JP2006336849A - Turning drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly supply fluid pressure energy generated in a turning system to the outside of the turning system. <P>SOLUTION: A turning control circuit 91 is separately mounted with respect to a fluid pressure actuator control circuit 25, wherein a turning pump motor 95 is connected to closed circuits 92, 93 of a turning motor 4swh through a solenoid valve 94 taken as a direction control valve. A turning power generator 96 is connected to the turning pump motor 95, and to a capacitor 23 of a hybrid type drive device 10. A communication passage 97 to the outside of a system which supplies working fluid to the lower travelling body and the liquid pressure actuator of the working device is led out of piping between the turning pump motor 95 and solenoid valve 94, and provided with a communication passage solenoid valve 98 in the communication passage 97 to the outside of a system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a turning drive device including a turning motor that receives a supply of a working fluid and drives a load to turn.

When a hybrid drive device is used in a work machine such as a hydraulic excavator, an electric motor is generally used as a turning actuator for turning the upper turning body with respect to the lower traveling body. The upper swing body is swiveled (see, for example, Patent Document 1).
JP 2004-190845 A (6th page, FIG. 1)

  Since the upper swinging body has a large inertial force, its electric motor functions as a generator during swing braking, so it is possible to store the swing energy in the battery as electric power, but an actuator other than the swing system receives the supply of working fluid. In the case of a fluid pressure actuator that operates, surplus energy generated in the swing system cannot be directly supplied from the swing system to a fluid pressure actuator other than the swing system.

  The present invention has been made in view of these points, and an object of the present invention is to provide a turning drive device that can directly supply fluid pressure energy generated in the turning system to the outside of the turning system.

  The invention described in claim 1 functions as a swing motor that swings and drives a load upon receiving a supply of working fluid, and a pump that is connected to the swing motor in a closed circuit and supplies the working fluid to the swing motor and is discharged from the swing motor. A turning pump motor that functions as a fluid pressure motor by the working fluid, a directional control valve that has a neutral position and a directional control position that closes the space between the turning pump motor and the turning motor, and fluid during turning braking of the load A rotating electric motor / generator that functions as a generator driven by a rotating pump / motor functioning as a pressure motor and that functions as an electric motor that receives electric power to drive the rotating pump / motor as a pump; The electric motor / generator for turning that functions as an electric motor while storing the electric power supplied from the electric motor / generator for turning functioning as a motor An accumulator for supplying electric power, an external communication passage for supplying a working fluid from the closed circuit between the turning pump / motor and the directional control valve to the outside of the turning system, and an outside connecting passage provided outside the turning system. An operation for replenishing the working fluid to a closed circuit between the communication passage solenoid valve displaced between the position where the working fluid can be supplied and the position where the flow is interrupted, and the swiveling pump motor and the direction control valve A swivel drive device comprising fluid replenishing means.

  According to a second aspect of the present invention, the working fluid replenishing means in the turning drive device according to the first aspect is a working fluid replenishing pump.

  According to the first aspect of the invention, when the load is driven to turn, the direction control valve is controlled to the direction control position and the communication passage electromagnetic valve is controlled to be shut off to make the turning system independent. When the turning motor / generator is operated as an electric motor by the electric power supplied from the battery and the turning pump / motor is driven as a pump, the turning motor is operated by the generated working fluid pressure, and the load is independent only by the turning system. When the load is stopped, the turning pump motor is operated as a fluid pressure motor by the working fluid discharged as a pump by the turning motor rotating by the inertia of the load, and the turning electric motor / generator Because it is driven as a generator, the inertial kinetic energy of the load can be converted into electrical energy, and the power can be efficiently recovered in the battery while braking the turning of the load. When a large amount of working fluid is not required in the swivel system, the connecting passage solenoid valve is controlled to a position that allows the working fluid to be supplied to the outside of the swivel system, and then the swivel electric・ The generator drives the swivel pump / motor as a pump. The swivel pump / motor is supplied with the working fluid by the working fluid replenishing means, and is connected to the working fluid via the communication passage solenoid valve and the external communication passage. The working fluid can be directly supplied to the outside of the swirling system that requires the pump, and the main pump can be reduced in size by driving the swiveling pump / motor as a pump.

  According to the second aspect of the present invention, the working fluid replenishment pump can forcibly replenish the working fluid to the suction side of the swiveling pump / motor, and the working fluid can be efficiently supplied to the outside of the revolving system by the swirling pump / motor. I can do it well.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS. 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 working 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 sequentially rotatable, the boom 8bm is rotated by a boom cylinder 8bmc, It is rotated by the stick cylinder 8stc, and the bucket 8bk is rotated by the bucket cylinder 8bkc.

  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. Two variable capacity main pumps 17A and 17B are connected to the output shaft 15 of the power transmission device.

  The main pumps 17A and 17B are driven by the engine 11 to function as a generator and function as a motor by being supplied with electric power to the input / output shaft 21 of the power transmission device 14 in a parallel relationship with the engine 11. 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 main pumps 17A and 17B in the hybrid drive device 10 supply a working fluid such as hydraulic oil 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 is recovered from a boom motor / generator 87 driven by the energy regenerative motor 26 via a generator controller 27c such as a converter thereof. Electric power is stored in the battery 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 main pumps 17A and 17B operate as electromagnetic proportional valves provided in the bypass passages returned to the tank 24. Are connected to electromagnetic valves 33 and 34, and are also connected to an electromagnetic valve 35 that operates as a straight traveling 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 main pumps 17A, 17B to the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, 8bkc at the left working position shown in FIG. When switched, the working fluid equally divided into the two traveling motors 2trL and 2trR is supplied from only one main pump 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 main pumps 17A and 17B of the hybrid drive device 10 to the travel motors 2trL and 2trR, and the main pump 17A of the hybrid drive device 10. , 17B, a working device control circuit 37 for controlling the working fluid supplied to the working actuators 8bmc, 8stc, 8bkc for operating the working device 8.

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

  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 working fluid supply / discharge passage 51 on the head side, an electromagnetic valve 53 functioning as a fall prevention valve is interposed. When the boom is stopped, the electromagnetic valve 53 is controlled to be switched to the check valve position on the left side and lowered by the weight of the boom 8bm. 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.

  In the boom cylinder working fluid supply passage 48 for supplying the working fluid from the main pumps 17A, 17B of the hybrid drive device 10 to the boom cylinder 8bmc, a boom assist pump 84as for assisting the flow rate of the working fluid is provided. It is connected via a supply passage 85.

  The energy regenerative motor 26 provided in one return passage 56 through which the return fluid discharged from the boom cylinder 8bmc passes is driven by the energy regenerative motor 26 to supply power to the battery 23 of the hybrid drive device 10. A boom motor / generator 87 is connected to the boom assist pump 84as via the clutch 88.The boom motor / generator 87 functions as a generator and functions as an electric motor by the electric power supplied from the capacitor 23. ing. The clutch 88 transmits power to the boom assist pump 84as from the boom motor / generator 87 that functions as an electric motor, and disconnects the boom motor / generator 87 that functions as a generator from the boom assist pump 84as.

  Then, the rotational speed of the energy regenerative motor 26 to be operated is controlled by the amount of return fluid in one of the return passages 56 whose flow rate is controlled by the flow rate control valves 58 and 59, and for the boom driven by this energy regenerative motor 26 Electric power is supplied to and stored in the battery 23 of the hybrid drive device 10 by the motor / generator 87.

  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 working fluid supply / discharge passage 51 on the head side of the boom cylinder 8bmc communicates with the return fluid passage 55, and the energy regeneration motor 26 is caused by the boom's own weight by the return fluid discharged from the head side of the boom cylinder 8bmc. It is desirable to operate with a margin.

  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 bucket and the stick which communicates between them. In the inter-communication passage 73, there is provided an electromagnetic valve 74 between the bucket and the stick that has a position that allows a one-way flow from the boom cylinder working fluid supply passage 48 to the stick cylinder 8stc and a position that blocks it. .

  In the boom cylinder working fluid supply passage 48, between the branch portion of the bucket cylinder working fluid supply passage 66 and the junction from the boom assist pump 84as, the working fluid to the bucket cylinder 8bkc is supplied to the boom cylinder 8bmc. An electromagnetic valve 89 between the bucket and the boom is provided which is displaced between a position where supply is possible as a one-way flow to the position and a position where flow is interrupted.

  A turning control circuit 91 is provided separately from the fluid pressure actuator control circuit 25. The turning control circuit 91 controls the working fluid supplied to the turning motor 4swh that drives the upper turning body 4 to turn through the turning speed reduction mechanism 4gr.

  This turning control circuit 91 is provided with a solenoid valve 94 as a directional control valve having a flow rate control function in the closed circuits 92 and 93 of the turning motor 4swh, and for turning to the closed circuits 92 and 93 via this solenoid valve 94. A pump / motor 95 is connected. The turning pump motor 95 functions as a pump that supplies the working fluid to the turning motor 4swh, and also functions as a fluid pressure motor by the working fluid discharged from the turning motor 4swh.

  The electromagnetic valve 94 has a throttle switching valve function that adjusts the opening degree between a neutral position that closes between the swing pump motor 95 and the swing motor 4swh and a fully open position for right rotation and left rotation.

  A turning electric motor / generator 96 is connected to the turning pump / motor 95. The turning electric motor / generator 96 is connected to a turning electric motor / generator controller 96c such as an inverter, and the turning electric motor / generator controller 96c is connected to the capacitor 23 of the hybrid drive device 10. .

  The turning electric motor / generator 96 functions as a generator that is driven by a turning pump motor 95 that functions as a fluid pressure motor during turning braking of the upper turning body 4 and supplies electric power to the capacitor 23 of the hybrid drive device 10. At the same time, it functions as an electric motor that drives the turning pump motor 95 as a pump by the electric power supplied from the capacitor 23.

  That is, the battery 23 stores the electric power supplied from the turning electric motor / generator 96 functioning as the generator, and supplies the electric power to the turning electric motor / generator 96 functioning as the electric motor.

  An external communication passage 97 for supplying a working fluid to the lower traveling body 2 and the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, and 8bkc of the lower traveling body 2 and the work device 8 from the piping between the swing pump / motor 95 and the solenoid valve 94 Has been withdrawn.

  In this extraneous communication passage 97, the flow is cut off from the one-way flow position that enables supply of working fluid to the lower traveling body 2 and the fluid pressure actuators 2trL, 2trR, 8bmc, 8stc, 8bkc of the work device 8. A communication passage solenoid valve 98 whose opening degree is adjusted between the positions is provided.

  A working fluid replenishment pump 99 as a working fluid replenishing means for replenishing the working fluid is connected to a pipe between the turning pump motor 95 and the electromagnetic valve 94.

  Between the boom assist working fluid supply passage 85 of the boom assist pump 84as and the discharge passage 31 of the one main pump 17A, an inter-pump communication passage 101 that connects these passages is provided. This inter-pump communication passage 101 Among them, there is provided an electromagnetic valve 102 between the pumps that has a position that allows a one-way flow from the boom assist working fluid supply passage 85 of the boom assist pump 84as to the discharge passage 31 of the main pump 17A and a position that blocks it. It has been.

  The solenoid valves 53, 54, 65, 72, 74, 89, 98, and 102 are switching valves having a flow rate adjusting function incorporating a check valve.

  Various solenoid valves 33, 34, 35, 43, 44, 49, 53, 54, 58, 59, 62, 65, 67, 72, 74, 89, 94, 98, 102 are proportionally controlled by a controller (not shown) A solenoid and a return spring (not shown) are provided, respectively, and 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.

  When the upper swing body 4 is driven to swing relative to the lower traveling body 2 of the work machine 1, the electromagnetic valve 94 is controlled to the right or left direction control position and the electric power from the battery 23 of the hybrid drive device 10 is controlled. The swivel pump / motor 95 is actuated by the working fluid pressure generated by the swivel pump / motor 95 driven by the swivel motor / generator 96, and the upper swing body 4 is swung independently only by the swivel system. At the time of braking which can be driven and the upper swing body 4 is stopped, the communication passage electromagnetic valve 98 is closed, and the swing motor 4swh rotating by the inertial motion of the upper swing body 4 is driven by the working fluid discharged as a pump. 95 is operated as a fluid pressure motor load, and the turning electric motor / generator 96 is driven as a generator. Therefore, the inertial kinetic energy of the upper swing body 4 is converted into electric energy, and the upper swing body 4 is turned. Electric power can be efficiently collected in the battery 23 of the hybrid drive device 10 while braking the movement.

  On the other hand, when the swing motor 4swh does not require a large amount of working fluid, the solenoid valve 94 is moved closer to the neutral position, and the connecting passage solenoid valve 98 is moved closer to the one-way flow position to operate as a motor. The swiveling pump / motor 95 is driven as a pump by 96, and the swiveling pump / motor 95 is supplied to the outside communication passage 97 via the communication passage solenoid valve 98 while being refilled with the working fluid by the working fluid replenishment pump 99. The working fluid can be directly supplied to the lower traveling body 2 that needs the working fluid and the fluid pressure actuator control circuit 25 of the work device 8 that discharges the working fluid.

  That is, the external communication passage 97 is connected to the discharge passage 32 of the main pump 17B that supplies the working fluid to the boom cylinder 8bmc, the stick cylinder 8stc, and the travel motors 2trL and 2trR. Sufficient working fluid can be supplied from the main pumps 17A and 17B and the turning pump motor 95 functioning as a pump. Further, the main pumps 17A and 17B can be reduced in size by driving the turning pump / motor 95 as a pump.

  The fluid pressure actuator control circuit 25 controls the working fluid supplied from the main pumps 17A and 17B of the hybrid drive device 10 to the travel motors 2trL and 2trR, the boom cylinder 8bmc, the stick cylinder 8stc, and the bucket cylinder 8bkc. By disconnecting 88, power is efficiently input from the energy regenerative motor 26 operated by the return fluid discharged from the boom cylinder 8bmc to the boom motor / generator 87 in the no-load state. It can be stored in the battery 23 of the hybrid drive device 10, and the energy of the return fluid discharged from the boom cylinder 8bmc can be effectively regenerated.

  In particular, when the boom 8bm of the work device 8 falls by its own weight, the energy of the return fluid discharged from the head side of the boom cylinder 8bmc is absorbed by the boom electric motor / generator 87 from the energy regenerative motor 26 and hybrid type. It can be stored in the battery 23 of the driving device 10.

  When the clutch 88 is connected, the boom assist pump 84as is driven by the boom motor / generator 87 that functions as an electric motor by the electric power from the battery 23 of the hybrid drive apparatus 10, and the boom assist pump 84as Since the working fluid can be supplied to the cylinder 8bmc, the working fluid can be supplied to the boom cylinder 8bmc from the boom assist pump 84as in addition to the main pumps 17A and 17B and the turning pump motor 95 functioning as a pump. A large amount of working fluid can be supplied from the pump, and the workability can be further improved by further increasing the speed of the boom-up operation.

  Further, the return fluid discharged from the boom cylinder 8bmc to the return fluid passage 55 is divided into one return passage 56 and the other return passage 57, and the divided flow ratio is controlled by the flow ratio control valves 58 and 59. The energy regenerative motor 26 is operated by one return fluid whose flow rate is controlled by the flow ratio control valves 58 and 59, and the boom motor / generator 87 is driven by the energy regenerative motor 26. Since the electric power is supplied to the storage battery 23, it is possible to prevent the occurrence of shock by gradually increasing the flow rate ratio diverted to the energy regenerative motor 26 from the time when the return fluid from the boom cylinder 8bmc is generated. By suppressing the sudden load fluctuation of 8bmc, 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.

  In addition, since the solenoid valve 89 between the bucket and the boom is provided in the working fluid supply passage 48 for the boom cylinder, the amount of working fluid supplied from the main pump 17A and the boom assist pump 84as can be reduced by opening the solenoid valve 89. Can be supplied to the boom cylinder 8bmc in combination with the working fluid supply amount from the engine, and the boom cylinder 8bmc can be used to increase the speed of boom-up operation, improving workability.By closing this solenoid valve 89, the bucket cylinder 8bkc High pressure can be secured.

  Further, since the stick-boom electromagnetic valve 72 is provided in the circuit-to-circuit communication path 71 between the stick and boom that communicates the working fluid supply passage 61 for the stick cylinder and the head side of the boom cylinder 8bmc, the electromagnetic valve 72 Is controlled to a one-way flow position, in addition to the working fluid supplied from the main pump 17A and the boom assist pump 84as to the head side of the boom cylinder 8bmc through the left chamber of the solenoid valve 49, the other main pumps The working fluid from 17B can also be supplied to the head side of the boom cylinder 8bmc via this electromagnetic valve 72, and the boom-up operation by the boom cylinder 8bmc can be speeded up, so that workability can be improved. On the other hand, by closing the solenoid valve 72, it is possible to secure a working fluid supply amount from the other main pump 17B to the stick cylinder 8stc.

  In addition, since the electromagnetic valve 74 between the bucket and the stick is provided in the circuit-to-circuit communication path 73 between the bucket and the stick, the electromagnetic valve 74 is opened to the one-way flow position and the electromagnetic valves 72 and 89 are closed. The working fluid supplied from one main pump 17A to the boom cylinder 8bmc is merged with the working fluid supplied from the other main pump 17B to the stick cylinder 8stc, so that the speed of the stick cylinder 8stc can be increased and the bucket stick By closing the electromagnetic valve 74 and opening the electromagnetic valves 72 and 89, the working fluid supplied from the other main pump 17B to the stick cylinder 8stc is supplied from the main pump 17A to the boom cylinder working fluid supply passage 48, By joining the working fluid supplied to the head side of the boom cylinder 8bmc via the left chamber of the solenoid valve 89 and solenoid valve 49, the boom-up operation can be accelerated. It is possible to improve the work of.

  In addition, when the bucket-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, and the pressure Can be controlled separately. In particular, by closing the electromagnetic valve 89 together with the electromagnetic valve 74, a high pressure in the bucket cylinder 8bkc can be secured.

  In addition, since the inter-pump solenoid valve 102 is provided in the inter-pump communication passage 101, when the boom-up flow rate is not required, the solenoid valve 102 is opened to reduce the working fluid discharge amount from the boom assist pump 84as. The working fluid supply amount from one main pump 14A can be merged, so that the workability can be improved, and by closing the electromagnetic valve 102, the working fluid supply amount to the boom cylinder 8bmc can be secured.

  In addition to the solenoid valve 72 between the stick and boom, the solenoid valve 74 between the bucket and stick, the solenoid valve 89 between the bucket and boom, and the solenoid valve 102 between the pumps, the communication passage solenoid valve 98 is opened and closed. Thus, the degree of freedom of combination between the circuits that replenish the working fluid is increased, and various operation pattern requirements can be easily met.

  The boom control circuit 45 can be completely disconnected from the main pumps 17A and 17B by closing the solenoid valves 72, 89, and 102 to the shut-off position.

  As described above, the combination of the switching states of the solenoid valves 72, 74, 89, 98, and 102 increases the degree of freedom of the combination and makes the system configuration flexible. Further, the fuel efficiency of the engine 11 can be improved by the hybrid system.

1 is a circuit diagram showing an embodiment of a turning drive device according to the present invention. It is a side view of the working machine equipped with the drive device for turning same as the above.

Explanation of symbols

4swh swing motor
23 Battery
92, 93 closed circuit
94 Solenoid valve as directional control valve
95 Swing pump / motor
96 Electric motor / generator for turning
97 Outside passage
98 Connection passage solenoid valve
99 Working fluid replenishment pump as working fluid replenishment means

Claims (2)

A swivel motor that swivels a load in response to supply of a working fluid;
A swivel pump motor that functions as a fluid pressure motor by the working fluid discharged from the swivel motor and that functions as a pump that is connected to the swivel motor in a closed circuit and supplies the working fluid to the swivel motor;
A directional control valve having a neutral position and a directional control position for closing between the swing pump motor and the swing motor;
Driven by a swing pump / motor that functions as a fluid pressure motor during swing braking of the load, functions as a generator, and also functions as a motor that receives power and drives the swing pump / motor as a pump. A generator,
A capacitor that stores electric power supplied from the electric motor / generator for turning that functions as the generator and supplies electric power to the electric motor / generator for turning that functions as an electric motor;
An external communication passage for supplying a working fluid to the outside of the swivel system from a closed circuit between the swivel pump motor and the direction control valve;
A communication passage solenoid valve that is disposed in a connection passage outside the system and that is displaced between a position that enables supply of working fluid to the outside of the swivel system and a position that blocks the flow;
A swivel drive device comprising a working fluid replenishing means for replenishing a working fluid to a closed circuit between a swiveling pump motor and a directional control valve. The turning drive device according to claim 1, wherein the working fluid replenishing means is a working fluid replenishing pump.

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