus and minus directions, and the operation detecting means detects the operation amount and the operation direction. The rotation detection means detects the rotation speed and the plus / minus rotation direction, and the output torque is composed of a power running torque for driving the inertial body by the motor and a regenerative torque for driving the motor by the inertial body. By adopting a configuration in which the absolute value of the power running torque increases as the absolute value of the operation amount increases and decreases as the absolute value of the rotational speed increases, As well as excavators and cranes that rotate the electric motor in one direction by the operation of the pedal as the operation end It can be applied to the one that rotates the motor in both plus and minus directions by operating the lever as the operation end, such as turning control, and has the same control characteristics as the bleed-off pressure control in the hydraulic drive system. The operation speed can be easily controlled by the operator.

  That is, in the hydraulic drive apparatus that drives the hydraulic motor 53 with the hydraulic pump 52 by operating the spool valve 51 as shown in FIG. 7, when the operation amount at the operation end increases as shown in FIG. 51, the opening area of the bleed-off control throttle 51a is reduced, the bleed-off pressure P0 is increased, the driving torque of the hydraulic motor 53 is increased, and the bleed-off flow rate is decreased as the rotational speed of the hydraulic motor 53 is increased. Even if the opening area of the bleed-off control throttle 51a is constant with the same operation amount, the bleed-off pressure P0 is lowered and the driving torque is controlled to be reduced. Therefore, when the rotational speed of the hydraulic motor 53 increases, the driving torque gradually decreases, and the acceleration of the inertial body disappears at a value commensurate with the driving resistance due to friction of the driving system or pressure loss of the hydraulic piping system or the spool valve 51, and the operator can The operation speed is controlled as follows. Therefore, the control characteristics similar to the control of the bleed-off pressure P0 of such a hydraulic drive system can be provided by the above feature.

  The meter-in control throttle 51b of the spool valve 51 shown in FIG. 6 is used to control the meter-in pressure P1 of the hydraulic motor 53 or to drive the hydraulic motor 53 when another actuator is operated by the same hydraulic pump 52. This is to add resistance to the pressure, and the basic control characteristic is to control the driving pressure, that is, the driving torque by controlling the bleed-off pressure P0.

  By adopting a configuration in which the absolute value of the regenerative torque increases as the absolute value of the manipulated variable decreases and decreases as the absolute value of the rotational speed decreases, the meter-out pressure in the hydraulic drive system is adopted. Control characteristics similar to those of the above control can be provided, so that the operator can easily control the target operation speed.

  That is, in the hydraulic drive apparatus as shown in FIG. 7, as shown in FIG. 9, the meter-out control throttle 51c of the spool valve 51 starts to open when the operation amount at the operation end becomes a certain value from zero. As the value increases, the opening area increases. When the operation amount is returned to decrease in this state, the meter-out pressure P2 increases, and even with the same operation amount, when the rotation speed of the hydraulic motor 53 decreases, the flow rate flowing through the meter-out control throttle 51c decreases, and the meter-out pressure P2 Is controlled to be low. Therefore, when the operation amount at the operation end is returned from a certain rotational speed of the hydraulic motor 53, the braking torque is large when the rotational speed is large, and the braking torque is decreased as the rotational speed is decreased. The inertial body decelerates at a value commensurate with the drive torque, and the operation speed is controlled by the operator. Therefore, by incorporating the above algorithm, it is possible to provide the same control characteristics as the control of the meter-out pressure P2 of such a hydraulic drive system.

  By adopting a configuration in which the output torque determined according to the operation amount of the operation end and the rotation speed of the electric motor is uniquely determined by the operation amount of the operation end and the rotation speed of the electric motor. The same control characteristics as the combination of bleed-off control and meter-out control are given to a single spool of a hydraulically driven control valve to achieve good operability equivalent to that of a hydraulically driven system. The feature is that the algorithm becomes very simple.

  The inertial body that operates with the electric motor may be an inertial body that performs a turning operation of a construction machine or a traveling operation of a traveling vehicle.

  The motor control device of the present invention comprises operation detection means for detecting the operation amount of the operation end, and motor control means for controlling the motor based on each detection value of the rotation detection means for detecting the rotation speed of the motor, By controlling the output torque of the motor according to the operation amount of the operation end and the rotation speed of the motor, the output torque of the motor can be controlled to match the operation amount of the operation end by the operator and the rotation speed of the motor. Even when the inertial body operates smoothly like a hydraulic drive system and the rotation speed is set to a rotation speed limit value that is less than or equal to the maximum rotation speed as the motor control device by the rotation speed limit value setting means. By controlling the output torque value of the motor determined according to the operation amount of the operating end and the rotation speed of the motor according to the ratio between the set rotation speed limit value and the maximum rotation speed Performing a rotational speed limit can output maximum torque as the motor control device, and can smooth torque control according to the rotation speed of the lever operation amount and the electric motor.

  In the case where the operation end is variable in both plus and minus directions in addition to the operation amount, and the electric motor is rotated in both plus and minus directions, the operation detecting means is operated in the plus or minus operation amount of the operation end. The rotation detection means detects the rotation speed of the motor and the plus / minus rotation direction, and the motor is driven by the inertial body and the power running torque that drives the inertial body by the motor. Incorporating a calculation algorithm that includes a regenerative torque to be driven, and that the absolute value of the power running torque increases as the absolute value of the operation amount of the operating end increases and decreases as the absolute value of the rotational speed of the electric motor increases. By rotating the motor in one direction by operating the pedal as the operating end It can be applied not only to those that rotate, but also to those that rotate the motor in both positive and negative directions by operating the lever as the operation end, such as excavator and crane turning control, and the bleed-off pressure in the hydraulic drive system Control characteristics similar to those of the control can be provided so that the operator can easily control the target operation speed.

  Incorporating a calculation algorithm into the calculation algorithm such that the absolute value of the regenerative torque increases when the absolute value of the operation amount at the operating end decreases and decreases when the absolute value of the rotation speed of the motor decreases. The control characteristic similar to the control of the meter-out pressure in the system can be provided so that the operator can easily control to the target operation speed.

  The output torque determined according to the operation amount of the operation end and the rotation speed of the electric motor is uniquely determined by the operation amount of the operation end and the rotation speed of the electric motor. By providing the spool with the same control characteristics as a combination of bleed-off control and meter-out control, it is possible to realize good operability equivalent to that of the hydraulic drive system.

  By using the motor control device as described above as a motor control device that drives an inertial body of a traveling vehicle that performs a turning operation or a traveling operation of a construction machine, the device has control characteristics similar to those of a hydraulic drive system. The device can be very easy to operate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a hydraulic excavator incorporating an electric motor control device according to the present invention. The hydraulic excavator includes a crawler type lower traveling body 20, an upper revolving body 30 as an inertial body that swings left and right on the lower traveling body 20, and an excavation attachment 40 attached to a front portion of the revolving body 30. It consists of. The lower traveling body 20 travels by the left and right crawlers 23 being individually driven by the traveling hydraulic motor 21 and the speed reducer 22. The excavation attachment 40 includes a boom 41, an arm 42, and a bucket 43, and a boom cylinder 41a, an arm cylinder 42a, and a bucket cylinder 43a for operating them.

  The revolving body 30 is equipped with an engine 31, a hydraulic pump 32 and a generator 33 driven by the engine 31, a power storage device 34 such as a battery and a capacitor, and an electric motor 1 and a speed reducer 35 that rotate the revolving body 30. Has been. The oil discharged from the hydraulic pump 32 is supplied to the traveling hydraulic motor 21, the boom 41, the arm 42, and the cylinders 41 a, 43 a of the bucket 43 via control valves. Further, as shown in FIG. 2, the electric power of the generator 33 is stored in the power storage device 34 with the voltage and current controlled by the converter 36 and supplied to the electric motor 1 via the inverter 4 described later. The electric motor 1 is a permanent magnet type motor having a permanent magnet as a rotor, and the electric motor control device according to the present invention controls the electric motor 1 to rotate the revolving body 30.

  FIG. 2 is a block diagram showing the configuration of the control device of the electric motor 1. This control device includes an operation detection means 2a for detecting an operation amount X in both plus and minus directions of the operation lever 2 as an operation end, a rotation speed limit value setting means 5 for setting a rotation speed limit value Y of the electric motor, and both directions. From the rotation detection means 1a for detecting the plus / minus rotation speed N of the rotating electric motor 1, the detected operation amount X of the operation lever 2, the rotation speed limit value Y, and the rotation speed N of the electric motor 1, the electric motor 1 The controller 3 calculates the output torque T of the motor 1 with respect to the power supplied from the generator 33 or the power storage device 34 and the controller 3 that calculates the direction and magnitude of the target torque To to be borne. And an inverter 4 as motor control means for controlling the direction and magnitude of the target torque To.

  The controller 3 is provided with a memory 3a, and an arithmetic algorithm 3b for dividing the target torque To into the drive torque Ta and the driven torque Tb to express the control characteristics of the hydraulic drive system is previously stored in the memory 3a. It is remembered. The target torque To is calculated as the sum of the driving torque Ta and the driven torque Tb. When the calculated target torque To is output in the same direction as the operation direction of the operation lever 2, it becomes a power running torque, and the operation direction If the output is in the opposite direction, the regenerative torque is generated. The memory 3a stores the maximum torque and the maximum rotation speed as the motor control device. The inverter 4 includes a signal conversion circuit 4a and a current control circuit 4b. The signal conversion circuit 4a converts the target torque To input from the controller 3 into a target current Io, and the current control circuit 4b outputs an output current I to the motor 1. Is controlled to be the target current Io.

  FIG. 3 shows a basic map for calculating the target torque To by the calculation algorithm 3b. In this basic map, the horizontal axis is the plus / minus operation amount X of the control lever 2, the vertical axis is the target torque To, and these relationships are represented by a characteristic curve with the plus / minus rotational speed N of the motor 1 as a parameter. In the first quadrant and the third quadrant in which the operation amount X and the target torque To have the same sign, the target torque To is the power running torque, and the second quadrant and the second quadrant in which the operation amount X and the target torque To have different signs. In the four quadrants, the target torque To is the regenerative torque. That is, in the first quadrant, the right turning power running, in the second quadrant, the left turning regeneration, in the third quadrant, the left turning power running, and in the fourth quadrant, the right turning regeneration. In the graph of FIG. 3, in order to make the map easy to see, each characteristic curve is displayed only when N = 0, 1/2, 1 (maximum speed) where the rotation speed N of the parameter is a dimensionless number. Yes.

  In the first quadrant and the third quadrant of the basic map, the absolute value of the target torque To, which is the power running torque, increases as the absolute value of the operation amount X of the operation lever 2 increases, and even if the operation amount X is constant. When the absolute value of the rotational speed N of the electric motor 1 is increased, the calculation is performed so that the absolute value of the rotational speed N decreases, and the same control characteristics as the control of the bleed-off pressure in the hydraulic drive system can be obtained. Further, in the second quadrant and the fourth quadrant of the basic map, the absolute value of the target torque To that is the regenerative torque increases as the absolute value of the manipulated variable X decreases, and even if the manipulated variable X is constant, the rotational speed When the absolute value of N is decreased, the calculation is performed so as to decrease, and control characteristics similar to those of the meter-out pressure control in the hydraulic drive system can be obtained.

  Further, in the basic map shown in FIG. 3, the power running torque is zero and the regenerative torque when the operation amount X is in a neutral range including zero and when the operation direction of the operation lever 2 and the rotation direction of the motor 1 are opposite. Is set to the maximum value Tmax. Therefore, for example, when the rotational speed N is 1/2 (Q1 point) in the fourth quadrant, the operation amount X of the operation lever 2 is changed from X1 to -X2, as indicated by an arrow in the figure. When operating in the direction opposite to the rotational direction, the regenerative torque is output at Tmax until the rotational speed N becomes zero, the right turn is decelerated, and when the rotational speed N becomes zero, the manipulated variable X in the third quadrant The power running torque corresponding to the rotational speed N = 0 (Q2 point) when the power is set to −X2 is output, and acceleration is started so as to turn the revolving body 30 to the left. In this embodiment, the absolute value of the power running torque is also set to the same maximum value Tmax as the regenerative torque.

  FIG. 4 represents a basic map for calculating the target torque To by the calculation algorithm 3b in a different view from FIG. That is, this basic map is a characteristic curve in which the horizontal axis is the plus / minus rotational speed N of the electric motor 1, the vertical axis is the target torque To, and the relationship is expressed using the operation amount X of the operation lever 2 as a parameter. Since the target torque To is uniquely determined by the operation amount X at the operating end and the absolute value N of the rotational speed of the electric motor, a predetermined relational expression expressed as To = f (X, N) is used, with N as a parameter. As shown in FIG. 4, or with X as a parameter, it can be expressed as shown in FIG. FIG. 4 shows only the first quadrant and the fourth quadrant from the first quadrant to the fourth quadrant. In the first quadrant, right-turning power running is performed, and in the fourth quadrant, right-turning regeneration is performed. The parameter manipulated variable X shows the range between 0 and the maximum manipulated variable only in stages from 1 to 5. The maximum value of the target torque is Tmax as an absolute value, and the maximum value of the rotation speed is Nmax as an absolute value. In power running, the maximum value of power is limited by the motor output, and the maximum torque is not output at the maximum speed. In the first quadrant, the absolute value of the target torque To as the power running torque increases as the absolute value of the operation amount X of the operation lever 2 increases, and even if the operation amount X is constant, the rotational speed N of the electric motor 1 is constant. The absolute value increases and decreases. In the fourth quadrant, the absolute value of the target torque To, which is the regenerative torque, increases as the absolute value of the manipulated variable X decreases, and decreases as the absolute value of the rotational speed N decreases even if the manipulated variable X is constant. ing.

  FIG. 5 shows the ratio between the set rotational speed limit value Y and the maximum rotational speed Nmax when the value of the rotational speed limit value setting means is set to a rotational speed limit value equal to or less than the maximum speed: Y / Nmax (= It represents that the magnitude of the target torque To changes according to α). The characteristic curve when the manipulated variable X in FIG. 4 is 0, 1, 2, 3, 4, 5, and maximum changes as the graph is contracted in the N-axis direction as shown in FIG. By shifting the characteristic curve in a direction in which the target torque To decreases in accordance with the rotational speed ratio α, the reduction ratio of the target torque To due to the increase in the rotational speed N increases even with the same lever operation amount X, and the lever of the operator Smooth torque control is possible by operation. Further, the maximum torque of the motor control device can be output, and there is no adverse effect caused by limiting the motor speed. 5 may be stored in the memory 3a according to the speed ratio α, or a target torque calculation formula including the rotational speed ratio α may be created and stored in the memory 3a. A map or calculation formula to be used for calculation is selected according to the rotational speed limit value Y. In FIG. 4, the maximum value of the motor output is limited by power running. However, since the motor output is not reached in FIG. 5, the maximum value of the motor output is not limited.

  FIG. 6 shows the first and fourth quadrants that turn right in FIG. 3 by disassembling the target torque To into a driving torque Ta indicated by a solid line and a driven torque Tb indicated by a dotted line. . The driving torque Ta corresponds to the torque due to the meter-in pressure of the hydraulic motor, and the driven torque Tb corresponds to the torque due to the meter-out pressure of the hydraulic motor. The absolute value of the driving torque Ta in the first quadrant is calculated so as to increase as the absolute value of the operation amount X increases, and to decrease as the absolute value of the rotational speed N increases even if the operation amount X is constant, A maximum value Tamax is set. In addition, the absolute value of the driven torque Tb in the fourth quadrant increases as the absolute value of the operation amount X decreases, and decreases as the absolute value of the rotational speed N decreases even if the operation amount X is constant. The maximum value Tbmax is set in the neutral range where the calculated operation amount X includes zero and the third quadrant where the operation direction of the operation lever 2 and the rotation direction of the electric motor 1 are opposite to each other. The target torque To shown in the first quadrant and the fourth quadrant of FIG. 3 is obtained as the sum of the drive torque Ta and the driven torque Tb calculated in this way. Although illustration is omitted, the target torque To in the second quadrant and the third quadrant of FIG. 3 that turns left is also obtained as the sum of the drive torque Ta and the driven torque Tb calculated in the same manner.

  In the above-described embodiment, the generator and the power storage device are used as power sources to control the electric motor that swings the upper swing body of the excavator left and right. However, the motor control device according to the present invention includes, for example, a wheel The present invention can also be applied to an apparatus that controls an electric motor having characteristics in which the rotational speed and output torque of the electric motor are different depending on the direction of movement of the inertial body, such as an apparatus that travels a traveling vehicle such as a loader or an automobile. Also, the power source of the motor is not limited to the generator or the power storage device. For example, when controlling the motor that operates the inertial body of the device placed in a factory or the like, the power supplied from the power company or the like Can be used as a power source.

  Furthermore, in the above-described embodiment, the calculation algorithm of the driving torque and the driven torque is stored in the controller as a characteristic curve expressed by a map. However, the calculation algorithm of the driving torque and the driven torque is determined by the operation of the operation end. You may make it memorize | store as numerical formula which uses quantity and the rotational speed of an electric motor as a parameter.

  Furthermore, in the above-described embodiment, the rotation speed limit value setting means of the electric motor has been described as an independent means. However, it is configured to function in conjunction with switching of an operation pattern or an operation pattern of a machine on which the electric motor control device is mounted. Also good.

The side view which shows the hydraulic excavator incorporating the control apparatus of the electric motor which concerns on this invention The block diagram which shows the structure of the control apparatus of the electric motor integrated in the hydraulic shovel of FIG. Graph showing the basic map of the algorithm of FIG. FIG. 3 is a graph different from FIG. 3 showing the basic map of the arithmetic algorithm of FIG. A graph showing the calculation algorithm map when the rotation speed limit value is set FIG. 3 is a graph showing the target torque in the first quadrant and the fourth quadrant of the graph of FIG. 3 broken down into drive torque and driven torque. Hydraulic circuit diagram of conventional hydraulic drive The graph which shows the control characteristic of the bleed-off pressure in the hydraulic drive unit of FIG. The graph which shows the control characteristic of the meter out pressure in the hydraulic drive unit of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric motor 1a Rotation detection means 2 Operation lever 2a Operation detection means 3 Controller 3a Memory 3b Arithmetic algorithm 4 Inverter 4a Signal conversion circuit 4b Current control circuit 5 Rotational speed limit value setting means 20 Traveling body 21 Traveling hydraulic motor 22 Decelerator 30 Rotating body 31 Engine 32 Hydraulic pump 33 Generator 34 Power storage device 35 Reducer 36 Converter 40 Excavation attachment 41 Boom 41a Boom cylinder 42 Arm 42a Arm cylinder 43 Bucket 43a Bucket cylinder

Claims (5)

  An operation detecting means for controlling the rotational movement of the electric motor that operates the inertial body by an operation of an operation end with a variable operation amount, detecting the operation amount, a rotation detecting means for detecting the rotation speed of the electric motor, and In an electric motor control device including electric motor control means for controlling the electric motor based on each detection value of the operation detection means and the rotation detection means, an output torque of the electric motor is determined according to the operation amount and the rotation speed, Rotation speed limit value setting means for limiting the output torque and the rotation speed to a maximum torque or less and a maximum rotation speed or less as a control device of the electric motor, and setting the rotation speed to a limit value different from the maximum rotation speed Provided, when the value of the rotational speed limit value setting means is set to a rotational speed limit value equal to or less than the maximum rotational speed, before being determined according to the operation amount and the rotational speed The value of the output torque, a motor control apparatus, characterized by controlled according to the ratio of the set the rotation speed limit value the maximum rotational speed.   In addition to the operation amount, the operation end makes the operation direction variable in both plus and minus directions, rotates the electric motor in both plus and minus directions, and the operation detecting means detects the operation amount and the operation direction. The rotation detection means detects the rotation speed and the plus / minus rotation direction, and the output torque is composed of a power running torque for driving the inertial body by the motor and a regenerative torque for driving the motor by the inertial body. 2. The motor control device according to claim 1, wherein the absolute value of the power running torque increases as the absolute value of the operation amount increases, and decreases as the absolute value of the rotation speed increases.   The motor control device according to claim 2, wherein the absolute value of the regenerative torque increases when the absolute value of the manipulated variable decreases and decreases when the absolute value of the rotational speed decreases.   4. The motor control device according to claim 1, wherein the output torque determined according to the operation amount and the rotation speed is uniquely determined by the operation amount and the rotation speed. 5.   5. The motor control device according to claim 1, wherein the inertial body that operates with the electric motor is an inertial body that performs a turning operation of a construction machine or a traveling operation of a traveling vehicle.

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