WO2012160985A1 - 建設機械の電動駆動装置 - Google Patents
建設機械の電動駆動装置 Download PDFInfo
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- WO2012160985A1 WO2012160985A1 PCT/JP2012/061981 JP2012061981W WO2012160985A1 WO 2012160985 A1 WO2012160985 A1 WO 2012160985A1 JP 2012061981 W JP2012061981 W JP 2012061981W WO 2012160985 A1 WO2012160985 A1 WO 2012160985A1
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- WIPO (PCT)
- Prior art keywords
- pressure
- generator
- motor
- control
- hydraulic pump
- Prior art date
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Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/14—Booms only for booms with cable suspension arrangements; Cable suspensions
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/30—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom
- E02F3/32—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with a dipper-arm pivoted on a cantilever beam, i.e. boom working downwardly and towards the machine, e.g. with backhoes
- E02F3/325—Backhoes of the miniature type
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/38—Cantilever beams, i.e. booms;, e.g. manufacturing processes, forms, geometry or materials used for booms; Dipper-arms, e.g. manufacturing processes, forms, geometry or materials used for dipper-arms; Bucket-arms
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/2058—Electric or electro-mechanical or mechanical control devices of vehicle sub-units
- E02F9/2062—Control of propulsion units
- E02F9/207—Control of propulsion units of the type electric propulsion units, e.g. electric motors or generators
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/2058—Electric or electro-mechanical or mechanical control devices of vehicle sub-units
- E02F9/2091—Control of energy storage means for electrical energy, e.g. battery or capacitors
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2217—Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
Definitions
- the present invention relates to a construction machine such as an electric hydraulic excavator, and in particular, an electric motor / generator for driving a hydraulic pump that supplies pressure oil to a plurality of hydraulic actuators, and transfer of electric power between the electric motor / generator.
- the present invention relates to an electric drive device for a construction machine equipped with a power storage device that performs the above.
- a mini excavator as an example of a construction machine (that is, a hydraulic excavator having an operating mass of less than 6 tons) is generally a lower traveling body, an upper revolving body provided on the lower traveling body so as to be able to swivel, and the upper revolving body. And an articulated working machine including a boom, an arm, and a bucket.
- the mini excavator includes, for example, a hydraulic pump, a plurality of hydraulic actuators (specifically, for example, a boom hydraulic cylinder, an arm hydraulic cylinder, a bucket hydraulic cylinder, and the like), and a pressure from the hydraulic pump to the plurality of hydraulic actuators.
- a plurality of directional control valves that respectively control the flow of oil, and operating means that operate the directional switching valves respectively (specifically, for example, a plurality of operating devices that output pilot pressure corresponding to the operating position of the operating lever); It has.
- Some of the above-described electric mini excavators are equipped with a power storage device composed of a plurality of batteries as a power source of the electric motor.
- a power storage device composed of a plurality of batteries as a power source of the electric motor.
- this electric motor-driven excavator with a built-in power storage device, it is not always necessary to connect to an external power source using a power cable.
- movement and turning operations are not limited.
- the turning radius dimension of the rear end of the upper turning body or the entire upper turning body is limited.
- the upper swing body is provided with a driver's cab or the like on which the driver is boarded, and further includes hydraulic equipment including a plurality of directional control valves, a hydraulic pump, and a hydraulic oil tank. Therefore, the space of the battery that can be mounted on the upper swing body is limited so as not to impair the visibility of the driver, and the number of batteries that can be mounted on the upper swing body is limited. Therefore, the power storage capacity of the power storage device mounted on the mini excavator is limited, and the operation time of the mini excavator when the power cable is not connected to the external power source is limited.
- An object of the present invention is to provide an electric drive device for a construction machine that can make the operation time limited by the power storage device mounted on the construction machine longer than the conventional operation by the power generation action of the motor / generator. .
- the present invention provides a power storage device, an electric motor / generator that transfers electric power to and from the electric power storage device, and a variable capacity hydraulic pressure that is driven by the electric motor / generator.
- a pump a plurality of hydraulic actuators, a plurality of operation means for instructing operations of the plurality of hydraulic actuators, and from the hydraulic pump to the plurality of hydraulic actuators according to operation directions and operation amounts of the plurality of operation means.
- an electric drive device for a construction machine having a plurality of directional control valves that respectively control the direction and flow rate of pressure oil to be supplied, pump control means for variably controlling the displacement of the hydraulic pump, and the electric / generator Motor / generator control means for variably controlling the number of rotations, and the pump control means according to a change in the required flow rate based on the operation command amount from each of the plurality of operation means
- command control means for calculating a command value to the motor / generator control means, wherein the motor / generator control means decreases the rotation speed of the motor / generator in response to a decrease in the required flow rate.
- regenerative control is performed to charge the power storage device by converting the inertial force of the rotor of the motor / generator into electric power.
- the regenerative control for charging the power storage device by converting the inertial force of the rotor of the motor / generator into electric power when the motor / generator rotation speed is decreased in accordance with the decrease in the required flow rate.
- the load sensing is such that the differential pressure across each of the plurality of directional control valves is a differential pressure between the discharge pressure of the hydraulic pump and the maximum load pressure of the hydraulic actuators.
- a plurality of pressure compensation valves that control the differential pressure so as to be a differential pressure; and a differential pressure detection unit that detects the load sensing differential pressure, wherein the command control unit detects the load sensing differential pressure detected by the differential pressure detection unit Command values to the pump control means and the motor / generator control means are calculated according to the difference between them, the motor / generator control means,
- the regeneration is performed by charging the power storage device by converting the inertial force of the rotor of the motor / generator into electric power. Please is carried out.
- the load sensing differential pressure exceeds the target value (that is, the required flow rate decreases) and the motor / generator rotation speed is decreased, the inertial force of the motor / generator rotor is reduced.
- the command control means includes a subtraction means for calculating a difference between a load sensing differential pressure detected by the differential pressure detection means and a preset target value; and the subtraction A first low-pass filter that performs a process of removing a change component that is equal to or higher than a preset first frequency, and a difference that is processed by the first low-pass filter according to the difference calculated by the means
- a first command calculation unit that calculates a command value to the pump control unit, and a difference calculated by the subtraction unit is equal to or higher than a second frequency set in advance so as to be smaller than the first frequency.
- a second low-pass filter that performs a process for removing the change component; and a second low-pass filter that calculates a command value to the motor / generator controller in accordance with the difference processed by the second low-pass filter. And a decree calculating means.
- the second command calculation means calculates the difference between the load sensing differential pressure and the target value
- the second low-pass filter means changes the second frequency or more with respect to the difference. Processing to remove components is performed. And since this 2nd frequency is made comparatively small, the sensitivity of the variable control of the rotation speed of an electric motor / generator with respect to the fluctuation
- the first low-pass filter means changes more than the first frequency with respect to the difference. Processing to remove components is performed. And since this 1st frequency is made comparatively large, the sensitivity of the variable control of the displacement of the hydraulic pump with respect to the fluctuation
- the load sensing is such that the differential pressure across each of the plurality of directional control valves is a differential pressure between the discharge pressure of the hydraulic pump and the maximum load pressure of the hydraulic actuators.
- the command control means sets a target value for the discharge pressure of the hydraulic pump based on the maximum load pressure of the plurality of hydraulic actuators detected by the maximum load pressure detection means, and is detected by the discharge pressure detection means.
- command values to the pump control means and the motor / generator control means are calculated according to the difference between them so that the discharge pressure of the hydraulic pump becomes the target value.
- the motor / generator control means uses the inertial force of the rotor of the motor / generator when the discharge pressure of the hydraulic pump exceeds the target value to decrease the rotation speed of the motor / generator. Regenerative control is performed to charge the power storage device by converting to
- the inertia of the rotor of the electric / generator is reduced when the rotational speed of the electric / generator is decreased.
- the command control means sets a target value for the discharge pressure of the hydraulic pump based on the maximum load pressures of the plurality of hydraulic actuators detected by the maximum load pressure detection means.
- Target value setting means for setting, subtracting means for calculating the difference between the discharge pressure of the hydraulic pump detected by the discharge pressure detecting means and the target value set by the target value setting means, and calculation by the subtracting means
- a first low-pass filter means for performing a process of removing a change component having a frequency equal to or higher than a preset first frequency, and the pump control according to the difference processed by the first low-pass filter means.
- a first command calculating means for calculating a command value to the means, and a second frequency preset to be smaller than the first frequency with respect to the difference calculated by the subtracting means.
- a second low-pass filter means for performing processing for removing the above change component; and a second low-pass filter means for calculating a command value to the motor / generator control means in accordance with the difference processed by the second low-pass filter means. Command calculating means.
- the plurality of directional control valves are of an open center type, and a throttle provided downstream of a center bypass flow path of the plurality of directional control valves;
- Control pressure detecting means for detecting an upstream pressure of the throttle as a control pressure, which changes based on a change in at least one of a plurality of directional control valves that switch on the upstream side, and a tilt angle of the hydraulic pump
- a tilt angle detecting means for detecting the rotational speed of the motor / generator, a rotational speed acquiring means for acquiring the rotational speed of the motor / generator, and a tilt angle of the hydraulic pump detected by the tilt angle detecting means and the rotational speed acquiring means.
- a discharge flow rate calculation means for calculating a discharge flow rate of the hydraulic pump based on the rotation speed of the motor / generator obtained in step (i), wherein the command control means is the hydraulic pump calculated by the discharge flow rate calculation means.
- Discharge A target value for the control pressure is set based on the amount, and commands to the pump control means and the motor / generator control means are determined according to the difference between the control pressure detected by the control pressure detection means and the target value.
- the motor / generator control means calculates the inertia of the rotor of the motor / generator when the control pressure exceeds the target value and decreases the rotational speed of the motor / generator. Regenerative control is performed for charging the power storage device by converting power into electric power.
- the control pressure exceeds the target value (that is, the required flow rate is reduced) and the motor / generator rotation speed is decreased, the inertial force of the motor / generator rotor is supplied to the electric power.
- the command control means is a target value setting means for setting a target value for the control pressure based on the discharge flow rate of the hydraulic pump calculated by the discharge flow rate calculation means; Subtracting means for calculating a difference between the control pressure detected by the control pressure detecting means and the target value set by the target value setting means, and a first preset for the difference calculated by the subtracting means.
- a first low-pass filter unit that performs a process of removing a change component having a frequency equal to or higher than a first frequency, and a first command that calculates a command value to the pump control unit according to the difference processed by the first low-pass filter unit
- a second low-pass filter that performs processing for removing a change component equal to or higher than a second frequency set in advance so as to be smaller than the first frequency with respect to the difference calculated by the calculating means and the subtracting means. It has a filter means, and a second command calculating means for calculating a command value for the motor-generator control means in response to the processed difference in the second low-pass filter means.
- a maximum operation amount detection unit that detects a maximum operation amount of the plurality of operation units
- a tilt angle detection unit that detects a tilt angle of the hydraulic pump
- the electric motor A rotation speed acquisition means for detecting the rotation speed of the generator, a tilt angle of the hydraulic pump detected by the tilt angle detection means, and a rotation speed of the motor / generator detected by the rotation speed acquisition means
- Discharge flow rate calculation means for calculating a discharge flow rate of the hydraulic pump based on the flow rate
- the command control means is a required flow rate based on the maximum operation amount of the plurality of operation means detected by the maximum operation amount detection means.
- the motor / generator control means reduces the inertial force of the rotor of the motor / generator when the discharge flow rate of the hydraulic pump exceeds the required flow rate to reduce the rotation speed of the motor / generator. Regenerative control is performed in which the power storage device is charged by converting into electric power.
- the inertia of the rotor of the electric / generator is reduced when the discharge flow rate of the hydraulic pump exceeds the required flow rate (that is, the required flow rate is reduced) to reduce the rotational speed of the electric / generator.
- the command control unit includes a required flow rate setting unit that sets a required flow rate based on the maximum operation amounts of the plurality of operation units detected by the maximum operation amount detection unit.
- a first low-pass filter means for performing a process of removing a change component of the set first frequency or higher, and a command value to the pump control means is calculated according to a difference processed by the first low-pass filter means And a process of removing a change component having a frequency equal to or higher than a second frequency set in advance so as to be smaller than the first frequency with respect to the difference calculated by the first command calculating means and the subtracting means.
- the regeneration control is performed to charge the power storage device by converting the inertial force of the rotor of the motor / generator into electric power.
- the operation time of the construction machine can be lengthened.
- FIG. 3 is a diagram illustrating a configuration related to driving of a boom hydraulic cylinder and an arm hydraulic cylinder as a representative example of the configuration of the electric drive device illustrated in FIG. 2 and a configuration of an LS differential pressure detection device. It is a block diagram showing the functional structure of the LS control apparatus shown by FIG. 2 with a related apparatus.
- FIG. 5 is a diagram for explaining processing of the low-pass filter unit shown in FIG. 4, and represents a change over time in the difference ⁇ Pls before processing as one specific example.
- FIG. 5 is a diagram for explaining processing of the low-pass filter unit shown in FIG. 4, and represents a change with time of ⁇ Pls ′ after processing as one specific example.
- FIG. 5 is a diagram for explaining processing of the low-pass filter unit shown in FIG. 4, and represents a change with time of ⁇ Pls ′′ after processing as one specific example.
- FIG. 3 is a block diagram illustrating a functional configuration of the bidirectional converter illustrated in FIG. 2 together with related devices. It is a figure showing the structure of the LS differential pressure
- FIG. 16 is a block diagram illustrating a functional configuration of the positive control device illustrated in FIG. 15 together with related devices. It is a figure for demonstrating the process of the target value setting part shown by FIG.
- FIG. 1 is a side view showing the overall structure of an electric mini-excavator to which the present invention is applied.
- the driver's front side left side in FIG. 1
- rear side right side in FIG. 1
- left side left side
- FIG. 1 The front side toward the middle page and the right side (back side toward the middle page in FIG. 1) are simply referred to as front side, rear side, left side, and right side.
- an electric mini-excavator includes a crawler type lower traveling body 1, an upper revolving body 2 that is turnably provided on the lower traveling body 1, and a swivel that forms a basic lower structure of the upper revolving body 2.
- a frame 3 a swing post 4 provided on the front side of the revolving frame 3 so as to be turnable in the left-right direction, and an articulated work connected to the swing post 4 so as to be turnable up and down (can be raised and lowered).
- Machine 5 canopy type cab 6 provided on swivel frame 3, and power storage device 7 provided on the rear side of swivel frame 3 and comprising a plurality of batteries (for example, lithium batteries) (see FIG. 2 described later).
- a battery mounting portion 8 in which is stored.
- a power supply socket (not shown) to which a cable from an external power source can be connected is provided on the side of the upper swing body 2.
- the lower traveling body 1 includes a substantially H-shaped track frame 9 as viewed from above, left and right drive wheels 10 rotatably supported in the vicinity of the rear ends of the left and right sides of the track frame 9, and left and right sides of the track frame 9.
- Left and right driven wheels (idlers) 11 rotatably supported in the vicinity of the front ends on both sides, and left and right crawler belts (crawlers) 12 wound around the left and right drive wheels 10 and the driven wheels 11 are provided.
- the left driving wheel 10 that is, the left crawler belt 12
- the right driving wheel is driven by driving the right traveling hydraulic motor 13B (see FIG. 2 described later).
- 10 that is, the right crawler belt 12 rotates.
- a soil removal blade 14 is provided on the front side of the track frame 9 so as to be movable up and down.
- the blade 14 is moved up and down by a telescopic drive of a blade hydraulic cylinder 15 (see FIG. 2 described later). Yes.
- a turning wheel 16 is provided at the center of the track frame 9, and the turning frame 3 is turnable via the turning wheel 16.
- the turning frame 3 (that is, the upper turning body 2) is a turning hydraulic motor 17. It turns by the drive of (refer FIG. 2 mentioned later).
- the swing post 4 is provided on the front side of the swing frame 3 so as to be capable of rotating in the left-right direction, and is rotated in the left-right direction by an expansion / contraction drive of a swing hydraulic cylinder 18 (see FIG. 2 described later). . Thereby, the work machine 5 swings to the left and right.
- the work machine 5 includes a boom 19 connected to the swing post 4 so as to be able to rotate in the vertical direction, an arm 20 connected to the boom 19 so as to be capable of rotating in the vertical direction, and the arm 20 being rotated in the vertical direction. And a bucket 21 connected in a possible manner.
- the boom 19, the arm 20, and the bucket 21 are rotated in the vertical direction by a boom hydraulic cylinder 22, an arm hydraulic cylinder 23, and a bucket hydraulic cylinder 24.
- the driver's cab 6 is provided with a driver seat (seat) 25 on which the driver is seated.
- a driver seat (seat) 25 on which the driver is seated.
- the left and right traveling operation levers 26A and 26B (which are shown in FIG. 1 is shown only 26A).
- a swing operation pedal (not shown) for instructing the operation of the swing hydraulic cylinder 18 by operating in the left-right direction is provided at the right foot portion of the right travel operation lever 26B.
- FIG. 2 is a schematic diagram showing the configuration of the electric drive device of this embodiment provided in the electric mini-excavator described above.
- FIG. 3 shows a configuration related to driving of the boom hydraulic cylinder 22 and the arm hydraulic cylinder 23 as a representative example of the configuration of the electric drive device shown in FIG. 2 and the configuration of the LS differential pressure detection device. It is a hydraulic circuit diagram.
- the electric drive device includes a power storage device 7 composed of a plurality of batteries (only two are shown for convenience in FIG. 2 but actually more), and a power storage device 7 via a bidirectional converter 28.
- An electric motor / generator 29 that exchanges power with each other, a variable displacement hydraulic pump 30 and a fixed displacement pilot pump (not shown) that are driven by the electric motor / generator 29, and the hydraulic pump 30.
- a regulator 31 that variably controls the displacement (in other words, the discharge capacity per rotation), and a plurality of hydraulic actuators (more specifically, the left and right traveling hydraulic motors 13A and 13B, the blade hydraulic cylinder 15, and the swiveling cylinder).
- a valve unit 32 for controlling the flow of pressure oil supplied from the hydraulic pump 30 to a plurality of hydraulic actuators 22, 23 and the like.
- the valve unit 32 includes a plurality of closed center type directional control valves that control the direction and flow rate of the pressure oil supplied from the hydraulic pump 30 to the plurality of hydraulic actuators 22, 23, etc.
- Direction switching valve 33 and arm direction switching valve 34 left and right traveling direction switching valves, blade direction switching valves, turning direction switching valves, swing direction switching valves, and bucket direction switching valves (not shown). These are referred to as direction switching valves 33, 34, etc.).
- the valve unit 32 includes a plurality of pressure compensation valves (specifically, a boom pressure compensation valve 35 and an arm pressure compensation valve 36 shown in FIG.
- left and right traveling pressure compensation valves, blade pressure compensation valves, swing pressure compensation valves, swing pressure compensation valves, and bucket pressure compensation valves, which are not shown, are hereinafter referred to as pressure compensation valves 35, 36, etc. )have.
- the arm direction switching valve 34 is remotely operated by a pilot pressure from the operating device 37A.
- the operating device 37A includes the arm / swivel operating lever 27A described above and a pair of pressure reducing valves 38A that generate pilot pressure using the discharge pressure of the pilot pump as a source pressure in accordance with the operation of the operating lever 27A in the front-rear direction. , 38B, and a pair of pressure reducing valves (not shown) that generate pilot pressure using the discharge pressure of the pilot pump as a source pressure in response to the operation of the operation lever 27A in the left-right direction.
- the arm direction switching valve 34 is switched to the upper switching position in FIG.
- the pressure oil from the hydraulic pump 30 is supplied to the rod side of the arm hydraulic cylinder 23, the arm hydraulic cylinder 23 is shortened, and the arm 20 is rotated downward.
- the pilot pressure generated by the pressure reducing valve 38B in accordance with the operation amount is output to the pressure receiving portion on the lower side in FIG.
- the arm direction switching valve 34 is switched to the lower switching position in FIG.
- the boom direction switching valve 33 is remotely operated by the pilot pressure from the operation device 37B. More specifically, the operating device 37B includes the boom / bucket operating lever 27B described above and a pair of pressure reducing valves 38C that generate pilot pressure using the discharge pressure of the pilot pump as a base pressure in accordance with the operation of the operating lever 27B in the front-rear direction. , 38D, and a pair of pressure reducing valves (not shown) that generate pilot pressure using the discharge pressure of the pilot pump as a base pressure in response to the operation of the operation lever 27B in the left-right direction.
- the boom direction switching valve 33 is switched to the upper switching position in FIG.
- the pressure oil from the hydraulic pump 30 is supplied to the rod side of the boom hydraulic cylinder 22, the boom hydraulic cylinder 22 is shortened, and the boom 19 is rotated downward.
- the pilot pressure generated by the pressure reducing valve 38D according to the amount of operation is output to the pressure receiving portion on the lower side in FIG.
- the boom direction switching valve 33 is switched to the lower switching position in FIG.
- the configurations related to the left and right traveling hydraulic motors 13A and 13B, the blade hydraulic cylinder 15, the turning hydraulic motor 17, the swing hydraulic cylinder 18, and the bucket hydraulic cylinder 24 are also used for the boom described above.
- the configuration relating to driving of the hydraulic cylinder 22 and the arm hydraulic cylinder 23 is substantially the same. That is, the left and right traveling direction switching valves, the blade direction switching valve, the turning direction switching valve, the swing direction switching valve, and the bucket direction switching valve are respectively pilot pressures from corresponding operating devices (not shown). It is designed to be operated remotely.
- the direction switching valves 33 and 34 have load ports 33a and 34a for taking out the load pressure of the hydraulic actuator corresponding to the valve switching (however, the tank pressure becomes the tank pressure when the valve is neutral).
- the load ports 33a and 34a The plurality of load pressures Plmax (hereinafter referred to as the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc.) among the load pressures output from the plurality of load pressures are selected (seven in this embodiment).
- a load pressure shuttle valve 39 (only two are shown in FIG. 3).
- an LS differential pressure for detecting a load sensing differential pressure Pls (hereinafter referred to as an LS differential pressure Pls), which is a differential pressure between the discharge pressure Ps of the hydraulic pump 30 and the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc.
- a detection device 40 is provided.
- the LS differential pressure detection device 40 generates a pressure corresponding to the LS differential pressure Pls using the discharge pressure Ps of the hydraulic pump 30 as a source pressure, and the output of the differential pressure detection valve 41. And a pressure sensor 42 that measures the pressure (that is, the LS differential pressure Pls).
- the differential pressure detection valve 41 introduces the discharge pressure Ps of the hydraulic pump 30 to act on the pressure increase side, and introduces the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc. from the shuttle valve 39 to reduce the pressure side.
- a pressure receiving portion that introduces the output pressure of the differential pressure detection valve 41 itself and acts on the pressure reducing side. With such a structure, a pressure corresponding to the LS differential pressure Pls is generated and output.
- the pressure sensor 42 measures the output pressure of the differential pressure
- Each of the pressure compensation valves 35, 36, etc. introduces the upstream pressure of the corresponding directional switching valve and acts on the valve closing side, and the downstream pressure of the corresponding directional switching valve (specifically, the load port A pressure receiving portion that introduces an output pressure) to act on the valve opening side, and a pressure receiving portion that introduces the LS differential pressure Pls from the differential pressure detection valve 41 to act on the valve opening side.
- the differential pressure across the direction of all the directional control valves 33, 34 is controlled to become the LS differential pressure Pls.
- pressure oil is distributed at a ratio according to the opening area of the direction switching valve regardless of the load pressure of the hydraulic actuator. Yes.
- the regulator 31 includes a tilt actuator 43 that controls the tilt angle of the swash plate of the hydraulic pump 30 (that is, the displacement volume of the hydraulic pump 30), and the control pressure of the tilt actuator 43 using the discharge pressure of the hydraulic pump 30 as a source pressure. And an electromagnetic proportional valve 44 for generating
- a load sensing control device 45 (hereinafter referred to as LS control device 45) for controlling the electromagnetic proportional valve 44 and the bidirectional converter 28 of the regulator 31 is provided.
- the LS control device 45 variably controls the displacement volume of the hydraulic pump 30 via the regulator 31 so that the LS differential pressure Pls detected by the LS differential pressure detection device 40 becomes a preset target value Pgr.
- the rotational speed of the motor / generator 29 is variably controlled via the bidirectional converter 28.
- an input device 46 capable of changing the target value Pgr of the LS differential pressure is provided, and the operating speed of the hydraulic actuator can be changed by changing the target value Pgr of the LS differential pressure.
- FIG. 4 is a block diagram illustrating a functional configuration of the LS control device 45 together with related devices.
- the LS control device 45 includes a target value setting unit 47 for setting a target value Pgr of the LS differential pressure input from the input device 46, and an LS differential pressure Pls input from the pressure sensor 42 of the LS differential pressure detection device 40 and the target.
- a subtractor 48 that calculates a difference ⁇ Pls from the target value Pgr set by the value setting unit 47, and a first low-pass filter that applies a low-pass filter process of the cutoff frequency f1 to the difference ⁇ Pls calculated by the subtractor 48 49, a pump command calculation unit 50 that performs a predetermined calculation process on the difference ⁇ Pls ′ processed by the first low-pass filter unit 49 and outputs the generated control signal to the electromagnetic proportional valve 44 of the regulator 31, and a subtraction unit
- a second low-pass filter unit 51 that performs a low-pass filter process with a cut-off frequency f2 (where f2 ⁇ f1) on the difference ⁇ Pls calculated in 48;
- the processing of the low-pass filter units 49 and 51 will be specifically described with reference to FIGS. 5A to 5C.
- the temporal change of the difference ⁇ Pls calculated by the subtracting unit 48 assumes a case where the two frequencies fa and fb (where f1> fa> f2> fb) are dominant composite waveforms.
- the first low-pass filter unit 49 performs the process of removing the change component having the frequency f1 or higher with respect to the difference ⁇ Pls calculated by the subtraction unit 48
- the temporal change of the difference ⁇ Pls ′ after the process is as shown in FIG. 5B. Two frequencies fa and fb form a dominant composite waveform.
- the second low-pass filter unit 51 performs a process of removing the change component having the frequency f2 or higher with respect to the difference ⁇ Pls calculated by the subtracting unit 48, the temporal change of the processed difference ⁇ Pls ”is shown in FIG. 5C.
- the frequency fb becomes a dominant waveform.
- the pump command calculation unit 50 determines that the displacement difference ⁇ q of the hydraulic pump 30 is smaller than zero as the LS differential pressure difference ⁇ Pls ′ is greater than zero, and the LS differential pressure difference ⁇ Pls ′ is zero.
- a calculation table in which the difference ⁇ q of the displacement volume of the hydraulic pump 30 becomes larger than zero as it becomes smaller is stored in advance. Based on this calculation table, the displacement ⁇ qs ′ of the hydraulic pump 30 is calculated from the difference ⁇ Pls ′ of the LS differential pressure processed by the first low-pass filter unit 49, and this difference ⁇ q is calculated as the previous displacement volume command value.
- the electromagnetic proportional valve 44 is driven by a control signal from the pump command calculation unit 50, and generates and outputs a control pressure of the tilt actuator 43.
- a control signal from the pump command calculation unit 50 and generates and outputs a control pressure of the tilt actuator 43.
- the displacement volume of the hydraulic pump 30 is decreased, and the discharge flow rate of the hydraulic pump 30 is decreased.
- the displacement volume of the hydraulic pump 30 is increased to increase the discharge flow rate of the hydraulic pump 30.
- the motor / generator command calculation unit 52 makes the difference ⁇ N in the rotational speed of the motor / generator 29 smaller than zero as the LS differential pressure difference ⁇ Pls ′′ becomes larger than zero.
- a calculation table in which the difference ⁇ q in the rotational speed of the motor / generator 29 becomes larger than zero as the difference ⁇ Pls ′′ becomes smaller than zero is stored in advance. Then, based on this calculation table, the difference ⁇ N of the rotation speed of the motor / generator 29 is calculated from the difference ⁇ Pls ′′ of the LS differential pressure processed by the second low-pass filter unit 51, and this difference ⁇ N is calculated from the previous rotation speed.
- the motor / generator command calculation unit 52 stores in advance the upper limit value and the lower limit value of the rotational speed of the motor / generator 29, and the command value of the rotational speed described above is set to the upper limit value and the lower limit value. Limited by value. Thereby, the discharge pressure of the pilot pump, that is, the original pressure of the pilot pressure in the operating devices 37A, 37B, etc. is ensured.
- FIG. 6 is a block diagram showing the functional configuration of the bidirectional converter 28 together with related devices.
- the bidirectional converter 28 includes a step-up / step-down chopper 53, an AC / DC converter 54, and a controller 55.
- the step-up / step-down chopper 53 includes a booster circuit, a step-down circuit, a rectifier circuit, and a switch provided between these circuits.
- the controller 55 receives a control signal (that is, a command value for the rotational speed) from the LS control device 45 and controls the step-up / down chopper 53 and the AC / DC converter 54 in accordance with the command value for the rotational speed. ing.
- the controller 55 controls the motor / generator 29 when increasing or maintaining the number of rotations of the motor / generator 29 (in other words, when the difference LS Pl of the LS differential pressure is 0).
- a drive command for operating as an electric motor is output to the step-up / step-down chopper 53 and the AC / DC converter 54.
- the step-up / step-down chopper 53 boosts the voltage of the DC power from the power storage device 7 to the AC / DC converter 54.
- the AC / DC converter 54 generates AC power based on the DC power from the step-up / down chopper 53 and applies it to the motor / generator 29 to drive the motor / generator 29.
- the controller 55 When the rotational speed of the motor / generator 29 is decreased (in other words, when the difference ⁇ Pls ′′> 0 of the LS differential pressure), the motor / generator 29 is operated as a generator (regenerative brake). The regeneration command, and outputs it to the buck-53 and AC-DC converter 54.
- the AC / DC converter 54 converts the inertial force of the rotor of the motor / generator 29 into AC power, converts this AC power into DC power, and the step-up / down chopper 53 receives the AC / DC converter 54 from the AC / DC converter 54.
- the DC power voltage is boosted and supplied to the power storage device 7 to charge the power storage device 7.
- the bidirectional converter 28 is interposed between the commercial power source 56 and the power storage device 7 when a cable from the commercial power source 56 (external power source) is connected to the power supply port, for example.
- a charging switch (not shown) that can instruct the start / end of charging by an external power source while the motor / generator 29 is stopped is provided, and the controller 55 receives a charging start instruction signal from the charging switch.
- a charge command is output to the step-up / down chopper 53.
- the step-up / step-down chopper 53 converts the AC power from the commercial power source 56 into DC power, reduces the voltage, and supplies it to the power storage device 7 to charge the power storage device 7.
- the operation devices 37A, 37B and the like constitute a plurality of operation means for instructing the operations of the plurality of hydraulic actuators described in the claims.
- the regulator 31 constitutes pump control means for variably controlling the displacement of the hydraulic pump.
- the bidirectional converter 28 constitutes an electric / generator control means for variably controlling the rotational speed of the electric / generator.
- the LS differential pressure detection device 40 constitutes a differential pressure detection means for detecting a load sensing differential pressure.
- the LS control device 45 constitutes command control means for calculating command values to the pump control means and the motor / generator control means in accordance with changes in the required flow rate based on the operation command amounts from the plurality of operation means.
- the command value to the pump control means and the motor / generator control means is calculated according to the difference so that the load sensing differential pressure detected by the differential pressure detection means becomes a preset target value.
- the command control means is configured.
- the LS differential pressure Pls exceeds the target value Pgr.
- the LS control device 45 then displaces the hydraulic pump 30 via the regulator 31 so that the LS differential pressure Pls becomes the target value Pgr (in other words, the discharge flow rate of the hydraulic pump 30 that matches the required flow rate). And the rotational speed of the motor / generator 29 is reduced via the both converters 28.
- the bidirectional converter 28 performs regenerative control in which the inertial force of the rotor of the motor / generator 29 is converted into electric power to charge the power storage device 7. Therefore, the power storage device 7 can be charged, and the operation time of the mini excavator can be extended.
- the LS control device 45 includes the second low-pass filter unit 51 before the motor / generator command calculation unit 52 calculates the difference ⁇ Pls between the LS differential pressure Pls and the target value Pgr. A process of removing a change component having a frequency f2 or higher is performed on the difference ⁇ Pls.
- the LS control device 45 is configured such that the first low-pass filter unit 49 sets the difference ⁇ Pls before the pump command calculation unit 50 calculates the difference ⁇ Pls between the LS differential pressure Pls and the target value Pgr. On the other hand, a process of removing a change component having a frequency f1 or higher is performed.
- the LS differential pressure detection device 40 including the differential pressure detection valve 41 and the pressure sensor 42 is described as an example.
- the present invention is not limited to this. That is, for example, as in the first modification shown in FIG. 7, the LS differential pressure detection device 40 ⁇ / b> A configured by the differential pressure sensor 57 may be provided.
- the differential pressure sensor 57 introduces the discharge pressure Ps of the hydraulic pump 30 and introduces the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc. from the shuttle valve 39, and obtains the LS differential pressure ⁇ Pls, which is the differential pressure between them. This is measured and output to the LS control device 40 as an electrical signal. Also in such a modification, the same effect as the first embodiment can be obtained.
- an LS differential pressure detection device 40 ⁇ / b> B including a discharge pressure sensor 58, a maximum load pressure sensor 59, and a subtractor 60 may be provided.
- the discharge pressure sensor 58 introduces and measures the discharge pressure Ps of the hydraulic pump 30, and outputs this as an electrical signal.
- the maximum load pressure sensor 59 introduces and measures the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc. from the shuttle valve 39, and outputs this as an electrical signal.
- the subtractor 56 calculates an LS differential pressure Pls which is a differential pressure between the discharge pressure Ps of the hydraulic pump 30 input from the discharge pressure sensor 58 and the maximum load pressure Plmax input from the maximum load pressure sensor 59.
- the electric signal is output to the LS control device 40.
- the subtractor 56 may be configured not to be a part of the LS differential pressure detection device but to be a part of the LS control device. Also in such a modification, the same effect as the first embodiment can be obtained.
- the LS differential pressure detection device 40C has the same configuration as the LS differential pressure detection device 40B, and the hydraulic pressures of the discharge pressure sensor 58 and the maximum load pressure sensor 59 are the same.
- a diaphragm 61 may be provided on the introduction side. That is, by providing the diaphragm 61, the variation in the detection value of the sensor may be suppressed. Also in such a modification, the same effect as the first embodiment can be obtained.
- the pressure compensation valves 35A, 36A, etc. Pressure receiving section that introduces upstream pressure of the valve and acts on the valve closing side, and pressure receiving section that introduces downstream pressure (specifically, the output pressure of the load port) of the corresponding direction switching valve and acts on the valve opening side
- a second embodiment of the present invention will be described with reference to FIGS.
- the present embodiment is an embodiment that performs load sensing control having a control procedure different from that of the first embodiment.
- the same parts as those in the first embodiment and the modified example are given the same reference numerals, and description thereof will be omitted as appropriate.
- FIG. 10 is a schematic diagram showing the configuration of the electric drive device according to the present embodiment.
- the electric drive device includes the discharge pressure sensor 58 and the maximum load pressure sensor 59 as in the second or third modification.
- the LS control device 45A adds a preset target value Pgr of the LS differential pressure to the maximum load pressure Plmax detected by the maximum load pressure sensor 59 and the like of the plurality of hydraulic actuators 22, 23, etc.
- the target value Ps0 of the discharge pressure is set.
- the displacement volume of the hydraulic pump 30 is variably controlled via the regulator 31 so that the discharge pressure Ps of the hydraulic pump 30 detected by the discharge pressure sensor 58 becomes the target value Ps0.
- the rotational speed of the generator 29 is variably controlled.
- FIG. 11 is a block diagram illustrating the functional configuration of the LS control device 45A together with related devices.
- the LS control device 45A is set by a target value setting unit 47A that sets a target value Ps0 of the discharge pressure of the hydraulic pump 30, and a discharge pressure Ps and target value setting unit 47A of the hydraulic pump 30 that are input from the discharge pressure sensor 58.
- a subtractor 48A that calculates a difference ⁇ Ps from the target value Ps0, a first lowpass filter 49A that applies a lowpass filter process of the cutoff frequency f1 to the difference ⁇ Ps calculated by the subtractor 48A, and the first lowpass A predetermined calculation process is performed on the difference ⁇ Ps ′ processed by the filter unit 49A, and the generated control signal is output to the electromagnetic proportional valve 44 of the regulator 31, and the difference ⁇ Ps calculated by the subtraction unit 48A.
- a second low-pass filter unit 51A that performs a low-pass filter process with a cutoff frequency f2 (where f2 ⁇ f1), and the second low-pass filter Performs filter unit 51A has been treated with the difference DerutaPs "for a given operation process, and a motor-generator command calculation unit 52A outputs the generated control signal to the bidirectional converter 28.
- the target value setting unit 47A sets the target value Pgr of the LS differential pressure input from the input device 46. Further, the target value Pgr of the LS differential pressure is added to the maximum load pressure Plmax input from the maximum load pressure sensor 59, etc., and set as the target value Ps0 of the discharge pressure of the hydraulic pump 30. To do.
- the pump command calculation unit 50A determines that the displacement difference ⁇ q of the hydraulic pump 30 becomes smaller than zero as the discharge pressure difference ⁇ Ps ′ of the hydraulic pump 30 becomes larger than zero.
- the calculation table in which the displacement difference ⁇ q of the displacement of the hydraulic pump 30 becomes larger than zero as the difference ⁇ Ps ′ of the pressure becomes smaller than zero is stored in advance.
- the displacement volume difference ⁇ q is calculated from the discharge pressure difference ⁇ Ps ′ of the hydraulic pump 30 processed by the first low-pass filter section 49A, and this difference ⁇ q is calculated based on the previous displacement volume command value ( Or, for example, it may be added to the actual displacement value calculated based on the tilt angle of the swash plate of the hydraulic pump 30 detected by the tilt angle sensor) to obtain the command value of the current displacement volume.
- a corresponding control signal is generated and output to the electromagnetic proportional valve 44 of the regulator 31.
- the electromagnetic proportional valve 44 is driven by a control signal from the pump command calculation unit 50A, and generates and outputs a control pressure of the tilt actuator 43.
- a control signal from the pump command calculation unit 50A the displacement volume is decreased and the discharge flow rate is decreased.
- the displacement volume is increased to increase the discharge flow rate.
- the motor / generator command calculation unit 52A makes the difference ⁇ N in the rotational speed of the motor / generator 29 smaller than zero as the discharge pressure difference ⁇ Ps ′′ of the hydraulic pump 30 becomes larger than zero.
- a calculation table is stored in advance in which the difference ⁇ q in the rotational speed of the motor / generator 29 becomes larger than zero as the difference ⁇ Ps ′′ in the discharge pressure of the pump 30 becomes smaller than zero. Then, based on this calculation table, the difference ⁇ N of the rotational speed of the motor / generator 29 is calculated from the difference ⁇ Ps ′′ of the discharge pressure of the hydraulic pump 30 processed by the second low-pass filter 51A, and this difference ⁇ N is calculated from the previous difference ⁇ N.
- the motor / generator command calculation unit 52A stores in advance the upper limit value and the lower limit value of the rotational speed of the motor / generator 29, and the command value for the rotational speed described above is stored. Limited by upper and lower limits. Thereby, the discharge pressure of the pilot pump, that is, the original pressure of the pilot pressure in the operating devices 37A, 37B, etc. is ensured.
- the bidirectional converter 28 increases or maintains the rotation speed of the motor / generator 29 (specifically, the difference ⁇ Ps ′′ in the discharge pressure of the hydraulic pump 30 ⁇
- the electric motor / generator 29 is operated as an electric motor (when it is 0)
- the rotational speed of the electric motor / generator 29 is decreased (specifically, the difference ⁇ Ps ′′> 0 in the discharge pressure of the hydraulic pump 30).
- the motor / generator 29 is operated as a generator (regenerative brake).
- the discharge pressure sensor 58 constitutes a discharge pressure detecting means for detecting the discharge pressure of the hydraulic pump described in the claims.
- the maximum load pressure sensor 59 constitutes a maximum load pressure detecting means for detecting the maximum load pressure of a plurality of hydraulic actuators.
- the LS control device 45A constitutes command control means for calculating command values to the pump control means and the motor / generator control means in accordance with changes in the required flow rate based on the operation command amounts from each of the plurality of operation means.
- the target value for the discharge pressure of the hydraulic pump is set based on the maximum load pressure of the plurality of hydraulic actuators detected by the maximum load pressure detection means, and the discharge pressure of the hydraulic pump detected by the discharge pressure detection means is Command control means for calculating command values to the pump control means and the motor / generator control means according to the difference between them is configured so as to be the target value.
- the LS control device 45A causes the hydraulic pump 30 to pass through the regulator 31 so that the discharge pressure Ps of the hydraulic pump 30 becomes the target value Ps0 (in other words, the discharge flow rate of the hydraulic pump 30 corresponding to the required flow rate).
- the bidirectional converter 28 performs regenerative control in which the inertial force of the rotor of the motor / generator 29 is converted into electric power to charge the power storage device 7. Therefore, the power storage device 7 can be charged, and the operation time of the mini excavator can be extended.
- the LS control device 45A includes the second low-pass filter before the motor / generator command calculation unit 52A calculates the difference ⁇ Ps between the discharge pressure Ps of the hydraulic pump 30 and the target value Ps0.
- the unit 51A performs a process of removing the change component having the frequency f2 or higher with respect to the difference ⁇ Ps. And since this frequency f2 is made comparatively small, the sensitivity of the variable control of the rotation speed of the motor / generator 29 with respect to the fluctuation of the discharge pressure Ps of the hydraulic pump 30 (that is, the fluctuation of the LS differential pressure Pls) can be lowered. . Therefore, hunting can be suppressed.
- the LS control device 45A is configured such that the first low-pass filter unit 49A is configured so that the pump command calculation unit 50A calculates the difference ⁇ Ps between the discharge pressure Ps of the hydraulic pump 30 and the target value Ps0.
- a process of removing a change component having a frequency f1 or higher is performed on the difference ⁇ Ps.
- this frequency f1 is made comparatively large, the sensitivity of the variable control of the displacement volume of the hydraulic pump 30 with respect to the fluctuation
- the LS control device 45A applies, for example, the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc. input from the maximum load pressure sensor 59, for example.
- the target value setting unit 47A adds the target value Pgr of the LS differential pressure to the maximum load pressure Plmax of the plurality of hydraulic actuators 22, 23, etc. processed by the third low-pass filter unit, and supplies this to the discharge of the hydraulic pump 30. This is set as the pressure target value Ps0. In such a case, the same effect as described above can be obtained.
- the input device 46 can change the target value Pgr of the LS differential pressure
- the present invention is not limited to this. That is, for example, the target value Pgr for the LS differential pressure may be stored in the LS control device 45 as a preset fixed value. In this case, the same effect as described above can be obtained.
- FIGS. 1 and 2 A third embodiment of the present invention will be described with reference to FIGS.
- This embodiment is an embodiment that performs negative control. Note that in this embodiment, the same parts as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
- FIG. 12 is a schematic diagram illustrating the configuration of the electric drive device according to the present embodiment.
- a plurality of open center type directional control valves for controlling the direction and flow rate of the pressure oil supplied from the hydraulic pump 30 to the plurality of hydraulic actuators 22, 23, etc. (specifically, for the boom shown in FIG. 12).
- a control pressure generating throttle 63 is provided on the downstream side of the center bypass passage 62, and a control pressure sensor 64 for detecting the upstream pressure of the throttle 63 as the control pressure Pn is provided.
- a control pressure sensor 64 for detecting the upstream pressure of the throttle 63 as the control pressure Pn is provided.
- the control pressure Pn becomes relatively large.
- the center bypass flow path 62 is used. Therefore, the control pressure Pn is relatively small.
- a tilt angle sensor 65 for detecting the tilt angle ⁇ of the swash plate of the hydraulic pump 30 is provided. Further, the controller 55 of the bidirectional converter 28 calculates the rotation speed (actual value) N of the motor / generator 29 from the magnitude and phase of the drive current of the motor / generator 29.
- a negative control device 66 for controlling the electromagnetic proportional valve 44 and the bidirectional converter 28 of the regulator 31 is provided.
- This negative control device 66 is based on the tilt angle ⁇ of the swash plate of the hydraulic pump 30 detected by the tilt angle sensor 65 and the rotational speed N of the motor / generator 29 acquired by the bidirectional converter 28.
- a discharge flow rate Q of 30 is calculated, and a control pressure target value Pn0 corresponding to the discharge flow rate Q is set.
- the displacement of the hydraulic pump 30 is variably controlled via the regulator 31 according to the difference ⁇ Pn between the control pressure Pn detected by the control pressure sensor 64 and the target value Pn0, and the electric / power generation is performed via the bidirectional converter 28.
- the rotation speed of the machine 29 is variably controlled.
- FIG. 13 is a block diagram showing the functional configuration of the negative control device 66 together with related devices.
- the negative control device 66 includes a discharge flow rate calculation unit 67 for calculating the discharge flow rate Q of the hydraulic pump 30 and a target value for setting a target value Pn0 of the control pressure corresponding to the discharge flow rate Q calculated by the discharge flow rate calculation unit 67.
- the cut-off frequency f2 (provided that f is calculated with respect to the difference ⁇ Pn calculated by the pump command calculation unit 50B and the subtraction unit 48B output to the 31 electromagnetic proportional valve 44.
- a predetermined arithmetic process is performed on the second low-pass filter unit 51B that performs the low-pass filter process of ⁇ f1) and the difference ⁇ Pn ′′ processed by the second low-pass filter unit 51B, and the generated control signal is sent to the bidirectional converter 28. It has a motor / generator command calculator 52B for output.
- the discharge flow rate calculation unit 67 calculates the displacement volume of the hydraulic pump 30 from the tilt angle ⁇ of the swash plate of the hydraulic pump 30 detected by the tilt angle sensor 65, and the displacement volume of the hydraulic pump 30 and the bidirectional converter 28.
- the discharge flow rate Q of the hydraulic pump 30 is calculated by integrating the rotational speed N of the motor / generator 29 acquired in step (1).
- the target value setting unit 47B sets a control pressure target value Pn0 corresponding to the discharge flow rate Q of the hydraulic pump 30 calculated by the discharge flow rate calculation unit 67, for example, based on a calculation table as shown by a solid line in FIG. .
- This control pressure target value Pn0 is obtained when all the operating levers 27A, 27B, etc. are in the neutral position under the same discharge flow rate Q (in other words, when all the directional control valves 33A, 34A, etc. are in the neutral position).
- the control levers 27A, 27B, etc. are smaller by a predetermined value a (specifically, a predetermined value set in consideration of control responsiveness). From the control pressure Pn (indicated by a two-dot chain line in FIG. 14) when one of the valves is at the maximum operating position (in other words, when one of the direction switching valves 33A, 34A, etc. is at the switching position). It is getting bigger.
- the control pressure Pn and the target value Pn0 decrease while maintaining the relationship of the control pressure Pn> the target value Pn0, and finally, the discharge flow rate Q of the hydraulic pump 30 becomes the minimum value (more specifically, the hydraulic pump 30 The displacement volume of the motor / generator 29 becomes the minimum value, and the rotation speed N of the motor / generator 29 becomes the minimum value).
- the control pressure Pn ⁇ target value Pn0 that is, ⁇ Pn ⁇ 0
- variable control of the displacement of the hydraulic pump 30 and the variable control of the rotation speed of the motor / generator 29 are advanced in the direction of increasing the output flow rate Q of the hydraulic pump 30. That is, the control pressure target value Pn0 increases while maintaining the relationship of control pressure Pn ⁇ target value Pn0, and finally the discharge flow rate of the hydraulic pump 30 becomes the maximum value Q_max (more specifically, the hydraulic pump 30 The displacement volume becomes the maximum value q_max, and the rotation speed of the motor / generator 29 becomes the maximum value N_max).
- the pump command calculation unit 50B has a displacement difference ⁇ q of the hydraulic pump 30 that is smaller than zero as the control pressure difference ⁇ Pn ′ is greater than zero, and the control pressure difference ⁇ Pn ′ is smaller than zero.
- a calculation table in which the difference ⁇ q of the displacement volume of the hydraulic pump 30 becomes larger than zero is stored in advance.
- the difference ⁇ q of the displacement volume of the hydraulic pump 30 is calculated from the difference ⁇ Pn ′ of the control pressure processed by the first low-pass filter section 49B, and this difference ⁇ q is calculated as the previous displacement volume command value (
- the displacement of the hydraulic pump calculated by the discharge flow rate calculation unit 67 may be added to obtain a command value for the displacement of the current time, and a control signal corresponding to this is generated to the electromagnetic proportional valve 44 of the regulator 31. It is designed to output.
- the electromagnetic proportional valve 44 is driven by a control signal from the pump command calculation unit 50B, and generates and outputs a control pressure of the tilt actuator 43. Accordingly, for example, when the control pressure difference ⁇ Pn ′> 0, the displacement volume of the hydraulic pump 30 is decreased, and the discharge flow rate of the hydraulic pump 30 is decreased. On the other hand, for example, when the control pressure difference ⁇ Pn ′ ⁇ 0, the displacement volume of the hydraulic pump 30 is increased to increase the discharge flow rate of the hydraulic pump 30.
- the motor / generator command calculation unit 52B determines that the difference ⁇ N in the number of revolutions of the motor / generator 29 becomes smaller than zero as the control pressure difference ⁇ Pn ′′ becomes larger than zero, and the control pressure difference ⁇ Pn ′′.
- a calculation table in which the difference ⁇ q in the rotation speed of the motor / generator 29 becomes larger than zero as is smaller than zero is stored in advance. Then, based on this calculation table, the difference ⁇ N in the rotational speed of the motor / generator 29 is calculated from the control pressure difference ⁇ Pn ′′ processed in the second low-pass filter section 51B, and this difference ⁇ N is calculated as the previous rotational speed command.
- This value is added to the value (or may be the actual value of the rotational speed acquired by the bidirectional converter 28) to obtain a command value for the current rotational speed, and a control signal corresponding to this is generated and output to the bidirectional converter 28 It is like that.
- the motor / generator command calculation unit 52B stores in advance the upper limit value and the lower limit value of the rotational speed of the motor / generator 29, and sets the above-described rotational speed command value as the upper limit value and Limited by the lower limit. Thereby, the discharge pressure of the pilot pump, that is, the original pressure of the pilot pressure in the operating devices 37A, 37B, etc. is ensured.
- the bidirectional converter 28 increases or maintains the rotational speed of the motor / generator 29 (specifically, when the control pressure difference ⁇ Pn ′′ ⁇ 0).
- the motor / generator 29 is operated as an electric motor, while the motor / generator 29 is operated when the rotation speed of the motor / generator 29 is decreased (specifically, when the control pressure difference ⁇ Pn ′′> 0). Is operated as a generator (regenerative brake).
- control pressure sensor 64 is an upstream pressure of the throttle that changes based on a change in the switching amount of at least one of a plurality of directional control valves that switch on the upstream side of the throttle.
- a control pressure detecting means for detecting as a control pressure is configured.
- the tilt angle sensor 65 constitutes a tilt angle detecting means for detecting the tilt angle of the hydraulic pump.
- the bidirectional converter 28 constitutes a rotational speed acquisition means for acquiring the rotational speed of the motor / generator.
- the negative control device 66 constitutes command control means for calculating command values to the pump control means and the motor / generator control means in accordance with changes in the required flow rate based on the operation command amounts from each of the plurality of operation means. To do. Further, the negative control device 66 calculates the discharge flow rate of the hydraulic pump based on the tilt angle of the hydraulic pump detected by the tilt angle detection means and the motor / generator rotation speed acquired by the rotation speed acquisition means.
- a target value for the control pressure is set based on the discharge flow rate calculating means and the discharge flow rate of the hydraulic pump calculated by the discharge flow rate calculating means, and according to the difference between the control pressure detected by the control pressure detecting means and the target value Command control means for calculating command values to the pump control means and the motor / generator control means is configured.
- the corresponding directional control valve is returned from the switching position to the neutral position, and the required flow rate decreases.
- the control pressure Pn increases and exceeds the target value Pn0 corresponding to the discharge flow rate Q of the hydraulic pump.
- the negative control device 66 finally reduces the displacement volume of the hydraulic pump 30 through the regulator 31 to the minimum value q_min according to the difference between the control pressure Pn and the target value Pn0, and the electric power is supplied through the bi-directional converter 28.
- the rotational speed of the generator 29 is finally reduced to the minimum value N_min (in other words, the discharge flow rate of the hydraulic pump 30 commensurate with the required flow rate).
- the bidirectional converter 28 performs regenerative control in which the inertial force of the rotor of the motor / generator 29 is converted into electric power to charge the power storage device 7. Therefore, the power storage device 7 can be charged, and the operation time of the mini excavator can be extended.
- the negative control device 66 determines that the second low-pass filter unit 51B has a difference before the motor / generator command calculation unit 52B calculates the difference ⁇ Pn between the control pressure Pn and the target value Pn0. A process of removing a change component having a frequency f2 or higher is performed on ⁇ Pn. And since this frequency f2 is made comparatively small, the sensitivity of the variable control of the rotation speed of the motor / generator 29 with respect to the fluctuation of the control pressure Pn can be lowered.
- the negative control device 66 is configured such that the first low-pass filter unit 49B detects the difference ⁇ Pn before the pump command calculation unit 50B calculates the difference ⁇ Pn between the control pressure Pn and the target value Pn0.
- the process of removing the change component having the frequency f1 or higher is performed.
- this frequency f1 is made comparatively large, the sensitivity of the variable control of the displacement volume of the hydraulic pump 30 with respect to the fluctuation
- FIGS. A fourth embodiment of the present invention will be described with reference to FIGS.
- This embodiment is an embodiment that performs positive control. Note that in this embodiment, the same parts as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
- FIG. 15 is a schematic diagram illustrating the configuration of the electric drive device according to the present embodiment.
- a tilt angle sensor 65 for detecting the tilt angle ⁇ of the swash plate of the hydraulic pump 30 is provided as in the third embodiment. Further, the controller 55 of the bidirectional converter 28 calculates the rotation speed (actual value) N of the motor / generator 29 from the magnitude and phase of the drive current of the motor / generator 29.
- a pilot pressure shuttle valve 68 (only four are shown in FIG. 15) is provided, and a pilot pressure sensor 69 for detecting the output pressure (that is, the maximum pilot pressure Pp) of the final stage shuttle valve 68 is provided.
- a positive control device 70 for controlling the electromagnetic proportional valve 44 and the bidirectional converter 28 of the regulator 31 is provided.
- the positive control device 70 is a hydraulic pump based on the tilt angle ⁇ of the swash plate of the hydraulic pump 30 detected by the tilt angle sensor 65 and the rotational speed N of the motor / generator 29 acquired by the bidirectional converter 28.
- a discharge flow rate Q of 30 is calculated.
- the required flow rate Qref is set based on the maximum pilot pressure Pp detected by the pilot pressure sensor 69, and the displacement volume of the hydraulic pump 30 through the regulator 31 so that the discharge flow rate Q of the hydraulic pump 30 becomes the required flow rate Qref.
- the rotational speed of the motor / generator 29 are variably controlled via the bidirectional converter 28.
- FIG. 16 is a block diagram illustrating a functional configuration of the positive control device 70 together with related devices.
- the positive control device 70 includes a target value setting unit 47C that sets a required flow rate (in other words, a target value of the discharge flow rate) Qref based on the maximum pilot pressure Pp detected by the pilot pressure sensor 69, and a discharge flow rate of the hydraulic pump 30.
- a discharge flow rate calculation unit 67 for calculating Q a subtraction unit 48C for calculating a difference ⁇ Q between the discharge flow rate Q calculated by the discharge flow rate calculation unit 67 and the required flow rate Qref set by the target value setting unit 47C, A first low-pass filter unit 49C that performs a low-pass filter process with a cutoff frequency f1 on the difference ⁇ Q calculated by the subtracting unit 48C, and a predetermined calculation process for the difference ⁇ Q ′ processed by the first low-pass filter unit 49C.
- the difference calculated by the pump command calculation unit 50C that outputs the generated control signal to the electromagnetic proportional valve 44 of the regulator 31 and the subtraction unit 48C.
- a second low-pass filter unit 51C that performs low-pass filter processing of the cut-off frequency f2 (where f2 ⁇ f1) is applied to the minute ⁇ Q, and a predetermined calculation process is performed on the difference ⁇ Q ′′ processed by the second low-pass filter unit 51C.
- a motor / generator command calculator 52C that outputs the generated control signal to the bidirectional converter 28.
- the target value setting unit 47C sets a required flow rate Qref corresponding to the maximum pilot pressure Pp based on, for example, a calculation table as shown in FIG.
- This required flow rate Qref is assumed when all the operating levers are in the maximum operating position (that is, when the maximum pilot pressure detected by the pilot pressure sensor 69 is output to all the directional control valves 33A, 34A, etc.). This is equivalent to the sum of the opening area of the direction switching valves 33A, 34A and the like and the differential pressure before and after.
- the pump command calculation unit 50C has a displacement volume difference ⁇ q of the hydraulic pump 30 that is smaller than zero as the discharge flow difference ⁇ Q ′ of the hydraulic pump 30 becomes larger than zero.
- the calculation table in which the displacement difference ⁇ q of the displacement of the hydraulic pump 30 becomes larger than zero as the difference ⁇ Q ′ becomes smaller than zero is stored in advance.
- the displacement volume difference ⁇ q is calculated from the difference ⁇ Q ′ of the discharge flow rate of the hydraulic pump 30 processed by the first low-pass filter section 49C, and this difference ⁇ q is calculated based on the previous displacement volume command value (
- the displacement volume of the hydraulic pump 30 calculated by the discharge flow rate calculation unit 67 may be added to obtain a command value for the displacement volume at this time, and a control signal corresponding to this is generated to generate an electromagnetic proportional valve 44 of the regulator 31. To output.
- the electromagnetic proportional valve 44 is driven by a control signal from the pump command calculation unit 50C to generate and output the control pressure of the tilt actuator 43.
- the displacement volume is decreased to decrease the discharge flow rate.
- the displacement volume is increased to increase the discharge flow rate.
- the motor / generator command calculating unit 52C has a difference ⁇ N in the number of revolutions of the motor / generator 29 that is smaller than zero as the difference ⁇ Q ′′ in the discharge flow rate of the hydraulic pump 30 is larger than zero.
- a calculation table in which the difference ⁇ q in the rotational speed of the motor / generator 29 becomes larger than zero as the difference ⁇ Q ′′ in the discharge flow rate of the pump 30 becomes smaller than zero is stored in advance.
- the difference ⁇ N ”in the rotational speed of the motor / generator 29 is calculated from the difference ⁇ Q ′′ in the discharge flow rate of the hydraulic pump 30 processed by the second low-pass filter 51C, and this difference ⁇ N is calculated from the previous time. This is added to the rotational speed command value (or the actual rotational speed value acquired by the bidirectional converter 28) to obtain the current rotational speed command value, and a control signal corresponding to this is generated to generate the bidirectional converter. 28 is output.
- the motor / generator command calculation unit 52C stores in advance the upper limit value and the lower limit value of the rotation speed of the motor / generator 29, and sets the above-described rotation speed command value as the upper limit value and Limited by the lower limit. Thereby, the discharge pressure of the pilot pump, that is, the original pressure of the pilot pressure in the operating devices 37A, 37B, etc. is ensured.
- the bidirectional converter 28 increases or maintains the rotational speed of the motor / generator 29 (specifically, the difference ⁇ Q ′′ ⁇ 0 in the discharge flow rate of the hydraulic pump 30).
- the motor / generator 29 is operated as an electric motor, on the other hand, when the rotational speed of the motor / generator 29 is decreased (specifically, when the difference ⁇ Q ′′> 0 in the discharge flow rate of the hydraulic pump 30).
- the motor / generator 29 is operated as a generator (regenerative brake).
- the pilot pressure sensor 69 constitutes a maximum operation amount detection means for detecting the maximum operation amount of the plurality of operation means described in the claims.
- the positive control device 70 constitutes command control means for calculating command values to the pump control means and the motor / generator control means in accordance with changes in the required flow rate based on the operation command amounts from the plurality of operation means. To do. Further, the positive control device 70 calculates the discharge flow rate of the hydraulic pump based on the tilt angle of the hydraulic pump detected by the tilt angle detection means and the motor / generator rotation speed acquired by the rotation speed acquisition means.
- the required flow rate is set based on the maximum operation amount of the plurality of operation means detected by the discharge flow rate calculation means and the maximum operation amount detection means, and the discharge flow rate of the hydraulic pump calculated by the discharge flow rate calculation means becomes the required flow rate.
- the command control means which calculates the command value to a pump control means and an electric motor / generator control means according to those differences is comprised.
- the positive control device 70 reduces the displacement volume of the hydraulic pump 30 via the regulator 31 so that the discharge flow rate Q of the hydraulic pump 30 becomes the required flow rate Qref, and the electric / generator 29 via the bi-directional converter 28. Decrease the rotation speed.
- the bidirectional converter 28 performs regenerative control in which the inertial force of the rotor of the motor / generator 29 is converted into electric power to charge the power storage device 7. Therefore, the power storage device 7 can be charged, and the operation time of the mini excavator can be extended.
- the positive controller 70 includes the second low-pass filter before the motor / generator command calculator 52C calculates the difference ⁇ Q between the discharge flow rate Q of the hydraulic pump 30 and the required flow rate Qref.
- the unit 51C performs a process of removing the change component having the frequency f2 or higher with respect to the difference ⁇ Q. And since this frequency f2 is made comparatively small, the sensitivity of the variable control of the rotation speed of the motor / generator 29 with respect to fluctuations in the required flow rate Qref can be lowered. Therefore, hunting can be suppressed.
- the positive control device 70 includes the first low-pass filter unit 49C before the pump command calculation unit 50C calculates the difference ⁇ Q between the discharge flow rate Q of the hydraulic pump 30 and the required flow rate Qref.
- a process of removing a change component having a frequency f1 or higher is performed on the difference ⁇ Q.
- this frequency f1 is made comparatively large, the sensitivity of the variable control of the displacement volume of the hydraulic pump 30 with respect to the fluctuation
- an input device capable of inputting a proportional coefficient for changing the operating speed of the hydraulic actuator is provided to set a target value of the positive control device.
- the unit may add and correct the proportionality coefficient input from the input device to the required flow rate Qref. In such a case, the same effect as described above can be obtained.
- a hydraulic pilot type operation device 37A, 37B that outputs a pilot pressure corresponding to the operation position of the operation lever is adopted as the plurality of operation means.
- an electric lever type operation device that outputs an electric operation signal corresponding to the operation position of the operation lever may be employed.
- the maximum operation amount detection means is selected from among the electric operation signals output from the operation device. What is necessary is just to provide the calculating part to take out. In such a case, the same effect as described above can be obtained.
- the bidirectional converter 28 supplies the electric power from the power storage device 7 to the motor / generator 29 to drive the motor / generator 29.
- a second control mode in which the electric power from the external power source is supplied to the power storage device 7 to charge the power storage device 7, and the rotational speed of the motor / generator 29 can be selected during the first control mode.
- the case where regenerative control is performed when decreasing is described as an example, but is not limited thereto.
- the third control mode in which electric power from the external power source is supplied to the motor / generator 29 to drive the motor / generator 29, and from the external power source
- a fourth control mode for supplying electric power to the motor / generator 29 and the power storage device 7 to drive the motor / generator 29 and to charge the power storage device 7 is set according to the operation of a mode selection switch (not shown). You may comprise so that it can perform selectively. Then, during the third control mode or the fourth control mode, when the rotational speed of the motor / generator 29 is decreased, the regeneration control may be performed while temporarily interrupting the power supply from the external power source. In such a case, the same effect as described above can be obtained.
- a mini excavator has been described as an example of an application of the present invention.
- the present invention is not limited to this, and the present invention may be applied to a medium-sized or large-sized hydraulic excavator (a hydraulic excavator having an operating mass of 6 tons or more). Further, the present invention is not limited to the hydraulic excavator, and may be applied to other construction machines such as a hydraulic crane.
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Abstract
Description
13A 走行用油圧モータ
13B 走行用油圧モータ
15 ブレード用油圧シリンダ
17 旋回用油圧モータ
18 スイング用油圧シリンダ
22 ブーム用油圧シリンダ
23 アーム用油圧シリンダ
24 バケット用油圧シリンダ
28 双方向コンバータ(電動・発電機制御手段、回転数取得手段)
29 電動・発電機
30 油圧ポンプ
31 レギュレータ(ポンプ制御手段)
33,33A ブーム用方向切換弁
34,34A アーム用方向切換弁
35,35A ブーム用圧力補償弁
36,36A アーム用圧力補償弁
37A 操作装置(操作手段)
37B 操作装置(操作手段)
40,40A,40B,40C LS差圧検出装置(差圧検出手段)
45,45A ロードセンシング制御装置(指令制御手段)
48,48A,48B,48C 減算部(減算手段)
49,49A,49B,49C 第1ローパスフィルタ部(第1のローパスフィルタ手段)
50,50A,50B,50C ポンプ指令演算部(第1の指令演算手段)
51,51A,51B,51C 第2ローパスフィルタ部(第2のローパスフィルタ手段)
52,52A,52B,52C 電動・発電機指令演算部(第2の指令演算手段)
58 吐出圧センサ(吐出圧検出手段)
59 最高負荷圧センサ(最高負荷圧検出手段)
62 センタバイパス流路
63 絞り
64 制御圧センサ(制御圧検出手段)
65 傾転角センサ(傾転角検出手段)
66 ネガティブ制御装置(指令制御手段)
67 吐出流量演算部(吐出流量演算手段)
69 パイロット圧センサ(最大操作量検出手段)
70 ポジティブ制御装置(指令制御手段)
Claims (9)
- 蓄電装置(7)と、
前記蓄電装置(7)との間で電力の授受を行う電動・発電機(29)と、
前記電動・発電機(29)によって駆動する可変容量型の油圧ポンプ(30)と、
複数の油圧アクチュエータ(22,23)と、
前記複数の油圧アクチュエータ(22,23)の動作を指示する複数の操作手段(37A,37B)と、
前記複数の操作手段(37A,37B)の操作方向及び操作量に応じて、前記油圧ポンプ(30)から前記複数の油圧アクチュエータ(22,23)へ供給する圧油の方向及び流量をそれぞれ制御する複数の方向切換弁(33,34;33A,34A)とを備えた建設機械の電動駆動装置において、
前記油圧ポンプ(30)の押しのけ容積を可変制御するポンプ制御手段(31)と、
前記電動・発電機(29)の回転数を可変制御する電動・発電機制御手段(28)と、
前記複数の操作手段(37A,37B)のそれぞれからの操作指令量に基づく要求流量の変化に応じて前記ポンプ制御手段(31)及び前記電動・発電機制御手段(28)への指令値を演算する指令制御手段(45;45A;66;70)とを備え、
前記電動・発電機制御手段(28)は、前記要求流量の減少に応じて前記電動・発電機(29)の回転数を減少させるときに、前記電動・発電機(29)の回転子の慣性力を電力に変換して前記蓄電装置(7)を充電する回生制御を行うことを特徴とする建設機械の電動駆動装置。 - 請求項1記載の建設機械の電動駆動装置において、
前記複数の方向切換弁(33,34)のそれぞれの前後差圧が、前記油圧ポンプ(30)の吐出圧と前記複数の油圧アクチュエータ(22,23)の最高負荷圧との差圧であるロードセンシング差圧となるように制御する複数の圧力補償弁(35,36;35A,36A)と、
前記ロードセンシング差圧を検出する差圧検出手段(40;40A;40B;40C)とを備え、
前記指令制御手段(45)は、前記差圧検出手段(40;40A;40B;40C)で検出されたロードセンシング差圧が予め設定された目標値となるように、それらの差分に応じて前記ポンプ制御手段(31)及び前記電動・発電機制御手段(28)への指令値を演算しており、
前記電動・発電機制御手段(28)は、前記ロードセンシング差圧が前記目標値を上回って前記電動・発電機(29)の回転数を減少させるときに、前記電動・発電機(29)の回転子の慣性力を電力に変換して前記蓄電装置(7)を充電する回生制御を行うことを特徴とする建設機械の電動駆動装置。 - 請求項2記載の建設機械の電動駆動装置において、
前記指令制御手段(45)は、
前記差圧検出手段(40;40A;40B;40C)で検出されたロードセンシング差圧と予め設定された目標値との差分を演算する減算手段(48)と、
前記減算手段(48)で算出された差分に対し、予め設定された第1の周波数以上の変化成分を除去する処理を行う第1のローパスフィルタ手段(49)と、
前記第1のローパスフィルタ手段(49)で処理された差分に応じて前記ポンプ制御手段(31)への指令値を演算する第1の指令演算手段(50)と、
前記減算手段(48)で算出された差分に対し、前記第1の周波数より小さくなるように予め設定された第2の周波数以上の変化成分を除去する処理を行う第2のローパスフィルタ手段(51)と、
前記第2のローパスフィルタ手段(51)で処理された差分に応じて前記電動・発電機制御手段(28)への指令値を演算する第2の指令演算手段(52)とを有することを特徴とする建設機械の電動駆動装置。 - 請求項1記載の建設機械の電動駆動装置において、
前記複数の方向切換弁(33,34)のそれぞれの前後差圧が、前記油圧ポンプ(30)の吐出圧と前記複数の油圧アクチュエータ(22,23)の最高負荷圧との差圧であるロードセンシング差圧となるように制御する複数の圧力補償弁(35A,36A)と、
前記油圧ポンプ(30)の吐出圧を検出する吐出圧検出手段(58)と、
前記複数の油圧アクチュエータ(22,23)の最高負荷圧を検出する最高負荷圧検出手段(59)とを備え、
前記指令制御手段(45A)は、前記最高負荷圧検出手段(59)で検出された前記複数の油圧アクチュエータ(22,23)の最高負荷圧に基づいて前記油圧ポンプ(30)の吐出圧に対する目標値を設定し、前記吐出圧検出手段(58)で検出された前記油圧ポンプ(30)の吐出圧が前記目標値となるように、それらの差分に応じて前記ポンプ制御手段(31)及び前記電動・発電機制御手段(28)への指令値を演算しており、
前記電動・発電機制御手段(28)は、前記油圧ポンプ(30)の吐出圧が前記目標値を上回って前記電動・発電機(29)の回転数を減少させるときに、前記電動・発電機(29)の回転子の慣性力を電力に変換して前記蓄電装置(7)を充電する回生制御を行うことを特徴とする建設機械の電動駆動装置。 - 請求項4記載の建設機械の電動駆動装置において、
前記指令制御手段(45A)は、
前記最高負荷圧検出手段(59)で検出された前記複数の油圧アクチュエータ(22,23)の最高負荷圧に基づいて前記油圧ポンプ(30)の吐出圧に対する目標値を設定する目標値設定手段(47A)と、
前記吐出圧検出手段(58)で検出された前記油圧ポンプ(30)の吐出圧と前記目標値設定手段(47A)で設定された目標値との差分を演算する減算手段(48A)と、
前記減算手段(48A)で算出された差分に対し、予め設定された第1の周波数以上の変化成分を除去する処理を行う第1のローパスフィルタ手段(49A)と、
前記第1のローパスフィルタ手段(49A)で処理された差分に応じて前記ポンプ制御手段(31)への指令値を演算する第1の指令演算手段(50A)と、
前記減算手段(48A)で算出された差分に対し、前記第1の周波数より小さくなるように予め設定された第2の周波数以上の変化成分を除去する処理を行う第2のローパスフィルタ手段(51A)と、
前記第2のローパスフィルタ手段(51A)で処理された差分に応じて前記電動・発電機制御手段(28)への指令値を演算する第2の指令演算手段(52A)とを有することを特徴とする建設機械の電動駆動装置。 - 請求項1記載の建設機械の電動駆動装置において、
前記複数の方向切換弁(33A,34A)は、オープンセンタ型であり、
前記複数の方向切換弁(33A,34A)のセンタバイパス流路の下流側に設けられた絞り(63)と、
前記絞り(63)の上流側で切換わる複数の方向切換弁(33A,34A)のうちの少なくとも1つの切換量の変化に基づき変化する、前記絞り(63)の上流側圧力を制御圧として検出する制御圧検出手段(64)と、
前記油圧ポンプ(30)の傾転角を検出する傾転角検出手段(65)と、
前記電動・発電機(29)の回転数を取得する回転数取得手段(28)と、
前記傾転角検出手段(65)で検出された前記油圧ポンプ(30)の傾転角及び前記回転数取得手段(28)で取得された前記電動・発電機(29)の回転数に基づいて前記油圧ポンプ(30)の吐出流量を演算する吐出流量演算手段(67)とを備え、
前記指令制御手段(66)は、前記吐出流量演算手段(67)で算出された前記油圧ポンプ(30)の吐出流量に基づいて前記制御圧に対する目標値を設定し、前記制御圧検出手段(64)で検出された制御圧と前記目標値との差分に応じて前記ポンプ制御手段(31)及び前記電動・発電機制御手段(28)への指令値を演算しており、
前記電動・発電機制御手段(28)は、前記制御圧が前記目標値を上回って前記電動・発電機(29)の回転数を減少させるときに、前記電動・発電機(29)の回転子の慣性力を電力に変換して前記蓄電装置(7)を充電する回生制御を行うことを特徴とする建設機械の電動駆動装置。 - 請求項6記載の建設機械の電動駆動装置において、
前記指令制御手段(66)は、
前記吐出流量演算手段(67)で算出された前記油圧ポンプ(30)の吐出流量に基づいて制御圧に対する目標値を設定する目標値設定手段(47B)と、
前記制御圧検出手段(64)で検出された制御圧と前記目標値設定手段(47B)で設定された目標値との差分を演算する減算手段(48B)と、
前記減算手段(48B)で算出された差分に対し、予め設定された第1の周波数以上の変化成分を除去する処理を行う第1のローパスフィルタ手段(49B)と、
前記第1のローパスフィルタ手段(49B)で処理された差分に応じて前記ポンプ制御手段(31)への指令値を演算する第1の指令演算手段(50B)と、
前記減算手段(48B)で算出された差分に対し、前記第1の周波数より小さくなるように予め設定された第2の周波数以上の変化成分を除去する処理を行う第2のローパスフィルタ手段(51B)と、
前記第2のローパスフィルタ手段(51B)で処理された差分に応じて前記電動・発電機制御手段(28)への指令値を演算する第2の指令演算手段(52B)とを有することを特徴とする建設機械の電動駆動装置。 - 請求項1記載の建設機械の電動駆動装置において、
前記複数の操作手段(37A,37B)の最大操作量を検出する最大操作量検出手段(69)と、
前記油圧ポンプ(30)の傾転角を検出する傾転角検出手段(65)と、
前記電動・発電機(29)の回転数を検出する回転数取得手段(28)と、
前記傾転角検出手段(65)で検出された前記油圧ポンプ(30)の傾転角及び前記回転数取得手段(28)で検出された前記電動・発電機(29)の回転数に基づいて前記油圧ポンプ(30)の吐出流量を演算する吐出流量演算手段(67)とを備え、
前記指令制御手段(70)は、前記最大操作量検出手段(69)で検出された前記複数の操作手段(37A,37B)の最大操作量に基づいて要求流量を設定し、前記吐出流量演算手段(67)で算出された前記油圧ポンプ(30)の吐出流量が前記要求流量となるように、それらの差分に応じて前記ポンプ制御手段(31)及び前記電動・発電機制御手段(28)への指令値を演算しており、
前記電動・発電機制御手段(28)は、前記油圧ポンプ(30)の吐出流量が前記要求流量を上回って前記電動・発電機(29)の回転数を減少させるときに、前記電動・発電機(29)の回転子の慣性力を電力に変換して前記蓄電装置(7)を充電する回生制御を行うことを特徴とする建設機械の電動駆動装置。 - 請求項8記載の建設機械の電動駆動装置において、
前記指令制御手段(70)は、
前記最大操作量検出手段(69)で検出された前記複数の操作手段(37A,37B)の最大操作量に基づいて要求流量を設定する要求流量設定手段(47C)と、
前記吐出流量演算手段(67)で算出された前記油圧ポンプ(30)の吐出流量と前記要求流量設定手段(47)で設定された要求流量との差分を演算する減算手段(48C)と、
前記減算手段(48C)で算出された差分に対し、予め設定された第1の周波数以上の変化成分を除去する処理を行う第1のローパスフィルタ手段(49C)と、
前記第1のローパスフィルタ手段(49C)で処理された差分に応じて前記ポンプ制御手段(31)への指令値を演算する第1の指令演算手段(50C)と、
前記減算手段(48C)で算出された差分に対し、前記第1の周波数より小さくなるように予め設定された第2の周波数以上の変化成分を除去する処理を行う第2のローパスフィルタ手段(51C)と、
前記第2のローパスフィルタ手段(51C)で処理された差分に応じて前記電動・発電機制御手段(28)への指令値を演算する第2の指令演算手段(52C)とを有することを特徴とする建設機械の電動駆動装置。
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KR1020137030751A KR101845122B1 (ko) | 2011-05-25 | 2012-05-10 | 건설 기계의 전동 구동 장치 |
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