WO2016152650A1

WO2016152650A1 - Slewing device

Info

Publication number: WO2016152650A1
Application number: PCT/JP2016/058130
Authority: WO
Inventors: 弘明長井
Original assignee: 住友重機械工業株式会社
Priority date: 2015-03-24
Filing date: 2016-03-15
Publication date: 2016-09-29
Also published as: CN107251409A; CN107251409B; JP6487529B2; JPWO2016152650A1

Abstract

A speed reducer 504 transmits rotation of a slewing motor 502 to a slewing body 4. A slewing motor driver 506 drives the slewing motor 502. A controller 520 (i) controls the slewing motor driver 506 in accordance with an operation command value S1 during a non-idle period T_A during which the slewing body 4 slews when the slewing motor 502 is rotated. In addition, the controller 520 (ii) controls the slewing motor driver 506 during an idle period T_B, during which the slewing body 4 does not slew even when the slewing motor 502 is rotated, such that the slewing motor 502 rotates at a high speed until just before the non-idle period T_A and the rotation speed or the torque thereof drops when the non-idle period T_A is reached.

Description

Swivel device

The present invention relates to a turning device.

Recent construction machines such as power shovels and cranes are equipped with a turning device that turns the upper turning body. The turning device includes a turning motor for driving the turning body and a power transmission mechanism for transmitting the output of the turning motor to the turning body, and a hydraulic motor or an electric motor (electric motor) is used for the turning motor. In general, a reduction gear is used.

The rotation angle or rotation speed of the swing body is ideally determined uniquely by the rotation angle and rotation speed of the swing motor and the reduction gear ratio of the speed reducer. For this reason, it is rare to use a rotation angle sensor that directly acquires rotation information (rotation angle, rotation speed, rotation angular velocity, etc.) of the revolving body as a means for measuring the angle of the revolving body in an excavator. In general, an indirect measurement method is employed in which an angle sensor is provided, and the angle of the turning body is calculated by using the output value of the angle sensor of the turning motor and the reduction ratio.

This indirect swivel angle measurement method has the merit that a sensor that directly measures the swivel body angle is not necessary, but the angle transmission error and backlash of the speed reducer cause errors, which makes it possible to measure the swivel angle. There is a demerit that the accuracy of. Furthermore, when the backlash reverses the rotation direction of the motor, a section (dead zone) in which the rotation of the swing motor is not transmitted to the swing body is generated. Will collide with the gear on the revolving unit in a stopped state, causing uncomfortable vibrations in the revolving unit.

In the excavator in which a hydraulic motor is used as the swing motor, the influence of backlash was practically negligible due to the small reduction ratio due to the low response and low rotation and high torque of the hydraulic motor.

On the other hand, in a turning device used for a hybrid excavator, an AC electric motor (electric motor) is used as a turning motor. In this case, the steep rise in the rotational speed due to the high response of the electric motor and the increase in the backlash amount in terms of the motor shaft associated with the use of the high reduction ratio reducer to cope with high rotation and low torque. The effects of backlash can become a problem.

Among the effects of backlash, the vibration that occurs when switching the rotation direction of the swing motor is a major problem. As a technique for reducing this, for example, Patent Document 1 discloses a technique for limiting the rotational speed and torque of the swing motor in the backlash section.

International Publication No. 06/033401 Pamphlet

The technique described in Patent Document 1 has the effect of reducing the energy transmitted from the swing motor to the swing body during escape of the backlash section and reducing the collision. However, since the rotation speed of the swing motor is reduced in the backlash section, the time from the start or rotation direction switching of the swing motor to the escape of the backlash section is increased, and there is a demerit that the operation performance of the swing body is lowered. Such a problem may also occur when a hydraulic motor is used as the swing motor.

The present invention has been made in view of such problems, and one of the exemplary purposes of an aspect thereof is to provide a turning device capable of suppressing vibration while maintaining the motion performance of the turning body.

An aspect of the present invention relates to a traveling mechanism and a swing device that is mounted on an excavator including an upper swing body that is rotatably mounted on the travel mechanism, and that swings the upper swing body based on an operation command value. The swing device includes a swing motor, a speed reducer that transmits the rotation of the swing motor to the upper swing body, a first rotation detection unit that acquires rotation information of the swing motor, and a second that acquires the rotation information of the upper swing body. A rotation detecting means, a turning motor driver for driving the turning motor, and a controller for controlling the turning motor driver are provided. The controller and the swing motor driver control the swing motor based on the rotation information of the swing motor and the rotation information of the upper swing body.
According to this aspect, by providing the second rotation detecting means, it is possible to directly obtain the rotation information such as the actual position, speed, acceleration and the like of the upper swing body, and to reflect it in the control of the swing motor. it can.

A swing device according to an aspect includes a swing motor, a speed reducer that transmits rotation of the swing motor to the upper swing body, a swing motor driver that drives the swing motor, and (i) when the swing motor is rotated, the upper swing body rotates. In the non-slipping section, the swing motor driver is controlled according to the operation command value, and (ii) in the idle section where the upper swing body does not rotate even if the turning motor is rotated, the swing motor is operated until reaching the non-spinning section. And a controller that controls the turning motor driver so as to rotate quickly and to reduce the rotational speed or torque when reaching the non-idling section.

According to this aspect, in the backlash section where the swing motor does not contact the speed reducer, the swing motor is quickly rotated, and immediately before the collision, the rotation speed or torque is reduced to a level that can sufficiently suppress vibration. The vibration can be suppressed while maintaining the motion performance of the revolving structure.

The turning device may further include a first rotation detection unit that acquires rotation information of the turning motor and a second rotation detection unit that acquires rotation information of the upper swing body. The controller may determine the non-slipping section and the idling section based on the outputs of the first rotation detecting means and the second rotation detecting means, and may acquire the position of the turning motor in the idling section.
By monitoring the rotation information of the upper swing body in addition to the rotation information of the swing motor, it is possible to discriminate between the non-slipping section and the idling section, and it is possible to detect the relative positions of the swing motor and the upper swing body.

The controller, based on the difference between the first angle information indicating the rotation angle of the motor coordinate system (converted into the motor shaft) of the swing motor and the second angle information indicating the rotation angle of the motor coordinate system of the upper swing body, You may acquire the position of the turning motor in the inside.
The difference between the first angle information and the second angle information represents the relative position of the swing motor and the upper swing body. Specifically, the difference maintains a constant value of the maximum value or the minimum value in the non-free running section, and the free running section. , The difference transitions between a minimum value and a maximum value. Therefore, by monitoring the difference, the position of the turning motor in the idling section can be acquired.

The controller rotates the swing motor in the first direction across the idling section and then rotates in the second direction across the idling section; and first angle information indicating the rotation angle of the motor coordinate system of the swing motor; You may perform the step which acquires the difference with the 2nd angle information which shows the rotation angle of the motor coordinate system of an upper revolving body, and the step which acquires the maximum value and minimum value of a difference.
By measuring the maximum value and the minimum value of the difference, high-precision control is possible regardless of secular changes due to gear wear or the like.

The controller may further execute a step of setting a difference between the maximum value and the minimum value as a backlash amount corresponding to the idling section.
Thereby, the length of the backlash section can be measured.

The controller may further execute a step of holding an average value of the maximum value and the minimum value of the difference or one of the maximum value and the minimum value as an offset amount.
Thereby, the offset amount of 1st angle information and 2nd angle information can be updated based on a measured value.

(I) In the non-idling section, the controller generates a speed command value corresponding to the operation command value, and the swing motor driver drives the swing motor so that the detected value of the rotation speed of the swing motor matches the speed command value. May be. (Ii) The idling section includes a first section and a second section, and the controller generates a torque command value instructing a predetermined maximum acceleration torque in the first section, and instructs a predetermined maximum deceleration torque in the second section. A torque command value to be generated may be generated. In the idling section, the swing motor driver may drive the swing motor with a torque corresponding to the torque command value.

Another aspect of the present invention also relates to a turning device. The swing device includes a swing motor, a speed reducer that transmits the rotation of the swing motor to the upper swing body, a swing motor driver that drives the swing motor, a first rotation detection unit that acquires rotation information of the swing motor, and an upper swing Second rotation detection means for acquiring body rotation information, rotation angle of the motor coordinate system of the swing motor obtained by the first rotation detection means, and rotation of the motor coordinate system of the upper swing body obtained by the second rotation detection means Based on the difference from the corner, when the difference is a predetermined maximum or minimum value, it is determined that the upper revolving body rotates when the turning motor is rotated, and the difference is between the maximum value and the minimum value. There is provided a controller for determining an idling section where the upper swing body does not rotate even when the swing motor is rotated.

According to this aspect, the second rotation detection means for acquiring the rotation information of the upper swing body is provided, and the difference between the rotation angle of the upper swing body and the rotation angle of the swing motor is monitored, so that the idling section and the non-spinning section are detected. Can be judged.

The controller may detect the rotation angle (position) of the turning motor in the idling section based on the distance between the difference and the maximum value or the distance between the difference and the minimum value.
If the position of the swing motor in the idling section can be detected, the position (that is, the angle) from the idling section to the non-idling section can be estimated, or the timing of the collision between the swiveling motor gear and the reduction gear can be predicted. Appropriate control for suppressing vibration can be performed.

It should be noted that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention that are mutually replaced between methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

According to the present invention, vibration can be suppressed while maintaining the motion performance of the revolving structure.

It is a perspective view which shows the external appearance of the shovel which is an example of the construction machine which concerns on embodiment. It is a block diagram, such as an electric system and a hydraulic system, of the excavator according to the embodiment. It is a block diagram which shows the structure of the electric turning apparatus which concerns on embodiment. It is a block diagram which shows the structure of the electric turning apparatus which concerns on embodiment. It is an operation | movement waveform diagram of the electric turning apparatus which concerns on embodiment. It is an operation | movement waveform diagram of the electric swivel device which concerns on a comparison technique. It is a block diagram of the controller regarding position estimation. FIGS. 8A to 8G are views showing the teeth of the turning motor and the teeth of the speed reducer. It is a figure which shows the angle of a turning motor, and the angle of a turning body. It is a block diagram of a backlash acquisition part and an offset acquisition part. It is a block diagram of a controller concerning the 1st modification. It is a block diagram which shows the structure of the electric turning apparatus which concerns on a 5th modification. It is a block diagram which shows the structure of the electric turning apparatus which concerns on a 6th modification or a 7th modification.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

FIG. 1 is a perspective view showing an appearance of an excavator 1 that is an example of a construction machine according to an embodiment. The excavator 1 mainly includes a traveling mechanism 2 and an upper revolving body (hereinafter also simply referred to as a revolving body) 4 that is rotatably mounted on the upper portion of the traveling mechanism 2 via a revolving mechanism 3.

The swing body 4 is attached with a boom 5, an arm 6 linked to the tip of the boom 5, and a bucket 10 linked to the tip of the arm 6. The bucket 10 is a facility for capturing suspended loads such as earth and sand and steel materials. The boom 5, the arm 6, and the bucket 10 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively. Further, the revolving body 4 is provided with a power source such as a driver's cab 4a for accommodating an operator who operates the position of the bucket 10, excitation operation and release operation, and an engine 11 for generating hydraulic pressure. The engine 11 is composed of, for example, a diesel engine.

FIG. 2 is a block diagram of the electric system and hydraulic system of the excavator 1 according to the embodiment. In FIG. 2, the mechanical power transmission system is indicated by a double line, the hydraulic system is indicated by a thick solid line, the steering system is indicated by a broken line, and the electrical system is indicated by a thin solid line.

The excavator 1 includes a motor generator 12 and a speed reducer 13, and the rotation shafts of the engine 11 and the motor generator 12 are connected to each other by being connected to the input shaft of the speed reducer 13. When the load of the engine 11 is large, the motor generator 12 assists (assists) the driving force of the engine 11 with its own driving force, and the driving force of the motor generator 12 passes through the output shaft of the speed reducer 13 to the main pump 14. Communicated. On the other hand, when the load on the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 via the speed reducer 13, so that the motor generator 12 generates power. The motor generator 12 is configured by, for example, an IPM (Interior / Permanent / Magnetic) motor in which a magnet is embedded in a rotor. Switching between driving of the motor generator 12 and power generation is performed by the controller 30 that controls driving of the electric system in the excavator 1 according to the load of the engine 11 and the like.

A main pump 14 and a pilot pump 15 are connected to the output shaft of the speed reducer 13, and a control valve 17 is connected to the main pump 14 via a high pressure hydraulic line 16. The control valve 17 is a device that controls the hydraulic system in the excavator 1. In addition to the

hydraulic motors

2A and 2B for driving the traveling mechanism 2 shown in FIG. 1, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 are connected to the control valve 17 via a high pressure hydraulic line. The control valve 17 controls the hydraulic pressure supplied to them according to the operation input of the driver.

An operating device 26 (operating means) is connected to the pilot pump 15 via a pilot line 25. The operating device 26 is an operating device for operating the turning electric motor 21, the traveling mechanism 2, the boom 5, the arm 6, and the bucket 10, and is operated by an operator. A control valve 17 is connected to the operating device 26 via a hydraulic line 27, and a pressure sensor 29 is connected via a hydraulic line 28. The operating device 26 converts the hydraulic pressure (primary hydraulic pressure) supplied through the pilot line 25 into a hydraulic pressure (secondary hydraulic pressure) corresponding to the operation amount of the operator and outputs the hydraulic pressure. The secondary hydraulic pressure output from the operating device 26 is supplied to the control valve 17 through the hydraulic line 27 and detected by the pressure sensor 29.

When the operation for turning the turning mechanism 3 is input to the operation device 26, the pressure sensor 29 detects this operation amount as a change in the hydraulic pressure in the hydraulic line 28. The pressure sensor 29 outputs an electrical signal indicating the hydraulic pressure in the hydraulic line 28. This electric signal is input to the controller 30 and used for driving control of the turning electric motor 21.

The controller 30 is configured by a processing unit including a CPU (Central Processing Unit) and an internal memory, and is realized by the CPU executing a drive control program stored in the internal memory. The controller 30 receives operation inputs from various sensors and the operation device 26 and the like, and performs drive control of the

inverters

18A and 18C, the power storage means 20, and the like.

The hydraulic motor 40 is configured to be rotated by oil discharged from the boom cylinder 7 when the boom 5 is lowered, and is provided for converting energy when the boom 5 is lowered according to gravity into rotational force. It has been. The hydraulic motor 40 is provided in the hydraulic pipe 7 A between the control valve 17 and the boom cylinder 7.

The turning electric motor 21 is provided in the turning mechanism 3 in FIG. 1 and rotates the upper turning body 4. The turning electric motor 21 is an AC electric motor and is a power source of the turning mechanism 3 for turning the turning body 4. A resolver 22, a mechanical brake 23, and a turning speed reducer 24 are connected to the rotating shaft 21 A of the turning electric motor 21. The turning inverter 18 C receives electric power from the power storage means 20 and drives the turning electric motor 21. Further, during the regenerative operation of the turning electric motor 21, the electric power from the turning electric motor 21 is collected in the power storage means 20.

When the turning electric motor 21 performs a power running operation, the rotational force of the rotational driving force of the turning electric motor 21 is amplified by the turning speed reducer 24, and the turning body 4 is subjected to acceleration / deceleration control to perform rotational movement. Further, due to the inertial rotation of the swing body 4, the rotation speed is increased by the swing speed reducer 24 and transmitted to the swing electric motor 21 to generate regenerative power.

The resolver 22 is a sensor that detects the rotation position and rotation angle of the rotation shaft 21A of the turning electric motor 21, and mechanically connected to the turning electric motor 21 to detect the rotation angle and rotation direction of the rotation shaft 21A. When the resolver 22 detects the rotation angle of the rotation shaft 21A, the rotation angle and the rotation direction of the turning mechanism 3 are derived. The mechanical brake 23 is a braking device that generates a mechanical braking force, and mechanically stops the rotating shaft 21 A of the turning electric motor 21 according to a command from the controller 30. The turning speed reducer 24 is a speed reducer that reduces the rotational speed of the rotating shaft 21 A of the turning electric motor 21 and mechanically transmits it to the turning mechanism 3.

Next, the electrical system will be described in detail. The electric system mainly includes a controller 30, power storage means 20, and inverters 18A to 18C.

(assist)
The motor generator 12 is connected to the secondary side (output) end of the assist inverter 18A. The inverter 18A controls the operation of the motor generator 12 based on a command from the assist inverter controller 30A that is a part of the controller 30.

(Turning)
The turning electric motor 21, the resolver 22, the mechanical brake 23, the turning speed reducer 24, the turning inverter 18 C and the turning inverter controller 30 C that is a part of the controller 30 constitute an electric turning device 500.
The turning electric motor 21 is AC driven by the turning inverter 18C in accordance with a PWM (Pulse Width Modulation) control command. As the turning electric motor 21, for example, a magnet-embedded IPM motor is suitable.

The turning inverter controller 30C receives a rotational speed command corresponding to the operation input, and controls the turning inverter 18C so that the turning speed of the turning electric motor 21 detected by the resolver 22 matches the rotational speed command.

(Power supply)
The power storage means 20 includes, for example, a battery that is a storage battery, a step-up / down converter (bidirectional DC / DC converter) that controls charging / discharging of the battery, and a DC bus including positive and negative DC wirings (not shown). ) As the electric storage device, a rechargeable secondary battery such as a lithium ion battery, a capacitor, or any other form of power source capable of transferring power may be used. The primary side (DC input) of each of the

inverters

18A and 18C is connected to the DC bus. The converter controller, which is a part of the controller 30, boosts the bidirectional DC / DC converter when the motor generator 12 or the like is in a power running operation, and bidirectional when the motor generator 12 or the like is in a regenerative operation. The DC / DC converter is stepped down, and the electric power generated by the motor generator 12 is collected in the battery. As a result, the voltage of the DC bus (DC link voltage) is kept at a constant value.

The above is the overall configuration of the excavator 1. Next, the electric swing device 500 according to the embodiment will be described in detail.

FIG. 3 is a block diagram showing a configuration of the electric swivel device 500 according to the embodiment. The electric turning device 500 mainly includes a turning motor 502, a speed reducer 504, a turning motor driver 506, and a controller 520.

The turning motor 502 corresponds to the turning electric motor 21 of FIG. The speed reducer 504 corresponds to the turning speed reducer 24 of FIG. 2 and transmits the rotation of the turning motor 502 to the upper turning body 4. Reducer 504 has a non-zero backlash.

The controller 520 corresponds to an inverter controller 30C that is a part of the controller 30 in FIG.

2 has a lever for turning, and an operation amount (operation angle) of the lever is a control command for the upper turning body 4. For example, the operation amount of the lever is an operation command value S1 for instructing the rotation speed of the revolving structure 4. The controller 520 receives the operation command value S1 and generates a control command value S2 for controlling the rotation of the swing motor 502 based on the operation command value S1. In the computerized construction, the operation command value S1 may be generated by a computer.

The turning motor driver 506 corresponds to the inverter controller 30C and the turning inverter 18C in FIG. The swing motor driver 506 performs feedback control of the swing motor 502 based on the control command value S2. For example, the control command value S2 may be the speed command value ω _REF of the turning motor 502. The first rotation detection means 508 acquires rotation information (first rotation information) S3 of the turning motor 502. The first rotation detecting means 508 is a rotary encoder and corresponds to the resolver 22 in FIG. Alternatively, the first rotation detection means 508 may be a hall sensor. Alternatively, the swing motor 502 may be sensorlessly driven, and in this case, the first rotation detection unit 508 may detect rotation information based on the output of the counter electromotive force detection comparator used in the sensorless drive.

The first rotation information S3 includes a speed detection value ω _RES indicating the rotation speed of the turning motor 502. The swing motor driver 506 feedback-controls the current of the swing motor 502, that is, the torque τ so that the speed detection value ω _RES matches the speed command value ω _REF .

A section swing body 4 and is rotated to rotate the swing motor 502, is defined as "non-slip section T _A ', a section be rotated is turning body 4 does not rotate the swing motor 502," slip section T _B " It is defined as The controller 520, in (i) non-slip section _{T A,} controls the turning motor driver 506 in accordance with an operation command value S1. Specifically, a speed command value S2 corresponding to the operation command value S1 is output.

The controller 520, (ii) in the slip section T _B, such that the turning motor 502 until reaching the non-slip section T _A is rotated at high speed, the rotational speed or torque is reduced when reaching the non-slip section T _A The turning motor driver 506 is controlled.

In this embodiment, the controller 520 determines that slip section T _B, rotates rapidly the swing motor 502 in the slip section T _B. (Ii) slip section _{T B} includes a second section _{T B2} followed by the first interval _{T B1.} The controller 520 generates a torque command value S4 instructing a predetermined maximum acceleration torque τ _ACC in the first interval T _B1 , and generates a torque command value S4 instructing a predetermined maximum deceleration torque τ _BRK in the second interval T _B2 . To do. Turning motor driver 506, the slip section _{T B,} drives the turning motor 502 by a torque τ in accordance with the torque command value S4.

FIG. 4 is a block diagram illustrating a configuration example of the turning motor driver 506. The swing motor driver 506 includes a subtracter 540, a PI (proportional / integral) controller 542, and an inverter 548. The subtractor 540 generates an error Δω between the speed command value ω _REF that is the control command value S 2 and the speed detection value ω _RES from the first rotation detection unit 508. The PI controller 542 receives the error Δω and performs a PI calculation to generate a torque command value τ _REF . Instead of PI control, P control or PID control may be used.

The inverter 548 supplies a drive current corresponding to the torque command value τ _REF to the swing motor 502 and controls the rotation of the swing motor 502.

The swing motor driver 506 further includes a selector 544. Further to the swing motor driver 506 from the controller 520, interval control signal S5 indicating which slip section T _B which is unsubstituted slip section T _A is input. The selector 544, when the interval control signal S5 indicates a non slip section _{T A,} selects the output of the PI controller 542, when the interval control signal S5 indicates a slip section _{T B,} selects the torque command value S4. The proportional gain, integral gain of PI controller 542, interval control signal S5 while showing a slip section T _B, is set to zero.

The above is the configuration of the turning motor driver 506. Note that the subtractor 540, the PI controller 542, and the selector 544 may have a function realized by a combination of hardware such as a microcomputer and a processor and a software program, and need not be provided as individual hardware.

Next, the operation of the electric turning device 500 will be described. FIG. 5 is an operation waveform diagram in the idling section of the electric swivel device 500 according to the embodiment. FIG. 6 is an operation waveform diagram in the idling section of the electric swivel device according to the comparative technique. The advantages of the electric swivel device 500 according to the embodiment will become clear by comparison with the electric swivel device according to the comparative technique.

Therefore, referring to FIG. 6, the operation of the electric swivel device according to the comparative technique will be described first. FIG. 6 shows the control. Prior to time t0, the swing motor and the swing body are stopped. In the electric swivel device according to the comparative technique, the motor torque is output according to the speed command during the idling section from the time t0 to the time t2 of the rotation start of the swivel motor. This speed command slowly rises from 0 rpm to about 150 rpm in order to reduce the impact caused by the collision. As a result, the turning motor rotates slowly, and it takes about 0.07 s until the idling section ends.

Next, with reference to FIG. 5, the operation of the electric swivel device 500 according to the embodiment will be described. In the electric swing device 500, the rotation speed of the swing motor quickly rises to near its peak value of 450 rmp within a short time (about 0.01 seconds in FIG. 5) after the rotation start time t0 of the swing motor. Specifically, the maximum acceleration torque tau _ACC is applied in the first period T _B1 of slip section T _B, the rotational speed of the swing motor rises sharply in a short time. When the time t1 into the second section T _B2, given the maximum deceleration torque tau _BRK, rotational speed of the swing motor, the vibration is reduced to a sufficient suppressible range (20 rpm in this case). At time t2, the idling section ends, but the motor torque at this time is substantially zero, the turning motor is merely rotating (idling) with inertia, and the number of revolutions is sufficiently low. Therefore, the vibration generated at the collision time t2 is significantly suppressed as compared with the comparative technique.

The end time t2 of the idling section is about 0.03 seconds, which is shorter than the end time t2 = 0.07 seconds in FIG. 6, that is, the responsiveness is not sacrificed as compared with the comparative technique, rather It has been improved. This is because the rotational speed is rapidly increased immediately after the activation time t0.

The above is the operation of the electric swivel device 500. Thus, according to the electric turning apparatus 500, it is possible to suppress vibration while maintaining the motion performance of the turning body. Since vibration can be suppressed, the load on the operator can be reduced and work efficiency can be increased, or noise and the like on the surroundings of the workplace can be reduced.

Subsequently, the determination of the non-slip section _{T A} and slip section _{T B} in the controller 520, as well as the estimation of the position of the swing motor 502 in slip section _T in _B will be described.

As shown in FIG. 3, the electric turning device 500 acquires the rotation information (second rotation information) S5 of the turning body 4 in addition to the first rotation detection means 508 that acquires the rotation information S3 of the turning motor 502. Two rotation detection means 510 is further provided.

Controller 520 outputs theta ₁ between the first speed detecting means 508 second rotation detecting unit 510, based on the theta _2, with determining the non-slip section _{T A} and slip section _{T B,} turning the slip section _T in _B motor The position of 502 is acquired. The output θ ₁ indicates the position (rotation angle) of the swing motor 502, and θ ₂ indicates the position (rotation angle) of the swing body 4.

When the swing motor 502 is in contact with the reduction gear 504, the angle θ ₂ of the swing body 4 is dependent on the position θ ₁ of the swing motor 502. The teeth are touched when turning, decelerating, and stopping. On the other hand, when no tooth contact, the angle theta ₂ of the swing body 4 is not dependent on the angle theta ₁ of the turning motor 502. The electric swivel device 500 of FIG. 3 detects the angle θ ₂ of the swivel body 4 when the tooth is not in contact by providing the second rotation detecting means 510, and is relative to the angle θ ₁ of the swivel motor 502. Based on this, the positional relationship between them is estimated by calculation.

FIG. 7 is a block diagram of the controller 520 related to position estimation. The controller 520 includes a non-slipping section command value generation unit 532, an idling section command value generation unit 534, and a position estimation unit 536.

The non-slipping section command value generation unit 532 generates a control command value S2 that is the rotation command value ω _REF in the non-slipping section. The idling section command value generation unit 534 generates a torque command value S4 (τ _REF ) for sudden acceleration and sudden braking in the idling section. Position estimating unit 536 receives the angle theta ₂ of the angle theta ₁ with the swing body 4 of the swing motor 502, it is determined which of the non-slip section T _A slip section T _B, also in the slip section T _B The position of the turning motor 502 in the backlash is estimated. Specifically, the position estimation unit 536 includes first angle information θ _m1 indicating the rotation angle of the motor coordinate system of the swing motor 502 and second angle information θ _m2 indicating the rotation angle of the motor coordinate system of the swing body 4. difference, i.e. based on their relative positions, acquires the position of the swing motor 502 in slip section T in _B.

The position estimation unit 536 includes a converter 522, a subtracter 524, a position calculation unit 526, a backlash acquisition unit 528, and an offset acquisition unit 530.

Convert 522, the angle theta ₁ of the turning motor 502, receives the angle theta ₂ of the rotary body 4, the first angle information of their common motor coordinate system theta _m1, into a second angle information theta _{m @ 2.} The reduction ratio of the reduction gear 504 is used for the conversion. The subtractor 524 calculates a difference Δθ _m between the first angle information θ _m1 and the second angle information θ _m2 . The difference Δθ _m indicates the relative position of the swing motor 502 and the swing body 4.

Position calculating unit 526, based on the difference [Delta] [theta] _m, as well as determining the non-slip section T _A and is either idle interval T _B, calculates the position of the swing motor 502 in the backlash in slip section T _B.

FIGS. 8A to 8G are views showing the tooth T1 on the turning motor shaft side of the reduction gear 504 and the tooth T2 on the turning shaft side. The position of the tooth T1 on the motor shaft side is the rotation angle θ _m1 of the turning motor 502, and the position of the tooth T2 on the turning shaft side is nothing but the rotation angle θ _m2 of the turning body 4. Here, for easy understanding, the gear is shown as a straight line. Here, it is assumed that the origins of θ _m1 and θ _m2 are aligned. Also, the left edges E1 and E2 of each gear give coordinates.

In FIG. 8 (a), the tooth T1 of the motor shaft side is moved to the right within the backlash in slip section T _B. At this time, the tooth T2 on the turning shaft side is stationary. During this time, the difference [Delta] [theta] _m of theta _m1 and theta _{m @ 2} is changed in the first direction. Figure 8 (b) is a boundary of the slip section T _B and the non-slip section T _A, indicating when the tooth T1 of the motor shaft side is brought into contact with the tooth T2 of the turning shaft side. As shown in FIG. 8C, when the motor shaft side tooth T1 further moves in the right direction, the angle θ _{m2 of the} turning shaft changes depending on the angle θ _m1 of the turning motor 502. That is, the difference Δθ _m = θ _m1 −θ _m2 takes a predetermined constant value θ _MAX .

In FIG. 8 (d), the teeth T1 of the motor shaft side is moved to the left direction within the backlash in slip section T _B. At this time, the tooth T2 on the turning shaft side is stationary. During this time, the difference Δθ _m between θ _m1 and θ _m2 changes in the second direction.

FIG. 8 (e) is a boundary of the slip section T _B and the non-slip section T _A, indicating when the tooth T1 of the motor shaft side is brought into contact with the tooth T2 of the turning shaft side. As shown in FIG. 8F, when the tooth T1 on the motor shaft side further moves to the left, the angle θ _m2 of the swing body 4 changes depending on the angle θ _m1 of the swing motor shaft. That is, the difference θ _m1 −θ _m2 takes a predetermined constant value θ _MIN . When the turning motor 502 is rotated in the right direction as shown in FIG. 8G, the turning motor 502 is idled in the backlash, and the difference Δθ _m changes in the first direction.

FIG. 9 is a diagram illustrating the angle θ _m1 of the swing motor 502 and the angle θ _m2 of the swing body 4. 9A to 9G correspond to the respective states of FIGS. 8A to 8G.

Position calculating unit 526, when the difference [Delta] [theta] _m is the maximum value theta _MAX, or when the minimum value theta _MIN, determines that non-slip section _{T A,} the minimum value difference [Delta] [theta] _m is theta _MIN and the maximum value theta _MAX when it is between, it can be determined that the slip section T _B.

The distance between Δθ _m and the minimum value θ _MIN or the distance between Δθ _m and the maximum value θ _MAX represents the position (angle) of the turning motor 502 in the backlash. Therefore, when the turning motor 502 is rotating in the first direction, the first section T _{B1 is} when the distance between Δθ _m and the maximum value θ _MAX is greater than the predetermined value W, and the second section T _B2 is when the distance is smaller. Also good. On the other hand, when the turning motor 502 rotates in the second direction, the first section T _{B1 is} when the distance between Δθ _m and the minimum value θ _MIN is greater than the predetermined value W, and the second section T _B2 is when the distance is smaller. Also good.

Thus, if the minimum value theta _MIN and the maximum value theta _MAX of the difference [Delta] [theta] _m is known, based on the difference [Delta] [theta] _m, the non-slip section T _A, determines the idle period T _B, also turning in backlash The position of the motor 502 can be calculated.

Design values may be used for the minimum value θ _MIN and the maximum value θ _MAX, but they may be actually measured in an actual machine as described below. The following technique is particularly effective when the backlash amount due to gear wear cannot be ignored over time.

The controller 520 executes calibration including the following steps.
Step 1) The turning motor 502 is rotated in the first direction and subsequently rotated in the second direction.
Step 2) In the process of Step 1, the difference between the first angle information θ _m1 indicating the rotation angle of the motor coordinate system of the swing motor 502 and the second angle information θ _m1 indicating the rotation angle of the motor coordinate system of the swing body 4 Obtain Δθ _m .
Step 3) Obtain the maximum value θ _MAX and the minimum value θ _MIN of the difference Δθ _m .
Through the above processing, parameters required by the position calculation unit 526 are calibrated. Controller 520, steps 1-3 repeated multiple times, may obtain the maximum value theta _MAX and the minimum value theta _MIN using statistical processing such as averaging. Calibration may be performed at an appropriate time.

The controller 520 may further execute the following processing.
Step 4) the difference between the maximum value theta _MAX and the minimum value theta _MIN, the backlash amount corresponding to the slip section _{T B.} Step 4 is executed by the backlash acquisition unit 528, and the backlash amount S7 is held. The amount of backlash increases over time due to gear wear. If this process is performed, the rotation control of the idling section can be performed based on the measured accurate backlash amount, and therefore, the performance degradation with time can be suppressed. In addition, when the backlash amount increases to a degree exceeding a certain threshold, it is possible to diagnose wear or failure.

Step 5) An average value of the maximum value θ _MAX and the minimum value θ _MIN is acquired as an offset amount. Step 5 is executed by the offset acquisition unit 530, and the offset amount S8 is held.

In order to actually measure the minimum value θ _MIN and the maximum value θ _MAX , the controller 520 includes a backlash acquisition unit 528 and an offset acquisition unit 530. FIG. 10 is a block diagram of the backlash acquisition unit 528 and the offset acquisition unit 530. In step 3, the peak acquisition unit 550 acquires the maximum value θ _MAX of the difference Δθ _m . In step 3, the bottom acquisition unit 552 acquires the minimum value θ _MIN of the difference Δθ _m .

The subtractor 554 calculates the backlash amount S7. Adder 556 adds maximum value θ _MAX and minimum value θ _MIN , and multiplier 558 multiplies the addition result by 1/2 to calculate offset amount S8.

The following relational expression holds for the backlash amount S7 and the offset amount S8 obtained in this way, and the maximum value θ _MAX and the minimum value θ _MIN .
θ _MAX = S8 + S7 / 2
θ _MIN = S8-S7 / 2
The position calculation unit 526 can calculate the maximum value θ _MAX and the minimum value θ _MIN based on the backlash amount S7 and the offset amount S8.

The offset amount S8 may be defined by the maximum value θ _MAX . In this case, the following relational expression holds.
θ _MAX = S8
θ _MIN = S8-S7

Alternatively, the offset amount S8 may be defined by the minimum value θ _MIN . In this case, the following relational expression holds.
θ _MAX = S8 + S7
θ _MIN = S8

The present invention has been described above based on the embodiments. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, and various modifications are possible, and such modifications are within the scope of the present invention. It is a place. Hereinafter, such modifications will be described.

(First modification)
In the embodiment, the slip section T _B, the swing motor 502 to accelerate rapidly, in order to decelerate before collision with the gear has been subjected to torque control present invention is not limited thereto. FIG. 11 is a block diagram of the controller 520a according to the first modification.
Slip section command value generating unit 534, the slip section T _B, and generates a speed command value S9 to instruct the motor speed changes as shown in FIG. The selector 535, interval control signal S5 selects the control command value S2 when referring to non-slip section T _A, interval control signal S5 selects the speed command value S9 when indicating the idle interval T _B. The swing motor driver 506 controls the swing motor 502 based on the speed command value ω _REF output from the controller 520.

(Second modification)
Or as another variation, the slip section T _B, using the position control, the turning motor 502 to accelerate rapidly, may be decelerated before colliding with the gear.

(Third Modification)
Method of determining non-slip section T _A and slip section T _B is not limited to that described in the embodiment. For example, the load inertia moment amount may be estimated from the relationship between the drive current of the swing motor and the acceleration of the swing motor, and a section in which the estimated load inertia moment amount does not include the rotor equivalent may be estimated as the idling section.

(Fourth modification)
In the embodiment, the case where the position estimation unit 536 holds the backlash amount S7 and the offset amount S8 has been described, but the present invention is not limited to this. For example, the position estimation unit 536 may store the minimum value θ _MIN and the maximum value θ _MAX of the difference Δθ _m and obtain the backlash amount S7 and the offset amount S8 by calculation. The position estimation unit 536 may _store at least two of the backlash amount S7, the offset amount S8, the minimum value θ _MIN , and the maximum value θ _MAX and obtain the rest by calculation.

(5th modification)
FIG. 12 is a block diagram showing a configuration of an electric swivel device 500a according to the fifth modification. The basic configuration of the electric swivel device 500a is the same as that of FIG.

The controller 520 receives an operation command value S1 that indicates the position of the revolving structure 4. In addition, angle information θ ₂ indicating the actual position of the revolving structure 4 generated by the second rotation detection unit 510 is input to the controller 520. Angle information theta ₂ corresponds to the position feedback value theta _FB. The operation command value S1 may correspond to the amount of operation of the turning lever by the operator. Alternatively, the operation command value S1 may be generated by a computer in information construction.

The controller 520 includes a so-called position controller, the position feedback value theta _FB indicating the angle information theta ₂ is, to match the position command value theta _REF indicated by the operation command S1, the control command value S2 for turning motor driver 506 Generate. Control command value S2 may be the speed command value omega _REF.

The swing motor driver 506 performs feedback control of the swing motor 502 based on the speed command value ω _REF from the controller 520. The first rotation detection means 508 acquires rotation information (first rotation information) S3 of the turning motor 502. The first rotation information S3 includes a speed detection value ω _RES indicating the rotation speed of the turning motor 502. The swing motor driver 506 may include a speed controller that feedback-controls the current of the swing motor 502, that is, the torque τ, so that the speed detection value ω _RES matches the speed command value ω _REF .

According to the fifth modification, by using the second rotation information from the second rotation detecting unit 510 without detecting the idling section and the non-idling section, the position θ of the swing body 4 is directly controlled. And its position can be accurately controlled.

(Sixth Modification)
FIG. 13 is a block diagram showing a configuration of an electric swivel device 500b according to a sixth modification. The basic configuration of the electric swivel device 500b is the same as that of FIG. The controller 520 includes a position controller, and controls the control command value S2 (speed command value ω _REF so that the position command indicated by the operation command value S1 coincides with the position feedback signal θ ₁ detected by the first rotation detecting means 508. ) Is generated.

The rotation information S6 of the revolving structure 4 generated by the second rotation detection unit 510 is input to the controller 520. The rotation information S6 includes at least one of the position θ ₂ , the speed ω ₂ , and the acceleration α ₂ of the revolving structure 4. Controller 520, the rotation information S6 in the swing body 4, S1, S2, is reflected in the at least one theta _1. For example, the controller 520 utilizes the rotation information S6, S1, S2, correcting at least one theta _1.

For example, when the rotation information S6 detects a rotation delay of the turning motor 502, the output value or the input value of the position controller may be changed so that the number of rotations increases. Correction S1, S2, may be multiplied by a factor in at least one theta _1, may be performed by table lookup.

(Seventh Modification)
With continued reference to FIG. 13, a seventh modification will be described. In the seventh modification, rotation information S6 generated by the second rotation detection unit 510 is input to the turning motor driver 506 in addition to or instead of the controller 520. The turning motor driver 506 corrects or corrects S2, ω _RES , and a torque command (current command) as an output based on the rotation information S6 of the turning body 4. For example, when the torque information of the swing motor 502 is detected from the rotation information S6, the output value or the input value of the position controller may be changed so that the torque increases (decreases).

DESCRIPTION OF SYMBOLS 1 ... Excavator, 2 ... Traveling mechanism, 2A ... Hydraulic motor, 3 ... Turning mechanism, 4 ... Turning body, 4a ... Driver's cab, 5 ... Boom, 6 ... Arm, 7 ... Boom cylinder, 7A ... Hydraulic pipe, 8 ... Arm Cylinder, 9 ... Bucket cylinder, 10 ... Bucket, 11 ... Engine, 12 ... Motor generator, 13 ... Reduction gear, 14 ... Main pump, 15 ... Pilot pump, 16 ... High pressure hydraulic line, 17 ... Control valve, 18, 18A , 18B ... inverter, 18C ... inverter for turning, 20 ... power storage means, 21 ... electric motor for turning, 21A ... rotating shaft, 22 ... resolver, 23 ... mechanical brake, 24 ... turning speed reducer, 25 ... pilot line, 26 ... operation Apparatus, 27, 28 ... Hydraulic line, 29 ... Pressure sensor, 30 ... Controller, 30A, 30C ... Inverter controller, 40 ... Hydraulic pressure , 42 ... Boom regeneration generator, 500 ... Electric turning device, 502 ... Turning motor, 504 ... Reduction gear, 506 ... Turning motor driver, 508 ... First rotation detection means, 510 ... Second rotation detection means, 520 ... Controller, 522 ... Converter, 524 ... Subtractor, 526 ... Position calculation unit, 528 ... Backlash acquisition unit, 530 ... Offset acquisition unit, 532 ... Non-slipping section command value generation unit, 534 ... Idle section command value generation unit 536 ... Position estimation unit, 540 ... Subtractor, 542 ... PI controller, 544 ... Selector, 548 ... Inverter, 550 ..., S1 ... Operation command value, S2 ... Control command value, S3 ... First rotation information, S4 ... Torque Command value, S5: Section control signal, S7: Backlash amount, S8: Offset amount.

The present invention can be used for construction machines and the like.

Claims

A swiveling device that is mounted on a shovel including a traveling mechanism and an upper swinging body that is swingably mounted on the traveling mechanism, and that swings the upper swinging body based on an operation command value,
A swing motor;
A speed reducer that transmits the rotation of the swing motor to the upper swing body;
First rotation detecting means for acquiring rotation information of the turning motor;
Second rotation detection means for acquiring rotation information of the upper swing body;
A turning motor driver for driving the turning motor;
A controller for controlling the turning motor driver;
With
The turning device characterized in that the controller and the turning motor driver control the turning motor based on rotation information of the turning motor and rotation information of the upper turning body.
The controller is
(I) controlling the swing motor driver in accordance with the operation command value in a non-slipping section in which the upper swing body rotates when the swing motor rotates, and (ii) the upper portion even if the swing motor is rotated In the idling section where the turning body does not rotate, the swiveling motor driver is controlled so that the swiveling motor rotates at a high speed before reaching the non-idling section, and the rotation speed or torque decreases when reaching the non-idling section. The swivel device according to claim 1.
The controller determines the non-idling section and the idling section based on the outputs of the first rotation detecting means and the second rotation detecting means, and acquires the position of the swing motor in the idling section. The swivel device according to claim 1 or 2, characterized in that
The controller is configured to determine the difference between the first angle information indicating the rotation angle of the motor coordinate system of the swing motor and the second angle information indicating the rotation angle of the motor coordinate system of the upper swing body. The turning device according to claim 3, wherein the position of the turning motor is acquired.
The controller is
Rotating the swivel motor in a first direction and subsequently rotating in a second direction;
Obtaining a difference between first angle information indicating a rotation angle of the motor coordinate system of the swing motor and second angle information indicating a rotation angle of the motor coordinate system of the upper swing body;
Obtaining a maximum value and a minimum value of the difference;
The swiveling device according to any one of claims 1 to 4, wherein:
The turning device according to claim 5, wherein the controller further executes a step of setting a difference between the maximum value and the minimum value as a backlash amount corresponding to the idling section.
7. The controller according to claim 5, wherein the controller further executes a step of holding an average value of the maximum value and the minimum value of the difference or one of the maximum value and the minimum value as an offset amount. The swivel device described.
(I) In the non-idling section, the controller generates a speed command value corresponding to the operation command value, and the swing motor driver has a detected value of the rotation speed of the swing motor that matches the speed command value. Drive the swivel motor as
(Ii) The idling section includes a first section and a second section, and the controller generates a torque command value indicating a predetermined maximum acceleration torque in the first section, and a predetermined maximum in the second section. 8. The torque command value for instructing a deceleration torque is generated, and the swing motor driver drives the swing motor with a torque corresponding to the torque command value. Swivel device.
A swiveling device that is mounted on a shovel including a traveling mechanism and an upper swinging body that is swingably mounted on the traveling mechanism, and that swings the upper swinging body based on an operation command value,
A swing motor;
A speed reducer that transmits the rotation of the swing motor to the upper swing body;
A turning motor driver for driving the turning motor;
First rotation detecting means for acquiring rotation information of the turning motor;
Second rotation detection means for acquiring rotation information of the upper swing body;
Based on the difference between the rotation angle of the motor coordinate system of the swing motor obtained by the first rotation detection means and the rotation angle of the motor coordinate system of the upper swing body obtained by the second rotation detection means, the difference is a predetermined value. When the swing motor is rotated when it is the maximum value or the minimum value, the upper swing body is determined to be a non-free running section, and when the difference is between the maximum value and the minimum value, the swing motor A controller that determines an idle section in which the upper swing body does not rotate even if the upper rotating body is rotated.
A swivel device comprising:
The turning according to claim 9, wherein the controller detects a rotation angle of the turning motor in the idling section based on the distance between the difference and the maximum value or the distance between the difference and the minimum value. apparatus.
The controller is
Rotating the swivel motor in a first direction and subsequently rotating in a second direction;
Obtaining a difference between first angle information indicating a rotation angle of the motor coordinate system of the swing motor and second angle information indicating a rotation angle of the motor coordinate system of the upper swing body;
Holding the difference between the maximum value and the minimum value of the difference as a backlash amount;
The swiveling device according to claim 9 or 10, wherein: