JP2009052339A - Operation control method of hybrid type working machine and working machine using the same method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation control method of a hybrid type working machine which carries out temperature management so as not to disable respective electric circuit parts at an electric drive device part side due to temperature increase in them in the hybrid type working machine, and also to provide a device using the same method. <P>SOLUTION: In the hybrid type working machine comprising an electric drive device part ED and a hydraulic drive device part HD which rotatingly drive a turning inertia body 60, temperature sensors S1, S2, and S3 are arranged at an electric storage device 90, an inverter/converter 102, and a motor-generator unit 70A of the electric drive device part, respectively. When any one of detected temperatures θ1-θ3 from the respective temperature sensors exceeds a preset temperature, a controller CU reduces the present ratio of a torque command value Tem (Teg) to the electric drive device part with respect to a torque command value Tm to the hydraulic drive device part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drive device for a construction work machine such as a hydraulic excavator, in particular, a drive using a hydraulic pump driven by an engine or other prime mover as a hydraulic supply source and a drive system using a motor as a drive source. Control of a hybrid work machine having a function of converting kinetic energy of the inertial body into electrical energy when braking the inertial body that forms part of the structure of the work machine Regarding the method.

  In a construction work machine such as a hydraulic excavator (hereinafter simply referred to as a work machine), various measures for improving a work environment such as exhaust gas and noise have been proposed in recent years as a hybrid type.

  In a working machine such as a hydraulic excavator, in order to collect and reuse inertial energy when driving (including braking) a revolving body having large inertia, a method of electrically driving the revolving body, electric drive and hydraulic drive, A method of applying in combination is shown. However, the work machine is usually used in a poor environment, and it is difficult to control the environmental temperature, particularly outdoors. Therefore, the drive device is often placed in a very severe temperature environment.

  By the way, as a drive source for operating a structure such as an inertial body of a work machine, a hydraulic drive device has a lot of application results and has sufficient reliability. However, an electric drive device has an electric resistance and electric motor accompanying electric energy transmission. It always has an element of heat generation due to mechanical loss of the rotating body that forms part of the driving device.

  In the hydraulic drive device, the fluid transmits energy and heat, so that the generated heat can be dissipated by cooling the fluid. On the other hand, in the electric drive device, the device itself needs to be cooled. However, work machines generally have a small space for installing an electric or hydraulic drive device, and it is difficult to reduce the environmental temperature to such an extent that safety is always maintained when the work machine is continuously operated. There is a circumstance.

  On the other hand, the drive control system of a hybrid type work machine is roughly divided into two systems, a series and a parallel system. The series system is a working machine in which a generator is driven once by an engine, an electric motor is driven by the electric power generated by the generator, and a hydraulic pump is driven by the electric motor. Further, surplus electric power from the generator is transferred to a battery. Or the like, and the electric motor is driven by the stored battery power as required. FIG. 12 shows a block configuration of a drive system and a control system of this hydraulic excavator. (Patent Document 1)

  In the parallel system, a hydraulic pump and a generator are mechanically driven simultaneously by an engine, and further, the generator is driven by a battery as an electric motor.

  In FIG. 12, a solid line arrow indicates an electric drive system, and a dotted line arrow indicates a hydraulic drive system.

  An inverter 23 is provided between the generator 21 and the electric motor 24 and the battery 22. The inverter 23 converts AC power generated by the generator 21 into DC and stores it in the battery 22 (charging action). The stored power of the battery 22 is converted into alternating current and supplied to the motor 24 (discharge action).

  The inverter 23 is provided with a switching means (not shown), and the charging / discharging action is switched by an operator's operation or automatically according to the load state.

  The hydraulic fluid of the hydraulic pump 25 driven by the electric motor 24 is supplied to each hydraulic actuator (for turning and traveling hydraulic motors 26, 27, and 28, and for booms, arms and buckets) via a control valve 32 provided in each hydraulic actuator. The control valve 23 controls the operating speed, torque, and operating direction of each hydraulic actuator.

  Next, the drive control action of this hybrid type hydraulic excavator including the above charge / discharge action will be described.

  When the engine 20 is operated, the generator 21 is driven to generate power, the electric motor 24 is driven by the generated AC power, the hydraulic pump 25 is rotated, and each hydraulic actuator is operated as described above. Each excavator operation (excavation, traveling, turning) is performed.

  Here, basically, the electric motor 24 is driven by the electric power supplied from the generator 21 via the inverter 23, but at the time of heavy load, the electric power shortage is caused by the stored electric power of the battery 22 by the action of the switching means described above. In addition, the surplus power of the generator 21 is stored in the battery 22 when the load is light.

  On the other hand, when the load is light and the battery capacity is sufficient, the output of the engine 20 can be reduced, or the engine can be stopped and the electric motor 24 can be driven only by battery power.

  By such an action, engine load can be smoothed, noise and exhaust gas can be reduced, and fuel consumption can be reduced.

  According to this excavator, as described above, the rotational force is transmitted through the path of the engine 20-generator 21-electric motor 24-hydraulic pump 25, and the power unit is divided into the engine 20 + generator 21 group and the motor 24 + hydraulic pump 25 group. It becomes possible to install separately. Therefore, since a large installation space is not required in one place, it is particularly suitable for a small swivel excavator. Further, since the generator 21 and the motor 24 can be connected by electrical wiring, energy transmission loss can be greatly reduced.

  In FIG. 12, a single electric motor 24 and a hydraulic pump 25 are combined to form each hydraulic actuator (turning and traveling hydraulic motors 26, 27, and 28 and boom, arm, and bucket cylinders 31, 30, and 29). The required pressure oil is supplied to the hydraulic actuator, but each hydraulic actuator is driven independently by providing a dedicated electric motor and a hydraulic pump corresponding to each hydraulic actuator, that is, one actuator It is also possible for the pressure oil supplied for this to be unaffected by pressure oil for driving other hydraulic actuators.

  However, this Patent Document 1 does not disclose a technical idea that electric energy is regenerated during deceleration in each hydraulic actuator. Further, in this series system, the hydraulic pump 25 is not driven directly by the engine 20 but is driven by the electric motor 24, and the electric motor 24 is not a system for regenerating electric power. Further, since two generators 21 and a motor 24 are employed to form a hybrid type work machine, the storage capacity of the battery 22 is required to be relatively large, and the existing work machine From the above, it can be seen that it is not easy to easily add and add the generator 21 and the motor 24 in view of the system configuration of FIG.

On the other hand, although it is not the parallel system mentioned above, patent document 2 can be mentioned as an example of a hybrid type work machine. In paragraphs 0012 to 0014 of Patent Document 2,
“(1) To achieve the above object, the present invention provides a plurality of hydraulic actuators for driving a hydraulic working machine, a hydraulic pump for supplying pressure oil to the plurality of hydraulic actuators, and a direct or indirect connection to the hydraulic pump. In an energy regeneration device for a hydraulic working machine provided in a hydraulic working machine including a motor that is driven in a mechanical manner, the energy regenerating apparatus is directly connected to at least one of the plurality of hydraulic actuators or indirectly connected through a mechanical mechanism, Electric motor / generator for auxiliary driving / driven of hydraulic actuator, power storage means for transferring electric energy to / from the electric motor / generator, and electric motor / generator control means for controlling operation of the electric motor / generator With.

  In the present invention, based on the control of the electric / generator control means, the electric / generator provided in the at least one hydraulic actuator performs auxiliary driving / driven operation of the actuator, and exchanges electric energy with the power storage means. I do. As a result, for example, when the upper swing body is decelerated, the inertial kinetic energy generates electric power with the electric motor / generator attached to the turning hydraulic motor, or when the boom falls, the electric energy attached to the boom hydraulic cylinder is used with the potential energy. -It is possible to efficiently store (regenerate) the electric energy in the power storage means by generating power with a generator. Further, when the upper swing body is driven or the boom hydraulic cylinder is driven, the electric energy stored in the power storage means can be supplied to the motor / generator to drive the swing hydraulic motor and the boom hydraulic cylinder in an auxiliary manner. .

In the present invention, energy recovery can be performed with high efficiency as described above. Moreover, based on the existing hydraulic work machine, it can be realized with a simple configuration by adding an electric / generator to the hydraulic actuator and adding electric / generator control means and power storage means later. Is very easy. Further, when an engine is used as a prime mover, there is an effect that the fuel consumption per work can be improved and the engine exhaust gas amount can be reduced. "
It is described.

Further, referring to FIGS. 2 and 3 of Patent Document 2, the paragraphs 0026 to 0029 include
“In the present embodiment having the above-described configuration, for example, the operator operates the turning lever (not shown) of the operation lever device 15 to turn the upper turning body 2 of the excavator to the right in order to perform excavation and loading work. Is operated in the right turn direction (or left turn direction, the same correspondence in parentheses), a drive signal corresponding to the operation amount is generated from the controller 16 that has input the operation signal, and is output to the control valve device 14. The turning control valve is switched in response to the drive signal, and the pressure oil from the hydraulic pump 13 is supplied from the turning control valve to the turning hydraulic motor 10 and is driven to rotate rightward (or leftward). At this time, as shown in Fig. 3, when the operation amount x (the right direction is represented by positive) becomes equal to or greater than a predetermined value xo (or a predetermined value -xo The electric energy stored in the power storage device 19 is supplied to the motor / generator 17 under the control of the motor / generator control device 18 based on the signal from the controller 16, and the motor / generator 17 acts as the motor. As shown in FIG. 3, a torque To in the right turning direction (or a torque −To in the left turning direction) is generated, thereby assisting in driving the turning hydraulic motor 19.

  After that, for example, when the upper swing body 2 turns to some extent (for example, when the bucket 5 approaches the loading platform of the earth and sand transport dump truck), the operator performs the turning operation of the operation lever device 15 to stop the right (or left) turning operation. Return the lever (not shown) to the neutral position. In response, the drive signal from the controller 16 to the turning control valve becomes zero, the turning control valve returns to the neutral position, and the pressure oil supply from the hydraulic pump 13 to the turning hydraulic motor 10 is shut off. .

  At this time, since the upper swing body 2 driven to swing by the swing hydraulic motor 17 is a large object and its own weight is relatively heavy, the upper swing body 2 that is swiveling has a large inertia kinetic energy, Even if the pressure oil supply to the turning hydraulic motor 10 is interrupted, the turning movement is continued. In this embodiment using this, when the manipulated variable x falls within a predetermined range (−xi ≦ x ≦ xi) near 0 (neutral position), the motor / generator control device 18 based on the signal from the controller 16 Electric power is generated by the motor / generator 17 provided in the swing hydraulic motor 10 under the control. That is, in this case, the motor / generator 17 acts as a generator to generate power while generating torque -To (or torque To in the right turn direction) in the counterclockwise left turn direction to generate the inertial energy. This is converted into energy, and this electrical energy is efficiently stored (regenerated) in the power storage device 19. The electric energy stored in the power storage device 19 is supplied again to the motor / generator 17 when the upper revolving unit 2 is driven to turn, and is used to drive the turning hydraulic motor 10 as an auxiliary.

As described above, according to the present embodiment, energy recovery can be performed with high efficiency when the upper swing body 2 is decelerated and stopped. At this time, according to the configuration of the present embodiment, the electric / generator 17 is added to the turning hydraulic motor 10 among the hydraulic actuators 7, 8, 9, 10, 1l, 11R based on the existing hydraulic working machine. Can be realized with a simple configuration in which the motor / generator control device 18 and the power storage device 19 are added later, so that the practical application is very easy. Furthermore, the fuel consumption per operation of the engine 12 can be improved and the engine exhaust gas amount can be reduced. "
And regenerating the kinetic energy of the inertial body as electric energy when the inertial body driven by the hydraulic actuator is decelerated.

However, in the above-mentioned Patent Document 2, as described in the above paragraph 0026 and FIG.
“When the manipulated variable x (representing the right direction as positive) is greater than or equal to a predetermined value xo (or smaller than a predetermined value −xo), the power storage device 19 is controlled by the motor / generator control device 18 based on a signal from the controller 16. Is supplied to the motor / generator 17, and the motor / generator 17 acts as a motor to generate a torque To in the right turn direction (or a torque -To in the left turn direction) as shown in FIG. This assists the driving of the turning hydraulic motor 19. "

On the other hand, in paragraph 0028,
“When the manipulated variable x is within a predetermined range (−xi ≦ x ≦ xi) in the vicinity of 0 (neutral position), the motor / generator control device 18 is controlled based on a signal from the controller 16 to be attached to the turning hydraulic motor 10. The electric motor / generator 17 generates electric power, that is, in this case, the electric motor / generator 17 acts as a generator to generate a torque -To in the counterclockwise left-turn direction (or torque To in the right-turn direction). It generates electricity while it is generated, converts the inertial energy into electrical energy, and efficiently stores (regenerates) this electrical energy in the power storage device 19. "
As described above, in the control of the motor / generator 17 based on the controller 16, the torque T when acting as the motor and the generator is determined in accordance with the lever operation amount x (x0, xi). The torque T during driving and regeneration is both set to a predetermined value T0.

  A similar relationship is also shown in the regeneration control for the boom shown in FIG. 6 of Patent Document 2 as the motor torque Ti with respect to the lever operation amount y during driving and during regeneration.

  However, in the regenerative control of Patent Document 2, the main point is to use the motor / generator 17 as an auxiliary drive and driven means of the hydraulic actuator, and further, through the INV / CON 18 of the controller 16. In order to make the control relatively simple, the torque T0 is not determined based on the relationship between the pressure or flow rate of the supply pressure oil or the discharge pressure oil to the hydraulic actuator 10, and the amount of lever operation is simply determined. Correspondingly, control is performed to switch to a predetermined value T0. Therefore, when the hydraulic actuator is started or stopped, the motor / generator 17 is driven and regenerative control is switched. In addition, for example, when the set value T0 is larger during regeneration from a light load or low speed state, the swing motor is Chi on there is a fear that the mechanical shock caused to the drive system to be stopped. If T0 is changed in accordance with each state in order to avoid such a problem, there is a problem that the control of the controller becomes complicated after all.

  Further, in these Patent Documents 1 and 2, in contrast to the fact that the above-described electric drive device is placed in a severe temperature environment, the temperature rise of each part of the electric control device is generally reduced by a fan or the like. It is thought that it can be coped with by cooling, and no special countermeasure against the temperature rise has been proposed.

JP 2001-11888 A JP 2004-124381 A

  As a result of earnest research in view of the above circumstances, the present inventor detects the temperature of each part of the electric drive device constituting the hybrid work machine, and outputs the electric / generator and the hydraulic actuator based on the detected temperature. By changing the torque ratio, it is possible to suppress the temperature rise of each part of the electric drive unit, and to correlate with the differential pressure of the pressure oil at the pressure oil supply port and the discharge port of the hydraulic actuator corresponding to the motor / generator Thus, it has been found that the above-mentioned various problems can be basically solved by generating a control command to the inverter / converter connected to the motor / generator.

  Accordingly, an object of the present invention is to provide each electric circuit on the electric drive device side in a hybrid work machine having two types of drive systems: drive using a hydraulic pump driven by a prime mover as a drive source and drive using an electric motor. It is an object of the present invention to provide an operation control method and apparatus for a hybrid work machine in which temperature management is performed so that the temperature does not become inoperable due to a temperature rise of the portions.

  In order to achieve the above object, an operation control method for a hybrid work machine according to the present invention drives a hydraulic pump with a prime mover and supplies hydraulic oil discharged from the hydraulic pump to a hydraulic actuator via a switching valve. And an electric drive unit that includes a motor / generator, a power storage device, an inverter, and a control device that gives a control signal to the motor / generator, the power storage device, and the inverter. In the operation control method for a hybrid work machine configured to drive the common inertia body by adding the output torques of the drive device unit and the electric drive device unit, the control device controls the temperature of the electric drive device unit. Output torque of the hydraulic drive unit for detecting and driving the inertial body according to a change in the detected temperature and the electric drive unit Adjusting the ratio of the output torque, characterized in that.

  In that case, the ratio of the output torque of the electric drive unit to the output torque of the hydraulic drive unit can be reduced in accordance with the temperature rise of the electric drive unit.

  Further, in this case, while detecting the temperature of the electric drive unit, the ratio of the output torque between the hydraulic drive unit and the electric drive unit is reduced or changed when the temperature exceeds a predetermined temperature. Can be configured.

  Furthermore, the temperature of each of the electric drive unit and the hydraulic drive unit can be detected, and the heat balance of the electric drive unit can be maintained below the heat balance of the hydraulic drive unit.

  In order to achieve the above object, a hybrid work machine according to the present invention includes a hydraulic drive unit that drives a hydraulic pump with a prime mover and supplies discharge oil of the hydraulic pump to a hydraulic actuator via a switching valve; The motor / generator, power storage device, inverter connected to the hydraulic actuator, and an electric drive unit including a control device that gives a control signal to the motor / generator, power storage device, inverter, and the hydraulic drive device are provided. A hybrid work machine configured to drive a common inertial body by adding the output torques of the motor unit and the electric drive unit, and provided in at least one of the motor / generator, the power storage device, and the inverter The output torque is output to each of the temperature detection means, the hydraulic drive unit for driving the inertial body, and the electric drive unit. And a control device that adjusts a ratio of an output torque of the hydraulic drive unit and an output torque of the electric drive unit according to a change in temperature detected by the temperature detection unit. To do.

  In that case, a differential pressure detecting means for detecting the pressure of both ports of the hydraulic actuator provided with the motor / generator and generating a differential pressure thereof, and the electric motor in relation to the differential pressure detected by the differential pressure detecting means. The control device having torque command means for commanding the output torque of the generator can be provided.

  Further, in this case, when the torque command means relates the output torque of the motor / generator to the differential pressure of both ports of the hydraulic actuator, the torque control gain for the differential pressure when operating as a generator is set. It can be set larger than the gain of torque control for the differential pressure when operating as an electric motor.

  Further, in that case, the hydraulic actuator is constituted by a hydraulic motor, and the torque command means includes a rotary inertia body driven by the hydraulic motor, a driving / braking torque of the hydraulic motor and an electric motor / generator. The drive control is configured by the sum of the drive / brake torque, and the ratio of the output torque of the hydraulic motor in the sum of the output torques of the hydraulic motor and the electric / generator at the time of driving is set to the ratio of the output torque of the hydraulic motor at the time of braking. An adjusting means for adjusting the ratio to be larger than the ratio of the hydraulic motor braking torque can be provided.

  In this case, a bypass valve for short-circuiting both ports of the hydraulic motor by an external signal is provided as an element of the adjusting means in the process of driving the hydraulic motor by the rotary inertia body as the rotary inertia body is decelerated. be able to.

  Further, in this case, as the adjusting means, the hydraulic motor is provided with a relief valve for limiting the maximum driving pressure when the hydraulic motor is driven and stopped, and the operating pressure during acceleration of the relief valve is reduced and stopped. It can be configured to be higher than the working pressure at the time.

  In this case, the rotary inertia body may be a swivel base of the work machine, and the hydraulic motor may be a swivel hydraulic motor that rotationally drives the swivel base.

  According to the operation control method for a hybrid type work machine according to the present invention, a hydraulic drive unit that drives a hydraulic pump with a prime mover and supplies discharge oil of the hydraulic pump to the hydraulic actuator via a switching valve, and the hydraulic actuator The motor / generator, power storage device, and inverter provided together with the motor / generator, power storage device, and an electric drive device unit including a control device that gives a control signal to the inverter are provided. In the operation control method of a hybrid type work machine configured to add each output torque of the device unit and drive a common inertial body, the control device detects the temperature of the electric drive device unit and detects the detected temperature The ratio of the output torque of the hydraulic drive unit and the output torque of the electric drive unit for driving the inertial body according to the change of Since it is configured to adjust, the hydraulic drive device and the electric drive device are used together in order to enable the operation of the work machine even in an emergency situation due to a temperature rise in a poor environment, and the temperature of the electric drive device exceeds a predetermined value By reducing the driving force of the electric drive unit to suppress heat generation and improving the reliability of the electric drive unit, and increasing the output of the hydraulic drive unit to reduce the output of the electric drive unit The required output as a work machine can be maintained.

  According to the hybrid work machine of the present invention, a hydraulic drive unit that drives the hydraulic pump with a prime mover and supplies the hydraulic pump discharge oil to the hydraulic actuator via a switching valve, and the hydraulic actuator are provided together. The motor / generator, the power storage device, the inverter, and the motor / generator, the power storage device, and an electric drive device unit including a control device that gives a control signal to the inverter are provided. A hybrid type work machine configured to drive each of the output torques to drive a common inertial body, and a temperature detection means provided in at least one of the motor / generator, power storage device, and inverter; Instruct the hydraulic drive unit for driving the inertial body and the electric drive unit to calculate the respective output torques. Since the controller is configured to adjust the ratio of the output torque of the hydraulic drive unit and the output torque of the electric drive unit according to the change in the temperature detected by the temperature detection means, It is only necessary to install a temperature sensor in each part on the electric drive device side, and while the work machine is driven, the control device reduces or changes the ratio of the two output torques in relation to the detected temperature. The temperature rise of the circuit or the like can be avoided, so that the operator of the work machine can perform the operation work without worrying about the temperature rise of the electric circuit or the like.

  Hereinafter, an example based on an embodiment of the invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of a hydraulic excavator as a work machine. In FIG. 1, an excavator 10 has an upper swing body 13 mounted on a lower traveling body 11 driven by a hydraulic motor via a swing mechanism 12 so as to be rotatable. The upper swing body 13 is provided with a cab 14 on one front side thereof, and a boom 15 is attached to the front center portion so as to be able to be raised and lowered. An arm 16 is attached to the tip of the boom 15 so as to be rotatable up and down, and a bucket 17 is attached to the tip of the arm 16.

  FIG. 2 is a conceptual block diagram illustrating the basic configuration of the present invention. In FIG. 2, an inertial body 60 is turnably mounted on a lower traveling body 11 of a hydraulic excavator. As a drive device for turning the turning inertia body 60, an electric drive device portion ED including an electric motor / generator 70 and a hydraulic drive device portion HD including a hydraulic motor 58 that is a hydraulic actuator are provided as indicated by broken lines. Gears (not shown) attached to the output rotary shaft 70a of the motor / generator 70 and the output rotary shaft 58a of the hydraulic motor 58 are assembled so as to rotate via the splitter C. The rotary shaft 60a is coupled. Pressure oil from a pump 54 driven by a prime mover (not shown) is supplied to and discharged from the hydraulic motor 58 via a switching control valve 56. Reference numeral 58 b is setting means for setting an output torque (Tem) to be generated on the drive shaft 58 a of the hydraulic motor 58. As will be described later, the setting means 58b can be constituted by a relief valve.

  On the other hand, the electric drive unit ED includes an electric motor / generator 70, a motor unit 70A composed of an encoder 72 that detects the rotational phase angle of the electric motor / generator 70, and an inverter that performs power conversion between the motor unit 70A. / Converter unit 102 and power storage device 90 that stores electrical energy. The electric storage device 90 supplies required power via the inverter / converter unit 102 when the motor / generator 70 functions as an electric motor, and when the motor / generator 70 functions as a generator, that is, When braking the inertial body 60, the electric power generated via the inverter / converter unit 102 is received. The controller CU corresponds to the torque command means 104 in FIG. 3 and supplies torque command signals Tem and Teg to the hydraulic drive unit HD and the electric drive unit ED, respectively.

  Reference numerals S1, S2, and S3 are temperature sensors provided to detect the internal temperatures of the power storage device 90, the inverter / converter unit 102, and the motor unit 70A, respectively. Reference numeral S4 is a temperature sensor provided in the tank T.

  Reference numerals θ1, θ2, θ3, and θ4 indicate the detected temperature values of the temperature sensors S1, S2, S3, and S4.

  FIG. 3 is a detailed diagram illustrating the overall configuration of the present invention. In FIG. 3, reference numeral 50 is a hydraulic device of a hybrid work machine, and the hydraulic device 50 includes a prime mover 52 and a hydraulic pump 54. In FIG. 3, a hydraulic actuator 58 connected corresponding to one switching control valve 56 in the hydraulic device 50, an inertia body 60 driven by the hydraulic actuator 58, and a pilot operation pressure signal to the switching control valve 56. A pilot operated valve 59 that generates Pa and Pb is illustrated. Examples of the hydraulic actuator 58 include a turning hydraulic motor and a boom cylinder, and examples of the inertia body 60 include a turntable and a boom.

  Reference numeral 70 is an electric motor / generator composed of an AC motor attached to the hydraulic actuator 58. When the inertial body 60 is driven, a predetermined driving force is applied to the inertial body 60 in cooperation with the hydraulic actuator 58. In addition, when the inertial body 60 is decelerated and braked, a predetermined braking force is applied to the inertial body 60 in cooperation with the hydraulic actuator 58.

  Here, the reference symbol C indicates the combined state. Specifically, when the hydraulic actuator 58 is a hydraulic motor and the inertial body 60 is a rotary inertial body, the shaft of the motor / generator 70 is the hydraulic pressure. When the hydraulic actuator 58 is a hydraulic cylinder and the inertial body 60 is an inertial body that moves linearly, the shaft of the motor / generator 70 is coupled to the hydraulic shaft of the motor / generator 70. They are coupled via a linear motion rotation conversion mechanism comprising a pinion gear engaged with a rack provided in parallel with the rod of the cylinder.

  Reference numeral 72 is an encoder that detects the amount of rotation of the motor / generator 70. Reference numeral 80 is a differential pressure detecting means for detecting the pressure PA on the pressure oil supply port side and the pressure PB on the discharge port side of the hydraulic actuator 58 and generating the differential pressure D (= PA−PB). Further, reference numeral 90 denotes a power storage device including a battery and a capacitor, and the power storage device 102 is configured to supply electric power required when the motor / generator 70 acts as an electric motor via a power conversion unit 102 constituting the control device 100. 90. Further, the electric power generated when the motor / generator 70 acts as a generator is supplied to the power storage device 90 via the power conversion unit 102.

  Reference numeral 100 is control means for the entire hybrid work machine. Here, only the control portion directly related to the present invention in the control means 100 is illustrated as a block. The power converter 102 is a PWM (pulse width modulation) that generates and generates a known inverter / converter circuit 102a and a switching pulse train signal for turning on and off the gates of a plurality of large power transistors forming the inverter / converter circuit 102a. Instrument) 102b. Further, the power conversion unit 102 is coupled to the motor / generator 70 and outputs an output signal P of an encoder 72 that outputs the rotational angle position of the motor / generator 70, and although not shown, the motor / generator 70. The output signals from the detection part of the current flowing through each of the excitation phase windings are respectively input. The inverter circuit converts a DC voltage (current) into an AC voltage (current), and the converter circuit converts the AC voltage (current) into a DC voltage (current).

  Reference numeral 104 denotes torque command means, to which an output signal D of the differential pressure detection means 80 and detected temperatures θ1, θ2, θ3, θ4 of the temperature detection means are inputted. The function of the torque command means 102 is that the rising and falling timings of each pulse in the PWM 102b, that is, the switching phase and the width of each pulse for each large power transistor are changed to the signal P and the current flowing through each excitation phase winding. Calculation is generated based on this. The operation of the adjusting means 104a and the pilot operation signals Pa and Pb in the control means 100 will be described later.

  FIG. 4 shows a hydraulic apparatus in the case where the hydraulic actuator 58 in the hydraulic apparatus 50 of the working machine illustrated in FIG. 3 is a turning hydraulic motor, and the inertia body 60 is a rotary base that is a rotary inertia body. In FIG. 4, reference numeral 200 denotes a variable displacement pump, and the discharge flow rate to the discharge side line 200b is controlled by the swash plate adjusting mechanism 200a. Reference numeral 202 is a switching control valve that performs supply and discharge of pressure oil to and from the hydraulic motor 204 for turning via lines A and B. Reference numeral 202a is a switching control valve for supplying and discharging pressure oil to and from other hydraulic actuators (not shown).

  Above the switching control valve 202, a pressure control valve PCV that functions in a load sensing manner is provided. Reference numeral LSL is a line for load sensing. Reference numerals Pa and Pb indicate operation pressure signals from a pilot operation valve (not shown), and are respectively given to a pressure receiving portion of the switching control valve 202. Reference signs PA and PB indicate pressures at the pressure oil supply port and discharge port of the hydraulic motor 204. Reference numerals L and R indicate left rotation and right rotation of the hydraulic motor 204, respectively.

  Reference numeral 206 denotes a generator / motor that is provided alongside the hydraulic motor 204. The rotating shaft of the generator / motor 206 and the rotating shaft of the hydraulic motor 204 are mechanically coupled, coupled to the reduction gear mechanism 208, and further coupled to the swivel base 210 that is a rotary inertia body. Reference numeral 204a relates to the hydraulic motor 204 and is provided between the lines A and B on the opposite side of the switching control valve 202, and is opened when a predetermined condition is satisfied, that is, when the swivel base 210 is decelerated and braked. The reference symbol Sd indicates an open command signal. Reference numeral 204b is a known hydraulic braking circuit in which a pair of relief valves and a check valve are arranged to face each other. In FIG. 4, the set pressure of each relief valve is shown as constant, but the set pressure is variable. It is also possible to provide a relief valve of this type, and a set pressure signal in that case can be generated by the control means 100.

  Reference numerals 90 and 100 are the power storage device and the control means described with reference to FIG. 3, respectively, and indicate that they are electrically connected to the generator / motor 206 as indicated by a two-dot chain line.

  Reference numeral 212 denotes a motor for power generation. When the power storage level of a known power storage device 90 including a battery and a capacitor is lower than a predetermined value, the motor 212 is driven by the pump 216 to generate the generated energy. Is supplied to the power storage device 90. Here, the pressure oil to the pump 216 is supplied from the discharge line 200b via the on-off valve 214, and the on-off valve 214 is preferably supplied by a signal Si formed by the control means 100. Opened. In this case, as a condition for forming the signal Si, for example, when all the switching control valves 202, 202a of the hydraulic device 50 are in a neutral position and the power storage level of the power storage device 90 is a predetermined value or less. can do. The signal Si is defined as an external signal in the present invention.

  FIG. 5 shows a specific example of the on-off valves 204a and 214. FIG. 5A shows that when the on-off valve 204a is in the OFF position, the lines A and B are in the cut-off state, and the signal Sd Is given an ON position, and lines A and B communicate. The right side of FIG. 5A schematically shows that the control unit 100 determines whether or not the vehicle is decelerating / braking, and generates a signal Sd that commands the ON state when the result is affirmative Y.

  Further, in FIG. 5B, when the on-off valve 214 is in the OFF position, the lines LA and LB are in the cut-off state, and when the signal Si is given, the line LA and LB are in communication. On the right side of FIG. 5B, the control unit 100 detects the battery storage level, determines whether the actual level (Bact) is equal to or lower than the target level (Btgt), and the determination result is positive. Further, it is schematically shown that a signal Si for instructing the ON state is generated when it is Y and it is determined whether or not all the hydraulic actuators are in a non-operating state and the result is NO.

  FIG. 6 is a graph showing the time transition of the generator / motor 206 and the hydraulic motor 204 from the acceleration drive state of the swivel base 210 to the deceleration drive state of the deceleration drive. Represents the total torque Tt on the vertical axis, and FIG. 5B shows the pressure on each port of the hydraulic motor 204 in MPa on the vertical axis.

  In FIG. 5A, in the acceleration driving state, the torque generated by the hydraulic motor 204 is indicated as Tm, and the torque generated by the generator / motor 206 as an electric motor is indicated as Te (motor). In the case of this acceleration drive, the total torque Tt supplied to the swivel base 210 is the sum of Tm and Te (motor), as shown. On the other hand, in the braking state by deceleration driving, the torque absorbed by the hydraulic motor 204 is shown as Tm, and the torque absorbed by the generator / motor 206 as a generator is shown as Te (generator). In the case of this deceleration drive, the total torque Tt absorbed from the swivel base 210 by the hydraulic motor 204 and the generator / motor 206 is the sum of Tm and Te (generator), as shown. The reference sign dTe is the difference between the torque Te (generator) during deceleration driving and the torque Te (motor) during acceleration driving as shown in the figure.

  In the case of a large rotating inertial load such as the swivel base 210, the torque required for acceleration driving is large, so that driving by the hydraulic motor 204 is mainly preferable. Therefore, at the time of acceleration driving, as shown in the figure, the ratio of the torque Te (motor) to the torque Tm is made small. On the other hand, during deceleration driving, as shown in the figure, the ratio of torque Te (generator) to torque Tm is adjusted to be large. By doing in this way, it is possible to take in the kinetic energy at the time of deceleration drive to the electrical storage apparatus 90 efficiently.

  Reference sign ET1 indicates that electrical energy is supplied from the power storage device 90 side to the power generation / motor 206 during acceleration driving, and reference sign ET2 refers to the power storage device from the power generation / motor 206 side during deceleration driving. 90 indicates that electrical energy is supplied. Reference symbols xa and xd indicate the transition of torque Tm during acceleration driving and deceleration driving of the hydraulic motor 204, and reference symbols ya and yb indicate torque Te (motor) during acceleration driving and deceleration driving of the generator / motor 206. ) And Te (generator).

  In FIG. 6B, PA indicated by the solid line indicates the port pressure on the line A side of the hydraulic motor 204 during acceleration driving and deceleration driving, respectively, and the broken line PB indicates during acceleration driving and deceleration driving, respectively. The port pressure on the line B side of the hydraulic motor 204 is shown. As can be seen from the figure, since the magnitudes of PA and PB are reversed during acceleration driving and deceleration driving, the signal Sd is generated with this reversal (state change) as a state change from acceleration to deceleration. It can be used to In the present invention, the magnitudes of the torques xa and ya during acceleration driving in FIG. (The ratios of the torque xd and yd during deceleration driving or the magnitudes thereof are also the same.) Various methods are conceivable to achieve this, but preferably the ratio of xa and ya and the ratio of xd and yd are set respectively. In that case, the ratio may be determined using the differential pressure D (= PA−PB) between PA and PB in FIG. In particular, during deceleration driving, the differential pressure between the pressures PA and PB detected by opening the on-off valve 204a by the signal Sd is very small, and the ratio of Te (generator) to Tm corresponding to this state. 3, the swirl kinetic energy of the swivel base 210 can be almost entirely taken out as electric energy on the power generator / motor 206 side and stored in the power storage device 90, except for the loss in the channel CR of FIG. . The on-off valve 204a is an example when the adjusting means 104a in FIG. 3 is implemented as a hydraulic circuit.

FIG. 7 illustrates the relationship between the pressures PA and PB detected at the ports on the lines A and B in the turning hydraulic motor 204 and the operation lever of the pilot operation valve. Is for explaining pressures PA and PB detected at the ports on the line A side and B side corresponding to the left rotation L and right rotation R of the hydraulic motor 204,
In the block BLK, when the hydraulic motor 204 rotates clockwise, the line A side of the hydraulic motor is a pressure oil supply port (Ain) and the line B side is a discharge port (Bout). In that case, when each detected pressure is PA> PB, the generator / motor 206 operates as a motor, and when PA <PB, the generator / motor 206 operates as a generator. Similarly, when the hydraulic motor 204 is in the left rotation L, the line B side of the hydraulic motor is the pressure oil supply port (Bin) and the line A side is the discharge port (Aout). In that case, when each detected pressure is PA <PB, the generator / motor 206 operates as a generator, and when PA> PB, the generator / motor 206 operates as a motor.

  FIG. 4B shows the waveforms of the detected pressures PA and PB in the case of full operation and half operation of the operation lever of the pilot operation valve in acceleration driving and deceleration driving as graphs in the upper and lower stages, respectively.

  FIG. 8 is a flowchart for explaining a control function of the control means 100 of FIG. In FIG. 8, step ST0 indicates that the operator of the work machine 10 is in the operating state. In step ST1, the presence / absence of the pilot operation pressure signal Pa or Pb of the pilot operation valve 59 is determined. (Note that the signals Pa and Pb are given to the torque command means 104 in FIG. 3.) If the determination in step ST1 is negative, that is, N, the duration of N in step ST2 is, for example, 3 seconds or more. In step ST4, the mechanical brake is operated, and in step ST5, the command torque Te to the generator / motor 206 (FIG. 4) is set to zero. If it is less than 3 seconds in step ST2, the process returns to step ST1 and the determination is repeated.

  When the result is YES in step ST1, the direction of rotation of the generator / motor 206 is determined in step ST3. In the case of the right rotation R, in step 6, the pressures PA and PB of the respective ports of the hydraulic motor 204 are determined. In the case of positive Y, in step ST7, the command torque Te to the generator / motor 206 is determined as Tem. The generator / motor 206 is defined to operate as a motor to contribute to acceleration driving. Further, when the result is negative in step ST6, in step ST8, the command torque Te to the generator / motor 206 is defined as Teg, that is, the generator / motor 206 is defined to operate as a generator to contribute to the deceleration drive.

  Next, in step ST9, the value of Tem is set as a function f of a value obtained by applying a coefficient c1 to the difference between PA and PB. In step ST10, the value of Teg is set as a function f of a value obtained by applying a coefficient c2 to the difference between PA and PB. Subsequent to step ST9, in step ST11, the magnitude of PA and a preset value PAc for preventing cavitation is compared and determined. As a result, in the case of positive Y, the process proceeds to step ST10 in order to avoid cavitation. The Tem set in ST9 is corrected to the torque Teg corresponding to the aforementioned deceleration driving. Further, when the result in Step ST11 is negative N, the Tem set in Step ST9 is executed as a torque command value, and the process returns to Step ST1. Similarly, Teg set in step ST10 is executed as a torque command value, and the process returns to step ST1.

  In Step ST3, when N is negative, that is, when the left rotation is L, although not shown, the same steps as Steps ST6 to ST11 are performed, and thus the description thereof is omitted.

  FIG. 9 is a hybrid operation control for explaining how the controller CU changes the torque command value applied to the hydraulic drive unit HD and the electric drive unit ED in accordance with the detected temperature from each temperature sensor of FIG. It is a flowchart of the program prepared for.

  In FIG. 9, when the program is started, the elapse of the sampling time Ts is checked in step ST1. If the determination in step ST1 is affirmative (hereinafter referred to as Y), the detected temperature data of the temperature sensors in each part in the ED is checked in step ST3, and the comparison between the detected temperature and the corresponding set temperature is performed in step ST4. To do.

  Next, in step ST5, it is checked whether or not all detected temperatures are equal to or lower than the respective set values. If Y in step ST5, it is checked in step ST6 whether the ratio Q is related to the detected temperature. This check can also be set in advance by the operator in the parameter area of the controller CU.

  If it is Y in step ST6, mode 2 is executed and the process returns to step ST1. If the determination in step ST6 is negative (hereinafter referred to as N), mode 3 is executed in step ST9, and the process returns to step ST1. In the case of N in step ST5, mode 1 is executed in step ST8, and the process returns to step ST1.

  Modes 1, 2, and 3 are defined as shown. That is, as shown in FIG. 10A, in mode 1, the ratio Q of the torque command value Tem (Teg) to the motor / generator to the torque command value Tm to the hydraulic motor is reduced by a predetermined amount P%.

  As shown in FIG. 10B, in mode 2, the ratio Q of the torque command value Tem (Teg) to the motor / generator with respect to the torque command value Tm to the hydraulic motor is set corresponding to the detected temperature θi. Correction is made in proportion to the difference with the temperature θis. This means that, for example, when driving in winter or cold regions, when the detected temperature θi is considerably lower than the set temperature θis, the torque command value for the motor / generator is relative to the torque command value for the hydraulic motor. Is to increase.

  For mode 3, for example, the processing process of FIG. 8 corresponds. In this case, all the detected temperatures are in a state below the respective set values.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to those shown in FIGS. 1 to 10, and various modifications can be made by those skilled in the art. For example, as shown in FIG. 11, as a hydraulic actuator for driving an inertial body, a boom generator, a traveling hydraulic motor, etc. can be provided with a generator / motor.

  Further, the flowcharts shown in FIGS. 9 and 10 are only one example, and there may be only one temperature sensor. Further, the set temperature of one sensor is not limited to one. For example, a dangerous temperature can be set in addition to a temperature at which an electric circuit such as an inverter normally operates.

  Further, the reduction amount P% in mode 1 does not necessarily have to be a constant. Following the relationship between the number of times the sampling time Ts has passed and the change in the detected temperature, and when the temperature change is slow, the reduction amount P It is also possible to adopt a modification in which% is set to a larger value, or when the temperature change is rapid, the reduction amount P% is set to a smaller value.

  Furthermore, it is possible to delete the steps ST6 and ST7 and execute the mode 3 of the step ST9 in the flowchart of FIG.

It is a figure which shows schematic structure of the working machine to which this invention is applied. It is a conceptual block diagram explaining the basic composition of the present invention. It is detail drawing explaining the whole structure of this invention. FIG. 4 is a view showing the hydraulic apparatus in the hydraulic apparatus of FIG. 3 when a hydraulic actuator for turning is used as a hydraulic actuator, and a turntable that is a rotary inertia body is used as an inertia body. FIG. 5 shows a specific example of each on-off valve in FIG. 4, (a) is when the on-off valve is in the OFF position, the lines A and B are in the shut-off state, and when the signal Sd is given, the ON position is reached , Lines A and B communicate with each other, and (b) shows that when the on-off valve is in the OFF position, the lines LA and LB are in the cut-off state, and when the signal Si is applied, the line LA and LB are in the ON position. LB indicates communication. It is a graph which shows the time transition characteristic of the generator / motor and the hydraulic motor in the state from the acceleration to the deceleration of the swivel, wherein (a) shows the overall torque Tt on the vertical axis and (b) shows the hydraulic pressure on the vertical axis. Indicates the pressure at each port of the motor. The relationship between the pressures PA and PB detected at the ports on the line A side and the B side in the turning hydraulic motor and the operation lever of the pilot operation valve will be described, and (a) shows the left side of the hydraulic motor. FIG. 4B is a block diagram illustrating the pressures PA and PB detected at the ports on the line A side and B side corresponding to the rotation and the right rotation. FIG. The waveforms of the detected pressures PA and PB when the full operation is performed and when the half operation is performed are shown as graphs in the upper and lower stages, respectively. It is a flowchart explaining the function of the torque instruction means in FIG. Prepared for hybrid operation control to explain how the controller CU changes the torque command value applied to the hydraulic drive unit and the electric drive unit according to the detected temperature from each temperature sensor in FIG. It is a flowchart of a program. FIG. 9 shows an example of each mode, where (a) is an example of mode 1 and (b) is an example of mode 2. It is detail drawing of the boom part as an inertial body to which this invention is applied. It is a figure which shows the block structure of the drive system and control system of the hydraulic shovel by the conventional hybrid system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Excavator 11 Lower traveling body 12 Turning mechanism 13 Upper turning body 14 Cab 15 Boom 16 Arm 17 Bucket 50 Hydraulic device 52 Motor 54 Hydraulic pump 56 Switching control valve 58 Hydraulic actuator 59 Pilot operation valve 60 Inertial body 70 Electric motor / generator 72 Encoder 80 Differential pressure detection means 90 Power storage device 100 Control means 102 Power conversion unit 104 Torque command means 200 Variable displacement pump 202 Switching control valve 204 Hydraulic motor 204a On-off valve 204b Relief valve unit 206 Electric motor / generator 208 Reduction gear mechanism 210 Rotational inertia Body 212 Generator 214 On-off valve 216 Hydraulic pump

Claims (11)

A hydraulic drive unit that drives a hydraulic pump with a prime mover and supplies the hydraulic pump discharge oil to a hydraulic actuator via a switching valve, an electric / generator, a power storage device, an inverter, An electric drive unit comprising a control device for supplying a control signal to the motor / generator, power storage device, and inverter is provided, and the output torque of the hydraulic drive unit and the electric drive unit is added to form a common inertial body. In the operation control method for a hybrid work machine configured to drive, the control device includes:
Detecting the temperature of the electric drive unit;
Adjusting the ratio of the output torque of the hydraulic drive unit and the output torque of the electric drive unit for driving the inertial body according to the change in the detected temperature;
An operation control method for a hybrid type work machine.   2. The operation control method for a hybrid type work machine according to claim 1, wherein the ratio of the output torque of the electric drive unit to the output torque of the hydraulic drive unit is reduced in accordance with a temperature rise of the electric drive unit. .   Claims configured to reduce or change the ratio of the output torque between the hydraulic drive unit and the electric drive unit when the temperature exceeds a predetermined temperature while detecting the temperature of the electric drive unit. Item 3. An operation control method for a hybrid work machine according to Item 1 or 2.   The temperature of each of the electric drive unit and the hydraulic drive unit is detected, and the heat balance of the electric drive unit is maintained below the heat balance of the hydraulic drive unit. The operation control method of the hybrid type work machine described in 2. A hydraulic drive unit that drives a hydraulic pump with a prime mover and supplies the hydraulic pump discharge oil to a hydraulic actuator via a switching valve, an electric / generator, a power storage device, an inverter, An electric drive unit comprising a control device for supplying a control signal to the motor / generator, power storage device, and inverter is provided, and the output torque of the hydraulic drive unit and the electric drive unit is added to form a common inertial body. A hybrid work machine configured to drive,
Temperature detection means provided in at least one of the motor / generator, power storage device, and inverter;
The hydraulic drive unit for driving the inertial body and the electric drive unit are instructed to calculate respective output torques, and the output torque of the hydraulic drive unit according to a change in temperature detected by the temperature detection means The control device for adjusting the ratio of the output torque of the electric drive unit;
A hybrid work machine characterized by comprising: Differential pressure detecting means for detecting the pressure of both ports of the hydraulic actuator provided with the motor / generator and generating the differential pressure;
The control device having torque command means for commanding output torque of the motor / generator in relation to the differential pressure detected by the differential pressure detection means;
The hybrid work machine according to claim 5, further comprising:   In the torque command means, when associating the output torque of the motor / generator with the differential pressure of both ports of the hydraulic actuator, the gain of torque control for the differential pressure when operating as a generator is operated as an electric motor. The hybrid type work machine according to claim 6, wherein the gain is set to be larger than a gain of torque control with respect to the differential pressure in the case.   The hydraulic actuator is constituted by a hydraulic motor, and the torque command means includes a rotary inertia body driven by the hydraulic motor, a driving / braking torque of the hydraulic motor and a driving / braking torque of the electric / generator. The ratio of the output torque of the hydraulic motor in the sum of the output torques of the hydraulic motor and the motor / generator at the time of driving is calculated as the ratio of the braking torque of the hydraulic motor in the sum of the braking torques during braking. The hybrid work machine according to any one of claims 5 to 7, further comprising an adjusting means for adjusting the ratio to be larger than the ratio.   A bypass valve that short-circuits both ports of the hydraulic motor by an external signal is provided as an element of the adjusting means in the process of driving the hydraulic motor by the rotary inertia body along with the deceleration of the rotary inertia body. The hybrid type work machine according to claim 8.   As the adjusting means, the hydraulic motor is provided with a relief valve for limiting the maximum driving pressure at the time of driving and stopping of the hydraulic motor, and the operating pressure at the time of acceleration acceleration of the relief valve is determined from the operating pressure at the time of deceleration stop. The hybrid work machine according to claim 8 or 9, wherein the hybrid work machine is configured to be high.   11. The hybrid work machine according to claim 8, wherein the rotary inertia body is a swivel base of the work machine, and the hydraulic motor is a swivel hydraulic motor that rotationally drives the swivel base.

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