JP2011075082A - Fluid pressure control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase efficiency of an assist regenerative mechanism by suppressing occurrence of drag loss due to an assist pump during driving of a regenerative motor, and drag loss due to the regenerative motor during driving of the assist pump. <P>SOLUTION: A fluid pressure control device includes a planetary gear 1 with three rotation elements of first, second, and third rotation elements 11, 12, and 13; the regenerative motor 2 whose rotary shaft is connected to the first rotation element 11; the assist pump whose rotary shaft is connected to the second rotary shaft 12; a motor generator 4 whose rotary shaft is connected to the third rotation element 13; a capacitor 5 for storing the power generated by the motor generator; and a rotation restriction means for restricting the rotations of the first and second rotation elements 11 and 12. By restricting the rotation of the second rotary element, the first rotation element is functioned as an input element, and the third rotation element 13 is functioned as an output element. Thereby, the motor generator is driven by the regenerative motor 2 so as to recover the energy of a working fluid discharged from an actuator. By restricting the rotation of the first rotation element, the third rotation element is functioned as an input element, and the second rotation element is functioned as an output element. Thereby, a hydraulic assist pump 3 is driven by the motor generator so as to assist the drive of the actuator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fluid pressure control device for controlling a hydraulic working device.

  As a fluid pressure control device for controlling hydraulic work equipment such as a hydraulic excavator, Patent Document 1 selectively supplies hydraulic fluid to a work machine system actuator, a travel system actuator, and a work machine system or a travel system actuator. The first pump and the second pump, the variable capacity regenerative motor connected to the return path when inertial energy or potential energy is applied to the actuator of the work machine system, and the regenerative motor rotating together. In addition, a variable displacement type assist pump that joins hydraulic oil to one or both of the first pump and the second pump, a motor generator that rotates integrally with the regenerative motor and the assist pump, and electric power generated by the motor generator And a power storage unit for storing power.

JP 2007-327527 A

  However, in the above-described fluid pressure control device, the regenerative motor and the assist pump rotate together with the motor generator, so that the assist pump also rotates together when generating power by rotating the motor generator with the regenerative motor. At this time, the capacity of the assist pump is controlled so that the displacement of the assist pump is reduced to zero and the loss is minimized, but there is a problem that drag loss of the assist pump occurs even if the displacement of the assist pump is reduced to zero. It was. Similarly, when the assist pump is rotated by the motor generator, the regenerative motor rotates together. At this time, the capacity of the regenerative motor is controlled so that the loss is minimized by reducing the displacement of the regenerative motor to zero, but there is a problem in that a drag loss of the regenerative motor occurs even if the displacement is zero. It was.

  The present invention has been made paying attention to such problems, and it is an object of the present invention to suppress the occurrence of drag loss due to the assist pump when the regenerative motor is driven, and to suppress the occurrence of drag loss due to the regenerative motor when the assist pump is driven. And

  The present invention relates to an actuator driven by a working fluid supplied from a main pump, a control valve for switching supply / discharge of the working fluid to / from the actuator, recovers the energy of the working fluid discharged from the actuator, and drives the actuator. An assist regeneration mechanism comprising: an assist regeneration mechanism, wherein the assist regeneration mechanism includes three rotation elements of a first rotation element, a second rotation element, and a third rotation element, and rotation of one rotation element The planetary gear mechanism that allows one of the remaining two rotating elements to function as an input element and the other as an output element, and a rotating shaft is connected to the first rotating element and is driven by the working fluid discharged from the actuator. Is connected to the working fluid discharged from the main pump. An assist pump that discharges the working fluid for generating the motor, a motor generator having a rotating shaft connected to the third rotating element, a capacitor that stores electric power generated by the motor generator, and a first that restricts rotation of the first rotating element. A rotation restricting means and a second rotation restricting means for restricting the rotation of the second rotating element, and restricting the rotation of the second rotating element to restrict the first rotating element to the input element and the third rotating element to the output element. The motor generator is driven by the regenerative motor, the energy of the working fluid discharged from the actuator is recovered, and the rotation of the first rotating element is restricted to restrict the rotation of the first rotating element to the second rotating element. The hydraulic assist pump is driven by a motor generator by functioning as an output element to assist the drive of the actuator.

  According to the present invention, the regenerative motor is connected to the first rotating element of the planetary gear mechanism, the assist pump is connected to the second rotating element, and the motor generator is connected to the third rotating element.

  When power generation by the motor generator is performed, the motor generator is driven by the regenerative motor by restricting the rotation of the second rotating element. Therefore, since the assist pump does not rotate when the regenerative motor is driven, the occurrence of drag loss due to the assist pump can be suppressed.

  Further, when driving the assist pump, the assist pump is driven by the motor generator by restricting the rotation of the first rotating element. Therefore, since the regenerative motor does not rotate when the assist pump is driven, the occurrence of drag loss due to the regenerative motor can be suppressed.

It is a schematic side view of the excavation attachment of a hydraulic excavator. It is a schematic block diagram of a fluid pressure control apparatus. It is a schematic block diagram of the assist regeneration mechanism by 1st Embodiment. It is a schematic block diagram of the assist regeneration mechanism by 2nd Embodiment. It is a schematic block diagram of the assist regeneration mechanism by other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
The fluid pressure control device controls the operation of a hydraulic working device such as a hydraulic excavator. In this embodiment, the fluid pressure control device controls the expansion / contraction operation of the boom cylinder 104 that drives the boom (load) 101 of the hydraulic excavator shown in FIG. The case where it does is demonstrated.

  FIG. 1 is a schematic side view of a excavator attachment 100 of a hydraulic excavator.

  The excavation attachment 100 includes a boom 101, an arm 102, and a bucket 103 for performing excavation work and the like, and these are driven by a boom cylinder 104, an arm cylinder 105, and a bucket cylinder 106, which are actuators. Each of the boom cylinder 104, the arm cylinder 105, and the bucket cylinder 106 is a hydraulic cylinder.

  FIG. 2 is a schematic configuration diagram of the fluid pressure control apparatus according to the present embodiment.

  The boom cylinder 104 is partitioned into a rod-side pressure chamber 104a and a bottom-side pressure chamber 104b by a piston rod 107 that slidably moves within the boom cylinder 104. The piston rod 107 is connected to the boom 101, and the boom 101 is driven when the piston rod 107 moves in the boom cylinder 104.

  The main pump 108 and the pilot pump 109, which are hydraulic sources, are driven by an engine (not shown) mounted on a hydraulic excavator and discharge hydraulic oil (working fluid). The engine is operated at a predetermined rotational speed and load with good operating efficiency.

  The hydraulic oil discharged from the main pump 108 is supplied to a main control valve (control valve) 110 that switches between supplying and discharging hydraulic oil to and from the boom cylinder 104. The main pump 108 and the main control valve 110 are connected by a main passage 111. The hydraulic oil discharged from the assist pump 3 of the assist regeneration mechanism 10 (see FIG. 3) described later is guided to the main passage 111 through the sub passage 31.

  The main control valve 110 and the rod side pressure chamber 104a of the boom cylinder 104 are connected by a first passage 112, and the main control valve 110 and the bottom side pressure chamber 104b of the boom cylinder 104 are connected by a second passage 113. . Connected to the second passage 113 is a return passage 21 through which hydraulic oil discharged from the bottom pressure chamber 104b of the boom cylinder 104 flows to drive the regeneration motor 2 of the assist regeneration mechanism 10 (see FIG. 3) described later. The

  The main control valve 110 is operated by a pilot pressure supplied from the pilot pump 109 to the pilot chambers 110a and 110b. Control of the pilot pressure supplied to the pilot chambers 110a and 110b is performed by the controller 114 controlling the pilot solenoid valve 115 based on a lever operation by the crew of the excavator.

  When the pilot pressure is supplied to the pilot chamber 110a, the main control valve 110 is switched to the position a, the hydraulic oil is supplied from the main pump 108 to the rod side pressure chamber 104a via the first passage 112, and the bottom The hydraulic oil in the side pressure chamber 104 b is discharged to the tank T through the second passage 113. As a result, the piston rod 107 in the boom cylinder 104 moves downward in FIG. 2, that is, the boom cylinder 104 contracts, and the boom 101 descends in the direction of the arrow 121 shown in FIG.

  When the pilot pressure is supplied to the pilot chamber 110b, the main control valve 110 is switched to the position b, and hydraulic oil is supplied from the main pump 110 to the bottom pressure chamber 104b through the second passage 113. The hydraulic oil in the rod side pressure chamber 104 a is discharged to the tank T through the first passage 112. As a result, the piston rod 107 in the boom cylinder 104 moves upward in FIG. 2, that is, the boom cylinder 104 extends, and the boom 101 rises in the direction of the arrow 122 shown in FIG.

  Further, when the pilot pressure is not supplied to the pilot chambers 110a and 110b, the main control valve 110 is switched to the position c, the supply and discharge of the hydraulic oil to the boom cylinder 104 is shut off, and the boom 101 is kept stopped.

  Thus, the main control valve 110 has three switching positions: a contracted position “a” for contracting the boom cylinder 104, an extended position “b” for extending the boom cylinder 104, and a blocking position “c” for holding the load of the boom cylinder 104.

  Here, when the control valve 6 is switched to the shut-off position c to stop the movement of the boom 101, the piston rod 107 in the boom cylinder 104 is moved to the lower side in FIG. A force to move, that is, a force to contract the boom cylinder 104 is applied. Thus, in the boom cylinder 104 that drives the boom 101, the bottom-side pressure chamber 104b is a load-side pressure chamber in which the load pressure acts when the control valve is in the cutoff position c. On the other hand, in the arm cylinder 105 that drives the arm 102, the rod side pressure chamber 104a is a load side pressure chamber.

  In the following description, a decrease in load means a change in the direction in which the volume of the load side pressure chamber decreases, and an increase in load means a change in the direction in which the volume of the load side pressure chamber increases. Point to. Therefore, in the case of the boom cylinder 104, the decrease in load means that the boom cylinder 104 contracts and the boom 101 descends, and the increase in load means that the boom cylinder 104 extends and the boom 101 rises. Point to.

  In the present embodiment, the fluid pressure control device regenerates the hydraulic energy of the hydraulic oil discharged from the bottom side pressure chamber 104b when the boom cylinder 104 is contracted as electrical energy as necessary, and the boom cylinder 104. An assist regenerative mechanism 10 that can perform an assist that provides an assisting force as necessary when the arm is extended is connected.

  FIG. 3 is a schematic configuration diagram of the assist regeneration mechanism 10 connected to the fluid pressure control device.

  The assist regeneration mechanism 10 is configured by connecting a regenerative motor 2, an assist pump 3, and a motor generator 4 to the planetary gear 1. Hereinafter, each component will be described in detail.

  The planetary gear 1 includes three rotating elements, a ring gear (first rotating element) 11, a pinion gear carrier (second rotating element) 12, and a sun gear (third rotating element) 13. One of these three rotating elements is included. By limiting the rotation, the transmission can function one of the remaining two rotating elements as an input element and the other as an output element.

  In the planetary gear 1, a sun gear 13, which is an external gear, is disposed at the center, and a ring gear 11 having inner teeth 11 a and outer teeth 11 b is disposed around the sun gear 13. Several pinion gears 14 that are external gears are arranged between the sun gear 13 and the ring gear 11, and each pinion gear 14 meshes with the sun gear 13 and the internal teeth 11 a of the ring gear 11. Each pinion gear 14 can rotate (revolve) around the sun gear 13 simultaneously with rotation (spinning) individually. Each pinion gear 14 is grouped by a pinion gear carrier 12. When each pinion gear 14 revolves around the sun gear 13, the pinion gear carrier 12 rotates.

  The sun gear 13 of the planetary gear 1 is connected to a rotation shaft 41 of the motor generator 4 (hereinafter referred to as “motor generator rotation shaft”). A battery 5 is connected to the motor generator 4 via an inverter 6 while storing electric power generated by the motor generator 4 and supplying electric power to the motor generator 4 for driving. The battery 5 is provided with a charge amount detection sensor 51 that detects the battery charge amount, and a signal from the charge amount detection sensor 51 is input to the controller 114.

  The regenerative motor 2 is a fixed displacement hydraulic motor, and is driven by hydraulic oil that has been discharged from the bottom pressure chamber 104 b of the boom cylinder 104 and has flowed through the return passage 21. By restricting the rotation of the pinion gear carrier 12 when the regenerative motor 2 is driven, the ring gear 11 functions as an input element and the sun gear 13 functions as an output element, so that the motor generator 4 can generate electric power.

  The return passage 21 is provided with a return control valve 22 that switches between supply and discharge of hydraulic fluid to the regenerative motor 2. The return control valve 22 has a communication position d for supplying hydraulic oil to the regenerative motor 2 according to the pilot pressure supplied from the pilot pump 109 to the pilot chamber 22a, and a shut-off for stopping the supply of hydraulic oil to the regenerative motor 2. Switch to position e. Control of the pilot pressure supplied to the pilot chamber 22a is performed by the controller 114 controlling the pilot solenoid valve 23 based on a lever operation by the crew of the excavator.

  A counter gear 25 that meshes with the external teeth 11b of the ring gear 11 is connected to a rotating shaft (hereinafter referred to as "regenerative motor rotating shaft") 24 of the regenerative motor 2, and a hydraulic disc brake (including a disc 26a and a pad 26b). First rotation restricting means) 26 is provided.

  The hydraulic brake disc 26 presses the pad 26b against the disc 26a by supplying hydraulic pressure to the oil chamber 26c, thereby restricting the rotation of the regenerative motor rotating shaft 24 and preventing the regenerative motor rotating shaft 24 from rotating. Supply of hydraulic pressure to the oil chamber 26c may be performed by either the main pump 108 or the pilot pump 109, and control of the hydraulic pressure supplied to the oil chamber 26c is performed by the controller 114 based on lever operation by the crew of the hydraulic excavator. This is done by controlling a solenoid valve or the like.

  The assist pump 3 is a fixed displacement hydraulic pump. The assist pump 3 is driven by the motor generator 4 when the rotation of the ring gear 11 is restricted and the sun gear 13 functions as an input element and the pinion gear carrier 12 as an output element, and hydraulic oil is supplied to the main path 111 via the sub-path 31. Supply.

  The sub passage 31 is provided with a sub control valve 32 that switches supply and discharge of hydraulic oil to and from the main passage 111. The sub control valve 32 has a communication position f for supplying hydraulic oil to the main passage 111 according to the pilot pressure supplied from the pilot pump 109 to the pilot chamber 32a, and a cutoff for stopping the supply of hydraulic oil to the main passage 111. Switch to position g. Control of the pilot pressure supplied to the pilot chamber 32a is performed by the controller 114 controlling the pilot solenoid valve 33 based on a lever operation by the crew of the excavator.

  A pinion gear carrier 12 is connected to a rotating shaft (hereinafter referred to as “assist pump rotating shaft”) 34 of the assist pump 3, and a hydraulic disc brake (second rotation restricting means) 35 including a disc 35 a and a pad 35 b. Is provided.

  The hydraulic brake disc 35 presses the pad 35b against the disc 35a by supplying hydraulic pressure to the oil chamber 35c, thereby restricting the rotation of the regenerative motor rotating shaft 34 and preventing the regenerative motor rotating shaft 34 from rotating. Supply of hydraulic pressure to the oil chamber 35c may be performed by either the main pump 108 or the pilot pump 109, and control of the hydraulic pressure supplied to the oil chamber 35c is performed by the controller 114 based on lever operation by the crew of the hydraulic excavator. This is done by controlling a solenoid valve or the like.

  Next, the operation of the fluid pressure control apparatus according to the present embodiment will be described with reference to FIGS.

  First, regeneration by the assist regeneration mechanism 10 performed as necessary when the load is lowered will be described.

  When a lever operation for contracting the boom cylinder 104 is performed by the crew of the hydraulic excavator, the main control valve 110 is switched to the contracted position a, and hydraulic oil is supplied to the rod side pressure chamber 104a and from the bottom side pressure chamber 104b. Hydraulic oil is discharged.

  At this time, for example, when the battery charge amount is smaller than the full charge amount, the return control valve 22 is switched to the communication position d as necessary, and a part of the hydraulic oil discharged from the bottom pressure chamber 104b is returned to the return passage. It is supplied to the regenerative motor 2 through 21. At the same time, the hydraulic disc brake 35 of the assist pump 3 is operated so that the assist pump rotating shaft 34 cannot be rotated to fix the pinion gear carrier 12, and the ring gear 11 functions as an input element and the sun gear 13 functions as an output element.

  Thereby, the counter gear 25 is rotated by the regenerative motor 2, and the ring gear 11 meshing with the counter gear 25 is rotated. When the ring gear 11 rotates, the pinion gear carrier 12 is fixed, so that the pinion gear 14 rotates without revolving around the sun gear 13. As a result, the sun gear 13 rotates in the direction opposite to the rotation of the ring gear 11 to rotate the motor generator rotating shaft 41, and power generation by the motor generator 4 is performed.

  On the other hand, when the return control valve 22 is switched to the cutoff position e as necessary, for example, when the battery charge amount reaches the full charge amount, all the hydraulic oil discharged from the bottom side pressure chamber 104b is second. It is discharged to the tank T through the passage 113, and regeneration is stopped.

  Next, assist by the assist regeneration mechanism 10 that is performed as necessary when the load increases will be described.

  When the lever of the hydraulic excavator performs a lever operation to extend the boom cylinder 104, the operation is switched to the position of the main control valve 110, the hydraulic oil is supplied to the bottom side pressure chamber 104b, and the hydraulic oil in the rod side pressure chamber 104a is supplied. It is discharged to the tank T through the first passage 112.

  Here, the engine is operated at a predetermined rotational speed and load with good operating efficiency. Accordingly, there is a case where the flow rate of the hydraulic oil supplied to the bottom side pressure chamber 104b is insufficient with only the discharge flow rate by the driving force of the engine, for example, when it is desired to extend the boom cylinder 104 quickly. In such a case, the assist regeneration mechanism 10 assists.

  Specifically, the hydraulic disc brake 26 of the regenerative motor 2 is operated to fix the ring gear 11 so that the regenerative motor rotating shaft 24 cannot rotate, and the sun gear 13 functions as an input element and the pinion gear carrier 12 functions as an output element. . At the same time, the sub-control valve 32 is switched to the communication position f to drive the motor generator 4.

  Thereby, the sun gear 13 is rotated by the motor generator 4. When the sun gear 13 rotates, the ring gear 11 is fixed, so that the pinion gear 14 revolves around the sun gear 13 while rotating. As a result, the pinion gear carrier 12 rotates to rotate the assist pump rotating shaft 34, and hydraulic oil is discharged from the assist pump 3. The hydraulic oil discharged from the assist pump 3 joins the main passage 111 via the sub passage 31 and gives an auxiliary force when the boom cylinder 104 is extended.

  According to the embodiment described above, the assist regeneration mechanism 10 is configured by connecting the motor generator 4 to the sun gear 13 of the planetary gear 1, the regenerative motor 2 to the ring gear 11, and the assist pump 3 to the pinion gear carrier 12. Then, during regeneration, the rotation of the pinion gear carrier 12 is regulated and the motor generator 4 is driven by the regeneration motor 2, and during assist, the rotation of the ring gear 11 is regulated and the assist pump 3 is driven by the motor generator 4.

  Thus, since the rotation of the pinion gear carrier 12 is restricted during regeneration, the assist pump rotating shaft 34 does not rotate. Therefore, even if the regenerative motor 2 rotates during regeneration, the assist pump rotating shaft 34 is not rotated by the rotation. Further, since the rotation of the ring gear 11 is restricted during the assist, the regenerative motor rotating shaft 24 does not rotate. Therefore, even if the assist pump rotating shaft 34 rotates during assist, the regenerative motor rotating shaft 24 is not rotated by the rotation.

  Here, in the assist regeneration mechanism 10 that selectively uses the hydraulic motor (regenerative motor 2) and the hydraulic pump (assist pump 3) as needed, when the hydraulic motor and the hydraulic pump are arranged coaxially, the hydraulic motor is used during regeneration and assist. And the hydraulic pump rotate together. Therefore, when the hydraulic motor and the hydraulic pump are fixed capacity type, there is a problem that no-load loss occurs. In order to solve this problem, it is necessary to make the hydraulic motor and the hydraulic pump variable displacement type and to control the other capacity to zero when one is driven. However, the variable capacity type has a problem that the cost is higher than the fixed capacity type, and even if the capacity is reduced to zero, there are structural movable parts, so that drag loss occurs and noise increases.

  On the other hand, according to the present embodiment, as described above, only the regenerative motor 2 can be driven during regeneration, and only the assist pump 3 can be driven during assist.

  Therefore, even if the regenerative motor 2 and the assist pump 3 are fixed-capacity types each having a low cost, there is no drag loss and driving noise caused by the assist pump 3 when the regenerative motor is driven. No drag loss and drive noise due to 2 occur.

  In addition, the fixed displacement hydraulic motor and hydraulic pump are low in cost because the structure is simpler than the variable displacement hydraulic motor and hydraulic pump. Therefore, the cost can be reduced as compared with the case where the assist regeneration mechanism is configured using a variable displacement hydraulic motor and a hydraulic pump.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in the rotation restricting means of the regenerative motor rotating shaft 24 and the assist pump rotating shaft 34. Hereinafter, the difference will be mainly described. In the following embodiments, the same reference numerals are used for the same functions as those in the first embodiment described above, and repeated descriptions are omitted as appropriate.

  FIG. 4 is a schematic configuration diagram of the assist regeneration mechanism 10 according to the present embodiment.

  The assist regeneration mechanism 10 according to this embodiment includes a rotation restriction valve 27 that restricts the rotation of the regeneration motor 2 in the return passage 21 on the hydraulic oil discharge side of the regeneration motor 2, and the sub passage 31 on the hydraulic oil discharge side of the assist pump 3. A rotation regulating valve 36 that regulates the rotation of the assist pump 3 is provided.

  The rotation regulating valve 27 is an electromagnetic valve, and is switched between a communication position h and a blocking position i by the controller 114. When the rotation restricting valve 27 is switched to the shut-off position i, the regenerative motor 2 cannot discharge the hydraulic oil, so that the regenerative motor 2 is restricted from rotating.

  The rotation restricting valve 36 is also an electromagnetic valve, and is switched between the communication position j and the blocking position k by the controller 114. When the rotation regulating valve 36 is switched to the shut-off position k, the assist pump 3 can no longer discharge the hydraulic oil, so that the rotation of the assist pump 3 is regulated.

  The rotation regulating valves 27 and 36 are each provided with a relief mechanism (not shown) for returning the hydraulic oil to the tank when the pressure is too high in the shut-off position.

  Also in the present embodiment described above, at the time of regeneration, the rotation of the assist pump rotating shaft 34 is restricted by switching the rotation restricting valve 36 to the cutoff position k, and only the regenerative motor 2 can be driven. Similarly, at the time of assist, the rotation restricting valve 27 is switched to the cutoff position i to restrict the rotation of the regenerative motor rotating shaft 24 and only the assist pump 3 can be driven. Therefore, the same effect as that of the first embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, as shown in FIG. 5, if the motor generator 4 is provided with a hydraulic disc brake 42 that restricts the rotation of the motor generator rotating shaft 41, the rotation of the motor generator rotating shaft 41 is restricted and the ring gear 11 is used as the input element and the pinion gear. The assist pump 3 can be directly driven by the regenerative motor 2 with the carrier 12 functioning as an output element. Thereby, even when the charge amount of the battery 5 reaches the full charge amount or when the charging efficiency for the battery 5 is poor, the hydraulic energy of the hydraulic oil discharged from the boom cylinder 104 is wasted. It can be used effectively. The hydraulic disc brake 42 may have the same configuration as the hydraulic disc brakes 26 and 35 described above.

  In each of the above embodiments, the hydraulic cylinder has been described as an example of the actuator. However, the present invention is not limited to this, and may be a traveling motor or a turning motor of a construction machine such as a hydraulic excavator or a work machine.

  In each of the above embodiments, the motor generator 4 is connected to the sun gear 13 of the planetary gear 1, the regenerative motor 2 is connected to the ring gear 11, and the assist pump 3 is connected to the pinion gear carrier 12. However, the motor generator 4 and the regenerative motor 2 are connected to any rotating element. And whether to connect the pinion gear carrier 12 can be freely determined according to the gear ratio of the planetary gear 1 and the rotational directions (forward and reverse) of the input element and the output element.

  In each of the above embodiments, the hydraulic disc brakes 26 and 35 are used as means for restricting the rotation of the regenerative motor 2 and the assist pump 3, but the invention is not limited to the hydraulic type, and a mechanical or electric disc is used. A brake may be used.

  Further, in each of the above embodiments, the assist regeneration mechanism 10 is applied to the fluid pressure control device that drives only the boom cylinder 104 in order to facilitate understanding of the invention. However, the boom cylinder 104, the arm cylinder 105, the bucket cylinder 106, etc. You may apply to the fluid-pressure control apparatus which drives a some actuator.

1 planetary gear 2 regenerative motor 3 assist pump 4 motor generator 5 battery (capacitor)
10 Assist regeneration mechanism 11 Ring gear (first rotating element)
12 Pinion gear carrier (second rotating element)
13 Sun gear (third rotating element)
26 Hydraulic disc brake (first rotation restricting means)
35 Hydraulic disc brake (second rotation restricting means)
42 Hydraulic disc brake (third rotation restricting means)
104 Boom cylinder (actuator)
108 Main pump 110 Main control valve (control valve)

Claims (5)

An actuator driven by a working fluid supplied from a main pump;
A control valve for switching supply and discharge of the working fluid to and from the actuator;
An assist regeneration mechanism for recovering the energy of the working fluid discharged from the actuator and assisting the driving of the actuator;
A fluid pressure control device comprising:
The assist regeneration mechanism is
Three rotation elements of a first rotation element, a second rotation element, and a third rotation element are provided, and by restricting the rotation of one rotation element, one of the remaining two rotation elements is an input element and the other is an output element Planetary gears to function as
A regenerative motor having a rotating shaft connected to the first rotating element and driven by a working fluid discharged from the actuator;
An assist pump having a rotating shaft connected to the second rotating element and discharging a working fluid for joining the working fluid discharged from the main pump;
A motor generator having a rotating shaft connected to the third rotating element;
A battery for storing electric power generated by the motor generator;
First rotation restricting means for restricting rotation of the first rotating element;
Second rotation restricting means for restricting rotation of the second rotating element;
Including
By restricting the rotation of the second rotating element, the first rotating element functions as an input element, the third rotating element functions as an output element, the motor generator is driven by the regenerative motor, and discharged from the actuator The energy of the working fluid is collected in the capacitor,
By restricting the rotation of the first rotating element, the third rotating element functions as an input element, the second rotating element functions as an output element, the hydraulic generator pump is driven by the motor generator, and the actuator is driven. To assist,
A fluid pressure control device. The assist regeneration mechanism is
Including third rotation restricting means for restricting rotation of the third rotating element;
By restricting the rotation of the third rotating element, the first rotating element functions as an input element, the second rotating element functions as an output element, the assist pump is driven by the regenerative motor, and the actuator is discharged from the actuator. Assisting the drive of the actuator by the energy of the working fluid;
The fluid pressure control apparatus according to claim 1. The regenerative motor is a fixed capacity hydraulic motor, and the assist pump is a fixed capacity hydraulic pump.
The fluid pressure control apparatus according to claim 1 or 2, wherein The first rotation restriction means and the second rotation restriction means stop the rotation of the rotation shafts of the regeneration motor and the assist pump by pressing a pad against a disk provided on the rotation shaft of the regeneration motor and the assist pump. Disc brake,
The fluid pressure control apparatus according to any one of claims 1 to 3, wherein The first rotation restricting means and the second rotation restricting means are provided in a working fluid discharge side oil passage of the regenerative motor and the assist pump, and the working fluid discharge side oil passage is switched from a communication state to a cut-off state. It is a valve that can
The fluid pressure control apparatus according to any one of claims 1 to 3, wherein

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