JP2006336432A - Work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with a power generation means in a hydraulic pressure actuator control circuit, by directly driving a hybrid type driving device by energy possessed by a return fluid discharged from a hydraulic pressure actuator. <P>SOLUTION: This work machine has the hydraulic pressure actuator control circuit 25 for controlling a working fluid supplied to a traveling motor and a work actuator from pumps 17A and 17B of the hybrid type driving device 10, and a revolution control circuit 28 for operating as an electric motor and operating as a generator when braking revolution of an upper revolving body. In the hydraulic pressure actuator control circuit 25, an energy regenerative motor 26 is arranged in a return passage 56 for passing the return fluid recovered from the work actuator. The energy regenerative motor 26 is operated by the return fluid, and drives a motor-driven generator 22 of the hybrid type driving device 10 via a regenerative clutch 111. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a work machine including a hybrid drive device.

BACKGROUND ART A drive device for a work machine such as a hydraulic excavator has a hybrid drive device that includes a generator driven by an engine and a capacitor that stores electric power generated by the generator. On the other hand, a fluid pressure actuator control circuit such as a boom cylinder, a stick cylinder, and a bucket cylinder includes an electric motor or a motor / generator that operates with electric power supplied from at least one of a generator and a capacitor of a hybrid drive device, and these electric motors or A pump or a pump motor operated by an electric motor / generator is provided. For example, the control circuit for the boom cylinder is supplied from a bidirectional discharge type pump / motor that has both a pump function for supplying a working fluid and a fluid pressure motor function that operates by receiving the supply of the working fluid, and a generator or a capacitor. And an electric motor / generator having both an electric motor function that is driven by the generated electric power to drive the pump / motor and an electric generator function that is driven by the pump / motor to generate electric power (for example, see Patent Document 1).
JP 2004-190845 A (page 7, FIG. 1)

  The boom cylinder control circuit is a combination of a pump / motor and an electric motor / generator, and the electric power generated by the boom cylinder control circuit is stored in the storage battery of the hybrid drive unit. In addition, since the surplus energy of the working fluid in the fluid pressure actuator control circuit is converted into electric power and stored in the storage battery of the hybrid drive device, it is necessary to install power generation means in the fluid pressure actuator control circuit. is there.

  The present invention has been made in view of the above points, and by allowing the hybrid drive device to be directly driven by the energy of the return fluid discharged from the fluid pressure actuator, An object of the present invention is to provide a work machine that does not require power generation means.

  According to the first aspect of the present invention, an upper revolving body that can be swung by a turning electric motor / generator is provided for a lower traveling body that can travel by a travel motor, and the upper revolving body is operated by a work actuator. A work machine provided with a device, an engine, an electric motor / generator driven by the engine and functioning as a generator and receiving electric power to function as an electric motor, and an electric motor / generator functioning as the generator A hybrid drive device comprising a battery for storing electric power supplied from a generator and supplying electric power to an electric motor / generator functioning as an electric motor; and a pump driven by at least one of the engine and the electric motor / generator; Fluid for controlling the working fluid supplied from the pump of the hybrid drive device to the traveling motor and the working actuator Electricity supplied from the actuator control circuit and the electric storage device of the hybrid drive unit acted as a motor / generator for turning as a motor and generated from a motor / generator for turning operated as a generator during turning braking of the upper-part turning body A swivel control circuit that collects electric power in the accumulator, and the fluid pressure actuator control circuit is provided in a return fluid passage through which the return fluid recovered from the working actuator passes and is operated by the return fluid to A work machine including an energy regenerative motor that drives an electric motor / generator, and a regenerative clutch that is interposed between the energy regenerative motor and the electric motor / generator of the hybrid drive device to intermittently transmit rotation.

  According to a second aspect of the present invention, the return fluid passage in the work machine according to the first aspect includes one return passage having an energy regeneration motor, the other return passage branched on the upstream side of the energy regeneration motor, A flow rate control valve for controlling a flow rate ratio between the flow rate in the return passage and the flow rate in the other return passage is provided.

  According to a third aspect of the present invention, the working device in the working machine according to the first or second aspect sequentially connects the boom, the stick, and the bucket, and the working actuator rotates the boom and the stick. The energy recovery motor is provided in the return fluid passage from the boom cylinder.

  According to a fourth aspect of the present invention, there is provided a working fluid supply passage for a boom cylinder in which a plurality of pumps of the hybrid drive device in the work machine according to the third aspect are installed, and the working fluid is supplied from one pump to the boom cylinder; The working fluid supply passage for the stick cylinder that supplies the working fluid from the pump to the stick cylinder, and the position and flow that allow the working fluid to flow from the working fluid supply passage for the boom cylinder to the working fluid supply passage for the stick cylinder are cut off. A solenoid valve between the boom and the stick that is displaced between the position where the working fluid is supplied and a position where the working fluid is allowed to flow from the working fluid supply passage for the stick cylinder to the head side of the boom cylinder and a position where the flow is blocked. And a solenoid valve between the stick and boom that is displaced between the two.

  According to the first aspect of the present invention, the hybrid drive device is provided via the regenerative clutch by the energy regenerative motor provided in the return fluid passage through which the return fluid recovered from the working actuator of the fluid pressure actuator control circuit passes. Because the motor / generator is directly driven, the generator in the fluid pressure actuator control circuit can be made unnecessary without converting the surplus energy of the working fluid in the fluid pressure actuator control circuit into electric power. Efficiency can be improved. Furthermore, when stopping the upper turning body turned by the turning electric motor / generator that operates as an electric motor for the lower traveling body, by operating the turning electric motor / generator as a generator by the turning control circuit, The hybrid drive system can brake the turning of the upper revolving structure and efficiently recover the electric power generated from the electric motor / generator for turning together with the electric power generated from the generator driven by the energy regenerative motor in the accumulator of the hybrid drive device. It can be regenerated as the pump power of the device.

  According to the second aspect of the invention, the return fluid discharged from the boom cylinder to the return fluid passage is divided into one return passage and the other return passage, and the divided flow rate ratio is controlled by the flow rate control valve. Since the energy regenerative motor is operated by one return fluid whose flow rate is controlled by this flow rate control valve, the flow ratio diverted to the energy regenerative motor side gradually increases from the time when the return fluid from the boom cylinder is generated. Thus, the occurrence of shock can be prevented, and the boom cylinder can be stably operated by suppressing the rapid load fluctuation of the boom cylinder.

  According to a third aspect of the present invention, the fluid pressure actuator control circuit connects the regenerative clutch when operating the working actuator with the working fluid supplied from the main pump of the hybrid drive device, thereby From the energy regenerative motor operated by the return fluid discharged from the cylinder, the power generated by efficiently inputting power to the motor / generator of the hybrid drive device can be stored in the capacitor, and the hybrid drive device When using an electric motor / generator as an electric motor, the regenerative clutch can be disconnected to prevent the energy regenerative motor from becoming a load on the electric motor / generator, and the boom that functions as an electric motor by the electric power from the capacitor of the hybrid drive device The motor / generator can be operated efficiently.

  According to the fourth aspect of the present invention, the working fluid supplied from one pump to the boom cylinder is supplied from another pump by opening the boom-stick electromagnetic valve and closing the stick-boom electromagnetic valve. By combining the working fluid supplied to the stick cylinder to increase the speed of the stick cylinder, the solenoid valve between the boom and stick is closed and the solenoid valve between the stick and boom is opened. The working fluid supplied to 1 can be merged with the working fluid supplied from one pump to the head side of the boom cylinder, so that the boom-up operation can be speeded up.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS. 1 and 2 and another embodiment shown in FIG. Note that oil and hydraulic pressure are used as the fluid and the fluid pressure.

  As shown in FIG. 2, the work machine 1 is a hydraulic excavator, and an upper swing body 4 is rotatably provided on a lower traveling body 2 via a swing bearing portion 3. A power unit 5 such as a fluid pressure pump, a cab 6 that protects an operator, and the like are mounted to form an airframe 7. The lower traveling body 2 includes traveling motors 2trL and 2trR for driving the left and right crawler belts, and the upper revolving body 4 is a turning electric motor for driving a turning speed reduction mechanism provided in the turning bearing portion 3. A generator (not shown in FIG. 2) is provided.

  A work device 8 is attached to the upper swing body 4. In this work device 8, a boom 8bm, a stick 8st, and a bucket 8bk are pin-coupled to a bracket (not shown) of the upper swing body 4 so as to be turnable in turn, and the boom 8bm is turned by a boom cylinder 8bmc as a work actuator. Then, the stick 8st is rotated by a stick cylinder 8stc as a working actuator, and the bucket 8bk is rotated by a bucket cylinder 8bkc as a working actuator.

  In the hybrid drive device 10 shown in FIG. 1, a clutch 12 that connects and disconnects rotational power output from the engine 11 is connected to an engine 11, and an input shaft 13 of a power transmission device 14 is connected to the clutch 12. The two variable displacement pumps 17A and 17B are connected to the output shaft 15 of the power transmission device 14.

  These pumps 17A and 17B are driven by the engine 11 to function as a generator on the input / output shaft 21 of the power transmission device 14 in a parallel relationship with the engine 11, and also function as a motor upon receiving power supply. A motor / generator 22 is connected. The motor power of the motor / generator 22 is set smaller than the engine power. The motor / generator 22 is connected to a motor / generator controller 22c such as an inverter.

  The motor / generator controller 22c stores electric power supplied from the motor / generator 22 that functions as a generator and stores electric power to the motor / generator 22 that functions as a motor via a capacitor controller 23c such as a converter. A capacitor 23 to be supplied is connected. The battery 23 is a battery, a capacitor, or the like.

  The power transmission device 14 in the hybrid drive device 10 incorporates a continuously variable transmission mechanism such as a toroidal type or a planetary gear type, and can output the continuously variable rotation to the output shaft 15 by an external control signal. Yes.

  The pumps 17A and 17B in the hybrid drive device 10 supply a hydraulic fluid such as hydraulic fluid stored in the tank 24 to the fluid pressure actuator control circuit 25. An energy regenerative motor 26 is provided in the fluid pressure actuator control circuit 25, and the energy regenerative motor 26 is electrically connected to the hybrid drive device 10 via a regenerative clutch 111 and a rotation shaft 112 that intermittently transmit rotation. A generator 22 is connected.

  With respect to the fluid pressure actuator control circuit 25, the turning electric motor / generator 4sw is operated as an electric motor by the electric power supplied from the capacitor 23 of the hybrid drive device 10, and the upper rotating body 4 is operated as a generator at the time of turning braking. A turning control circuit 28 for collecting the electric power generated from the turning electric motor / generator 4sw in the battery 23 is installed.

  This turning control circuit 28 includes a turning electric motor / generator 4sw for turning the upper turning body 4 via a turning speed reduction mechanism 4gr, and a turning electric / generator controller 4swc such as an inverter. The electric power supplied from the electric storage device 23 of the driving device 10 functions as an electric motor, and when it is forcibly rotated by an inertial turning force, it functions as an electric generator and collects electric power in the electric storage device 23.

  The speed of the engine 11, the engagement / disengagement of the clutch 12, the speed change of the power transmission device 14, and the like are controlled by signals output from a controller (not shown).

  In the fluid pressure actuator control circuit 25 shown in FIG. 1, the pump passages 31 and 32 connected to the discharge ports of the pumps 17 </ b> A and 17 </ b> B operate as electromagnetic proportional valves provided in the bypass passage returned to the tank 24. It is connected to electromagnetic valves 33 and 34, and is connected to an electromagnetic valve 35 that operates as a travel straight valve.

  The solenoid valves 33 and 34 function as bypass valves. When there is no operation signal for the operator to operate the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, and 8bkc, the pump passages 31 and 32 are tanked by the control signal from the controller. 24 is controlled to the fully open position, and the operator is displaced to the closed position in proportion to the magnitude of the operation signal for operating the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, and 8bkc.

  The solenoid valve 35 can supply the working fluid from the two pumps 17A, 17B to the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, 8bkc at the left working position shown in FIG. In other words, the working fluid equally divided to the two traveling motors 2trL and 2trR is supplied from only one of the pumps 17B, and straight traveling is enabled.

  The fluid pressure actuator control circuit 25 includes a travel control circuit 36 that controls the working fluid supplied from the pumps 17A and 17B of the hybrid drive device 10 to the travel motors 2trL and 2trR, and the pumps 17A and 17B of the hybrid drive device 10. The working device control circuit 37 for controlling the working fluid supplied to the working actuators 8bmc, 8stc, and 8bkc for operating the working device 8 is provided.

  The traveling control circuit 36 includes electromagnetic valves 43 and 44 for controlling the direction and flow rate of the working fluid supplied through the working motor working fluid supply passages 41 and 42 drawn from the electromagnetic valve 35 that operates as a straight traveling valve. I have.

  The working device control circuit 37 includes a boom control circuit 45 that controls the working fluid supplied to the boom cylinder 8bmc from the pumps 17A and 17B of the hybrid drive device 10, and a stick from the pumps 17A and 17B of the hybrid drive device 10. A stick control circuit 46 for controlling the working fluid supplied to the cylinder 8stc, and a bucket control circuit 47 for controlling the working fluid supplied from the pumps 17A and 17B of the hybrid drive device 10 to the bucket cylinder 8bkc. Yes.

  The boom control circuit 45 includes an electromagnetic valve 49 that controls the direction and the flow rate of the working fluid supplied through the boom cylinder working fluid supply passage 48 drawn from the solenoid valve 35 that operates as a straight traveling valve. The working fluid supply / discharge passages 51 and 52 of the valve 49 are communicated with the head side chamber and the rod side chamber of the boom cylinder 8bmc.

  In the head side working fluid supply / discharge passage 51, an electromagnetic valve 53 functioning as a fall prevention valve is interposed, and when the boom is stopped, the solenoid valve 53 is controlled to be switched to the check valve position on the left side to lower the boom 8bm by its own weight. To prevent. Further, an electromagnetic valve 54 functioning as a regeneration valve is provided between both the working fluid supply / discharge passages 51 and 52, and this solenoid valve 54 is controlled to be switched to the check valve position when the boom is lowered, so that the head of the boom cylinder 8bmc A part of the return fluid discharged from the side chamber is regenerated into the rod side chamber.

  On the tank passage side of the solenoid valve 49, a return fluid passage 55 for diverting the return fluid discharged from the boom cylinder 8bmc is provided, and in one return passage 56 and the other return passage 57 of the return fluid passage 55, Flow ratio control valves 58 and 59 for controlling the flow ratio of the flow divided into the return passages 56 and 57 are provided. The flow ratio control valves 58 and 59 are branched on one upstream side of the one electromagnetic valve 58 and one electromagnetic valve 58 for flow control provided in one return passage 56 having the energy regeneration motor 26. The other return valve 57 is provided with the other electromagnetic valve 59 for flow rate control.

  Then, the rotational speed of the energy regeneration motor 26 to be operated is controlled by the amount of return fluid in one return passage 56 whose flow rate is controlled by the flow rate control valves 58 and 59.

  The energy regeneration motor 26 is preferably operated when the electromagnetic valve 49 for direction control and flow rate control is in the right ventricle in FIG. That is, when the boom is lowered, the head side working fluid supply / discharge passage 51 of the boom cylinder 8bmc communicates with the return fluid passage 55, and the energy regenerative motor 26 is spared by the boom's own weight due to the return fluid discharged from the head side of the boom cylinder 8bmc. It is desirable to operate with

  The stick control circuit 46 includes an electromagnetic valve 62 that controls the direction and the flow rate of the working fluid supplied through the stick cylinder working fluid supply passage 61 drawn from the solenoid valve 35 that operates as a straight traveling valve. The working fluid supply / discharge passages 63 and 64 of the valve 62 communicate with the head side chamber and the rod side chamber of the stick cylinder 8stc. In addition, an electromagnetic valve 65 that functions as a regeneration valve from the rod side to the head side is provided between both working fluid supply / discharge passages 63 and 64, and this solenoid valve 65 is switched to the check valve position when the stick-in is lowered. By controlling, the return fluid discharged from the rod side chamber of the stick cylinder 8stc is regenerated into the head side chamber.

  The bucket control circuit 47 includes an electromagnetic valve 67 that controls the direction and the flow rate of the working fluid supplied through the bucket cylinder working fluid supply passage 66 drawn from the solenoid valve 35 that operates as a straight traveling valve. The working fluid supply / discharge passages 68 and 69 of the valve 67 are communicated with the head side chamber and the rod side chamber of the bucket cylinder 8bkc.

  Between the stick cylinder working fluid supply passage 61 and the head side of the boom cylinder 8bmc, there is provided a circuit-to-circuit communication passage 71 between the stick and boom that communicates these, and a circuit-to-circuit communication passage 71 between the stick and boom. The stick-to-boom solenoid valve 72 is displaced between a position allowing the one-way flow from the stick cylinder working fluid supply passage 61 to the head side of the boom cylinder 8bmc and a position blocking the flow. Is provided.

  Between the boom cylinder working fluid supply passage 48 and the stick cylinder working fluid supply passage 61, there is provided an inter-circuit communication passage 73 between the boom and the stick that communicates between them. In the inter-communication passage 73, there is provided a boom-stick solenoid valve 74 having a position for allowing a one-way flow from the boom cylinder working fluid supply passage 48 to the stick cylinder 8stc and a position for blocking. .

  The solenoid valves 53, 54, 65, 72, and 74 are switching valves having a flow rate adjusting function with a built-in check valve.

  Solenoid valves 33, 34, 35, 43, 44, 49, 53, 54, 58, 59, 62, 65, 67, 72, and 74 are a solenoid proportionally controlled by a controller (not shown) and a return spring (not shown). ), And the displacement is controlled to a position where the solenoid exciting force and the spring restoring force are balanced.

  Next, the function and effect of the illustrated embodiment will be described.

  The boom control circuit 45 diverts the return fluid discharged from the boom cylinder 8bmc in the return fluid passage 55, and controls the diverted flow rate ratio by the flow rate control valves 58 and 59. The flow rate control valve 58 , 59, the energy regenerative motor 26 is actuated by one return fluid whose flow rate is controlled, and the motor / generator 22 of the hybrid drive apparatus 10 is directly driven by the energy regenerative motor 26 via the regenerative clutch 111. Therefore, it is possible to prevent the occurrence of shock by gradually increasing the flow ratio of the flow diverted to the energy regeneration motor 26 from the time when the return fluid from the boom cylinder 8bmc is generated, and to suppress the sudden load fluctuation of the boom cylinder 8bmc. Thus, stable operation of the boom cylinder 8bmc can be obtained.

  That is, when the boom 8bm of the working device 8 falls by its own weight, the return fluid discharged from the head side of the boom cylinder 8bmc is gradually increased in flow rate ratio to the energy regeneration motor 26 side, so that the energy of the return fluid is increased. Can be absorbed smoothly by the energy regeneration motor 26, and a sudden load fluctuation on the head side of the boom cylinder 8bmc can be suppressed, so that the weight falling operation of the boom 8bm can be stabilized.

  The flow ratio control valves 58, 59 can be installed with one solenoid valve 58 and the other solenoid valve 59 separately at any place in one return passage 56 and the other return passage 57, respectively. It is possible to freely control the flow rate ratio and flow rate of the return fluid flowing to the energy regeneration motor 26 side by individually controlling the opening degrees of the passage 56 and the other return passage 57 without being related to each other.

  Further, by connecting the regenerative clutch 111, the energy regenerative motor 26 operated by the return fluid discharged from the boom cylinder 8bmc of the fluid pressure actuator control circuit 25 is connected to the hybrid drive device 10 via the regenerative clutch 111. Since the motor / generator 22 is directly driven, it is possible to eliminate the need for the generator in the fluid pressure actuator control circuit 25 without converting surplus energy of the working fluid into electric power in the fluid pressure actuator control circuit 25. And energy efficiency can be improved.

  On the other hand, when the electric motor / generator 22 of the hybrid drive device 10 is used as an electric motor, the regenerative clutch 111 can be disconnected to prevent the energy regenerative motor 26 from becoming a load on the electric motor / generator 22, The boom motor / generator 22 that functions as an electric motor can be efficiently operated by the electric power.

  Further, when the upper swinging body 2 swung by the turning electric motor / generator 4sw that operates as an electric motor is stopped with respect to the lower traveling body 4, the turning electric motor / generator 4sw is generated by the turning control circuit 28. As a result, it is possible to brake the turning of the upper-part turning body 4, and the power generated from the turning electric motor / generator 4 sw is combined with the electric power generated from the electric motor / generator 22 driven by the energy regeneration motor 26. It can be efficiently collected in the battery 23 of the drive device 10 and can be regenerated as pump power of the hybrid drive device 10.

  By opening the boom-stick solenoid valve 74 and closing the stick-boom solenoid valve 72, the working fluid supplied from one pump 17A to the boom cylinder 8bmc is supplied from the other pump 17B to the stick cylinder 8stc. It is possible to increase the speed of the stick cylinder 8stc by merging with the working fluid to be used, and by closing the boom-stick solenoid valve 74 and opening the stick-boom solenoid valve 72, the stick cylinder from the other pump 17B The working fluid supplied to 8stc is joined to the working fluid supplied to the head side of the boom cylinder 8bmc from the pump 17A through the boom cylinder working fluid supply passage 48 and the left chamber of the direction control solenoid valve 49. Thus, the boom-up operation can be speeded up.

  Furthermore, when the boom-stick electromagnetic valve 74 is controlled to the shut-off position and the boom control circuit 45 and the stick control circuit 46 are separated and independent, the boom system and the stick system are separated from each other, Can be controlled separately.

  Next, FIG. 3 shows another embodiment of the hybrid drive apparatus 10, and a first clutch 12 a that connects and disconnects the rotational power output from the engine 11 is connected to the engine 11. An input shaft 13 of the power transmission device 14 is connected to the clutch 12a, and a plurality of variable displacement pumps 17A and 17B are connected to the output shaft 15 of the power transmission device 14 in series.

  The engine 11 is connected in series with a starter motor generator 18 that is driven by the engine 11 and functions as a generator and also functions as an electric motor that starts the engine 11 by receiving power. The starter motor generator 18 is connected to a starter motor generator controller 18c such as an inverter.

  A second clutch 12b is connected in parallel to the first clutch 12a to the input / output shaft 21 of the power transmission device 14, and the second clutch 12b is connected to the pumps 17A and 17B in parallel with the engine 11. An electric motor / generator 22 that is driven by the engine 11 and functions as a generator and receives electric power and functions as an electric motor is connected. The motor power of the motor / generator 22 is set smaller than the engine power. The motor / generator 22 is connected to a motor / generator controller 22c such as an inverter.

  The starter motor generator controller 18c and the motor / generator controller 22c receive the electric power supplied from the starter motor generator 18 and the motor / generator 22 that function as a generator via a capacitor controller 23c such as a converter. It is connected to a starter motor generator 18 that stores and functions as an electric motor, and a capacitor 23 that supplies electric power to the motor / generator 22. The battery 23 is a battery, a capacitor, or the like.

  The power transmission device 14 in the hybrid drive device 10 incorporates a continuously variable transmission mechanism such as a toroidal type or a planetary gear type, and can output continuously rotated rotations to the output shafts 15a and 15b by external control signals. It has become.

  The pumps 17A and 17B in the hybrid drive device 10 supply a hydraulic fluid such as hydraulic fluid stored in the tank 24 to the fluid pressure actuator control circuit 25. An energy regenerative motor 26 is provided in the fluid pressure actuator control circuit 25, and the electric power recovered from the motor / generator 22 driven by the energy regenerative motor 26 is stored in the capacitor 23.

  With respect to the fluid pressure actuator control circuit 25, the turning electric motor / generator 4sw is operated as an electric motor by the electric power supplied from the capacitor 23 of the hybrid drive device 10, and the upper rotating body 4 is operated as a generator at the time of turning braking. A turning control circuit 28 for collecting the electric power generated from the turning electric motor / generator 4sw in the battery 23 is installed.

  This turning control circuit 28 includes a turning electric motor / generator 4sw for turning the upper turning body 4 via a turning speed reduction mechanism 4gr, and a turning electric / generator controller 4swc such as an inverter. The electric power supplied from the electric storage device 23 of the driving device 10 functions as an electric motor, and when it is forcibly rotated by an inertial turning force, it functions as an electric generator and collects electric power in the electric storage device 23.

  The speed of the engine 11, the engagement / disengagement of the first clutch 12a, the speed change of the power transmission device 14, and the like are controlled by signals output from a controller (not shown).

  Next, the function and effect of the embodiment shown in FIG. 3 will be described.

  The engine 11 and the starter motor generator 18 are connected in series (series system), and the engine 11 and the motor / generator 22 are connected in parallel to the power transmission device 14 (parallel system). The system includes a first clutch 12a provided between the engine 11 and the power transmission device 14 and a second clutch provided between the motor / generator 22 and the power transmission device 14 according to the work situation. In the series system, the engine power is stored in the capacitor 23 via the starter motor generator 18, and in the parallel system, the engine power is stored in the capacitor 23 via the motor / generator 22. So, depending on the work situation, you can take advantage of both of them.

  For example, during heavy load work with a large pump load, both the clutches 12a and 12b are connected and the starter motor generator 18 and the motor / generator 22 function as an electric motor. Is input to the crankshaft of the engine 11 and motor power from the motor / generator 22 is input to the power transmission device 14 to drive the pumps 17A and 17B with these three powers.

  Also, in the series system, when there is a surplus in engine power relative to the power required from the pumps 17A and 17B, the starter motor generator 18 is caused to function as a generator, and the electric power generated from the starter motor generator 18 is reduced. When the engine power is stored in the battery 23 and the engine power cannot satisfy the power required from the pumps 17A and 17B, the starter motor generator 18 is caused to function as an electric motor, and the starter motor generator power is added to the engine 11. If the engine power still does not meet the power required by the pumps 17A and 17B, connect both clutches 12a and 12b to allow the motor / generator 22 of the parallel system to function as an electric motor and make the engine 11 starter motor. Add generator power and electric / generator power.

  When working with light loads with a relatively small pump load, connect one clutch 12a or 12b and disconnect the other clutch 12b or 12a, and connect the pumps 17A and 17B with one of the engine 11 or motor / generator 22 To drive.

  For example, the first clutch 12a provided between the engine 11 and the power transmission device 14 is disconnected, and the second clutch 12b is connected, so that the engine 11 is stopped in a quiet state. Since the pumps 17A and 17B can be driven by operating the motor / generator 22 as an electric motor with the stored power, work up to engine repair in the event of a failure in the engine 11 or engine noise becomes a problem Suitable for low noise work in urban areas or at night.

  Further, the first clutch 12a is disconnected, the second clutch 12b is connected, and when the pumps 17A and 17B are driven using the motor / generator 22 as an electric motor, the engine 11 is operated to start the starter motor power generation. When the machine 18 is driven as a generator, the battery 23 can be charged during work.

  On the other hand, when the first clutch 12a is connected and the second clutch 12b is disconnected, the engine 11 can efficiently drive only the pump load without dragging the motor / generator 22.

  Also, when both clutches 12a and 12b are connected, if there is no pump load or it is light, starter motor generator 18 and motor / generator 22 function as a generator, and engine power is used as a starter motor generator. 18 and the motor / generator 22, and the capacitor 23 can be efficiently charged by the starter motor generator 18 and the motor / generator 22.

  Thus, when both clutches 12a and 12b are connected, a large pump power can be obtained by simultaneously using the power of the engine 11 and the power of the motor / generator 22 via the power transmission device 14. The starter motor generator 18 connected in series to the engine 11 functions as an electric motor for starting the engine, and can function as a generator driven by the engine 11 when the engine load is small. Since the starter motor generator 18 can be generated independently of the hydraulic system by disengaging the first clutch 12a, the battery 23 together with the motor / generator 22 can be charged efficiently.

  The accumulator 23 stores the electric power supplied from the starter motor generator 18 and the motor / generator 22 that function as a generator, and is also driven by the energy regeneration motor 26 in the fluid pressure actuator control circuit 25. Since the electric power recovered from the engine is also stored, the pump can be driven for a long time by the motor / generator 22 when the engine is stopped when sufficient electric power is supplied.

1 is a circuit diagram showing an embodiment of a hybrid drive device for a work machine and a fluid pressure actuator control circuit according to the present invention. It is a side view of a working machine same as the above. It is a circuit diagram which shows other embodiment of a hybrid type drive device and fluid pressure actuator control circuit same as the above.

Explanation of symbols

1 Working machine 2 Lower traveling body
2trL, 2trR Travel motor 4 Upper swing body
4sw Electric motor / generator for turning 8 Working device
8bm boom
8st stick
8bk bucket
8bmc Boom cylinder as working actuator
8stc Stick cylinder as working actuator
8bkc Bucket cylinder as working actuator
10 Hybrid drive unit
11 engine
17A, 17B pump
22 Electric generator
23 Battery
25 Fluid pressure actuator control circuit
26 Energy regeneration motor
28 Control circuit for turning
48 Working fluid supply passage for boom cylinder
55 Return fluid passage
56, 57 Return passage
58, 59 Flow ratio control valve
61 Working fluid supply passage for stick cylinder
72 Solenoid valve between stick and boom
74 Solenoid valve between boom and stick
111 Regenerative clutch

Claims (4)

A work machine in which an upper turning body that can be turned by a turning electric motor / generator is provided for a lower traveling body that can be driven by a running motor, and a work device that is operated by a working actuator is provided on the upper turning body. There,
An engine, an electric motor / generator driven by the engine and functioning as a generator and receiving electric power to function as an electric motor, and an electric motor that stores electric power supplied from the electric motor / generator functioning as the electric generator A hybrid drive device comprising a battery for supplying electric power to the motor / generator functioning as a pump and a pump driven by at least one of the engine and the motor / generator;
A fluid pressure actuator control circuit for controlling the working fluid supplied from the pump of the hybrid drive device to the travel motor and the working actuator;
The electric motor / generator for turning is operated as an electric motor by the electric power supplied from the electric storage device of the hybrid drive device, and the electric power generated from the electric motor / generator for turning operated as the generator at the time of turning braking of the upper-part turning body is collected in the electric storage device. A control circuit for turning,
Fluid pressure actuator control circuit
An energy regenerative motor that is provided in a return fluid passage through which a return fluid recovered from the working actuator passes and is actuated by the return fluid to drive the electric / generator of the hybrid drive device;
A work machine comprising: a regenerative clutch that is interposed between an energy regenerative motor and an electric motor / generator of a hybrid drive device to intermittently transmit rotation. The return fluid passage is
One return path having an energy regenerative motor;
The other return path branched on the upstream side of the energy regeneration motor;
The work machine according to claim 1, further comprising: a flow rate control valve that controls a flow rate ratio between a flow rate in one return passage and a flow rate in the other return passage. The work equipment connects the boom, stick and bucket in sequence,
The working actuator includes a boom cylinder that rotates the boom, a stick cylinder that rotates the stick, and a bucket cylinder that rotates the bucket.
The work machine according to claim 1 or 2, wherein the energy regenerative motor is provided in a return fluid passage from the boom cylinder. A plurality of hybrid drive pumps are installed,
A working fluid supply passage for the boom cylinder that supplies the working fluid from one pump to the boom cylinder;
A working fluid supply passage for a stick cylinder that supplies working fluid from another pump to the stick cylinder;
An electromagnetic valve between the boom and the stick that is displaced between a position that enables the flow of the working fluid from the working fluid supply passage for the boom cylinder to the working fluid supply passage for the stick cylinder and a position that blocks the flow;
A stick-to-boom solenoid valve displaced between a position allowing the working fluid flow from the stick cylinder working fluid supply passage to the head side of the boom cylinder and a position blocking the flow. The work machine according to claim 3, wherein

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