JP2019052040A - Hydraulic driving device for crane - Google Patents

Abstract

To improve the operability of a crane.SOLUTION: A hydraulic driving device for a crane includes an engine (1), a hydraulic pump (2), a hydraulic motor (3), a winch drum (13), a hydraulic pump motor (14), an accumulator (15), an operation device (7) for generating a pilot pressure, a first regulator (3a) for controlling the tilting of the hydraulic pump in accordance with the pilot pressure, and a second regulator (14a) for controlling the tilting of the hydraulic pump motor in accordance with the pilot pressure. The pilot pressure is input to the first regulator and the second regulator through a conduit line.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crane hydraulic drive apparatus having an energy regeneration system.

  As a prior art of a hydraulic drive device for a crane equipped with an energy regeneration system, for example, Patent Document 1 discloses, for example, “a hydraulic motor that drives a winch by pressure oil from a hydraulic pump, and a kinetic energy of the winch at the time of unloading ( A hydraulic drive device that assists in driving the winch by reusing the pressure oil accumulated in the accumulator.

Japanese Patent No. 5324872

  A delicate operability is required for lifting and lowering a crane load. In a hydraulic drive circuit of a crane equipped with an accumulator as in Patent Document 1, the torque of a hydraulic motor that drives a winch according to the accumulated pressure of the accumulator. However, the problem remains in terms of operability.

  Accordingly, an object of the present invention is to improve the operability of a crane provided with an accumulator that converts kinetic energy of a winch into hydraulic energy and accumulates it.

  In order to solve the above problems, a representative present invention includes an engine, a hydraulic pump driven by the engine, a hydraulic motor driven by pressure oil discharged from the hydraulic pump, and a rotating shaft of the hydraulic motor. The winch drum connected to the hydraulic pump, the hydraulic pump motor connected to the rotating shaft of the hydraulic motor, and the pressure oil discharged from the hydraulic pump motor are accumulated, and the accumulated pressure oil is supplied to the hydraulic pump motor An accumulator that operates, an operating device that generates a pilot pressure according to an operation amount, a first regulator that controls the tilt of the hydraulic pump, and a second regulator that controls the tilt of the hydraulic pump motor. In the crane hydraulic drive device, the pilot pressure is configured to be input to the first regulator and the second regulator via a pipeline. Characterized in that was.

  ADVANTAGE OF THE INVENTION According to this invention, the operativity of the crane provided with the accumulator which converts and accumulate | stores the kinetic energy of a winch into hydraulic energy can be improved. Note that problems, configurations, and effects other than those described above will be clarified in the following description of embodiments.

1 is an external side view of a crane to which the present invention is applied. 1 is a hydraulic circuit diagram of a hydraulic drive device for a crane according to a first embodiment. It is a figure which shows the relationship between pilot pressure and torque. It is a figure which shows the relationship between an accumulator pressure and a torque. It is a figure which shows the regulator structure of a hydraulic motor. It is a figure which shows the regulator structure of a hydraulic pump motor. It is a hydraulic circuit diagram of the hydraulic drive device of the crane which concerns on 2nd Embodiment. FIG. 2A is a hardware configuration diagram of a controller, and FIG. 2B is a functional block diagram of the controller.

“First Embodiment”
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external side view of a crane including a hydraulic drive device according to a first embodiment of the present invention. A crane 100 shown in FIG. 1 includes a traveling body 101, a revolving body 103 that is turnable on the traveling body 101, and a boom 104 that is pivotally supported by the revolving body 103. The revolving structure 103 is equipped with a hoisting drum 13 that is a winch drum for hoisting and a hoisting drum 106 that is a winch drum for hoisting a boom.

  A hoisting rope 105 a is wound around the hoisting drum 13, and the hoisting rope 105 a is wound or fed out by the rotation of the hoisting drum 13, and the hook 110 moves up and down. A hoisting rope 106 a is wound around the hoisting drum 106, and the hoisting rope 106 a is wound or fed out by the rotation of the hoisting drum 106, and the boom 104 is raised and lowered.

  FIG. 2 is a hydraulic circuit diagram of the hydraulic drive device for the crane according to the first embodiment of the present invention. In FIG. 2, a hydraulic circuit for driving a hydraulic motor for undulation is not shown. As shown in FIG. 2, the crane hydraulic drive system includes an engine 1, a variable displacement main pump (hydraulic pump) 2, a fixed displacement pilot pump 5, and a hydraulic motor that rotationally drives a hoisting drum 13. 3, an accumulator 15 that accumulates pressure oil, and a pump motor (hydraulic pump motor) 14 that assists the rotation of the hydraulic motor 3 and supplies pressure oil to the accumulator 15. The hydraulic motor 3 is a variable displacement type, and its tilt is controlled by a hydraulic motor regulator (first regulator) 3a described later. The pump motor 14 is also of a variable capacity type, and its tilt is controlled by a pump motor regulator (second regulator) 14a described later.

  The main pump 2 and the pilot pump 5 are driven by the engine 1 and discharge the hydraulic oil in the tank 11 as pressure oil. For example, a swash plate type piston pump is used as the main pump 2, and a discharge flow rate of the main pump 2 is controlled by controlling a tilt of the swash plate by a regulator (not shown). The pressure oil discharged from the main pump 2 flows through the pipeline 70 and its direction and flow rate are controlled by the direction control valve 4. The directional control valve 4 is a center bypass type, and when the directional control valve 4 is in the neutral position, the pressure oil from the main pump 2 is returned to the tank 11 via the pipe line 72. When the direction control valve 4 is switched to the left position, the main pump 2 communicates with the raising pipe (hydraulic pipe) 9b. On the other hand, when the directional control valve 4 is switched to the right position, the main pump 2 communicates with the lowering pipe (hydraulic pipe) 9a. Then, the pressure oil discharged from the main pump 2 and flowing through the down line 9 a or the up line 9 b via the direction control valve 4 is supplied to the hydraulic motor 3. When the hydraulic motor 3 is rotated by the supplied pressure oil, the hoisting drum 13 is rotated.

  The pressure oil discharged from the pilot pump 5 flows through the pipe 71 and is introduced into the operation lever (operation device) 7, and a pilot pressure corresponding to the operation amount of the operation lever 7 is generated. When the operation lever 7 is operated, the pilot pressure acts on the pressure chambers 4 a and 4 b of the direction control valve 4. With this pilot pressure, the directional control valve 4 is switched from the neutral position to the left position or the right position. Specifically, when the operation lever 7 is tilted to the left in FIG. 2, the pilot pressure acts on the pressure chamber 4a on the left side of the direction control valve 4, and the position of the direction control valve 4 is switched from the neutral position to the left position. As a result, the pressure oil from the main pump 2 flows through the raising pipe 9b through the direction control valve 4 and is supplied to the hydraulic motor 3, and the hoisting drum 13 rotates in the hoisting direction for hoisting the hoisting rope 105a. .

  On the other hand, when the operation lever 7 is tilted to the right in FIG. 2, the pilot pressure acts on the pressure chamber 4b on the right side of the direction control valve 4, and the position of the direction control valve 4 is switched from the neutral position to the right position. As a result, the pressure oil from the main pump 2 flows through the lower pipe 9a via the direction control valve 4 and is supplied to the hydraulic motor 3, and the hoisting drum 13 rotates in the lowering direction for feeding the hoisting rope 105a. .

  The pump motor 14 is mechanically connected to the rotating shaft of the hydraulic motor 3. When the hydraulic motor 3 rotates in the lowering direction, the pump motor 14 functions as a pump, sucks the hydraulic oil in the tank 11 from the pipe 73, discharges the pressure oil to the accumulator 15 through the pipe 74, Accumulated pressure oil is accumulated in the accumulator 15. That is, the pump motor 14 has a function of converting the kinetic energy of the hydraulic motor 3 into hydraulic energy and storing it in the accumulator 15. On the other hand, when the hydraulic motor 3 rotates in the winding direction, the pump motor 14 functions as a motor and rotates by the pressure oil accumulated in the accumulator 15 to assist the rotation of the hydraulic motor 3. In this case, the pressure oil accumulated in the accumulator 15 flows in the order of the pipe 74, the pump motor 14, and the pipe 73 and returns to the tank 11.

  In this hydraulic circuit, the maximum pressure of the main pump 2 is restricted to be lower than the set pressure of the main relief valve 8, and the highest pressure of the pilot pump 5 is restricted to be lower than the set pressure of the pilot relief valve 6. . A relief function for limiting the upper limit value of the pressure of the lowering pipe line 9a and a makeup function for preventing the lowering pipe line 9a from becoming negative pressure are provided on the pipe line 79 connecting the lowering pipe line 9a and the tank 11. A combination valve 10 is also provided. Further, a counter balance valve unit 12 that allows the flow of pressure oil from the hydraulic motor 3 to the direction control valve 4 is provided on the raising line 9b only when the pressure in the lowering line 9a exceeds a specified value. Further, in this hydraulic circuit, the high pressure side is selected from the two types of pilot pressures output from the operation lever 7, and the selected pilot pressure is branched from the hydraulic motor regulator 3 a and the pipeline 75 through the pipeline 75. A shuttle valve 16 is provided for output to the pump motor regulator 14 a through the pipeline 86.

  The high pressure side pilot pressure Pi selected by the shuttle valve 16 is input to the hydraulic motor regulator 3a via the pipe line 75, and both port pressures Pa and Pb of the hydraulic motor 3 are supplied to the pipe lines 76 and 77. Respectively. The pilot pressure Pi is input to the pump motor regulator 14 a via a pipe 86 branched from the pipe 75, and the accumulator pressure Pac is input from the pipe 78. The hydraulic motor regulator 3a and the pump motor regulator 14a are controlled according to the characteristics described below.

  FIG. 3 is a diagram showing torque distribution of the hydraulic motor 3 and the pump motor 14 with respect to the pilot pressure. FIG. 4 is a diagram showing torque distribution of the hydraulic motor 3 and the pump motor 14 with respect to the accumulator pressure when the pilot pressure is P1. As shown in FIG. 3, with respect to the pilot pressure Pi output from the shuttle valve 16, the hydraulic motor regulator 3a and the pump motor are used so that the torque T between the hydraulic motor 3 and the pump motor 14 increases while maintaining a constant ratio. The drive of the regulator 14a is controlled. Specifically, when the pilot pressure P1 is output from the shuttle valve 16, the drive of the hydraulic motor regulator 3a is controlled so that the torque of the hydraulic motor 3 becomes T1, and the torque of the pump motor 14 becomes T2. The drive of the pump motor regulator 14a is controlled. In the present embodiment, the torque ratio between the hydraulic motor 3 and the pump motor 14 is maintained at T1 / T2 regardless of the value of the pilot pressure Pi. That is, when the pilot pressure Pi input to the hydraulic motor regulator 3a and the pump motor regulator 14a increases, the torque of the hydraulic motor 3 and the pump motor 14 increases, but the hydraulic motor regulator 3a and the pump motor regulator 14a Since the pilot pressure is input to both, the torque ratio between the hydraulic motor 3 and the pump motor 14 is constant at T1 / T2 regardless of the value of the pilot pressure Pi. In addition, although the embodiment in which the characteristic of the torque T with respect to the pilot pressure Pi is linear has been described as an example, a quadratic curve or the like may be used.

  On the other hand, as shown in FIG. 4, the torque of the pump motor 14 is controlled to be a constant value regardless of the accumulator pressure Pac. Specifically, when the pilot pressure Pi = P1, the drive of the pump motor regulator 14a is controlled so that the torque of the pump motor 14 becomes T2 regardless of the value of the accumulator pressure Pac. Thus, in this embodiment, the torque of the pump motor 14 changes according to the value of the pilot pressure Pi. However, if the pilot pressure Pi is constant, the torque of the pump motor 14 changes the value of the accumulator pressure Pac. However, the drive of the pump motor regulator 14a is controlled to be constant.

  FIG. 5 is a hydraulic circuit diagram showing a detailed configuration of the hydraulic motor regulator 3a. As shown in FIG. 5, the hydraulic motor regulator 3 a is connected to the swash plate of the hydraulic motor 3, and makes the tilt of the hydraulic motor 3 variable, and the first hydraulic pressure of the first servo piston 37. A first spool 34 that controls the pressure in the chamber 40, a first servo piston 37, and a first link 38 are connected to each other, and operate in the axial direction (left-right direction in FIG. 5) in synchronization with the first servo piston 37. The sleeve 33, the first spring 32 that presses the first spool 34 in one axial direction (left direction in FIG. 5), and the first spool 34 is operated in the other axial direction (right direction in FIG. 5). A first piston 35, a second piston 36 for operating the first spool 34 in one axial direction, a first pressure chamber 39a for applying the pilot pressure Pi to the second piston 36, and a hydraulic pressure Motor 3 The second pressure chamber 39b for causing the high pressure side pressure of both the port pressures Pa and Pb to act on the first piston 35, and the low pressure side pressure of the both port pressures Pa and Pb of the hydraulic motor 3 are set to the second piston 36. A third pressure chamber 39c for acting on the pressure and a directional control valve 31 for selectively sending the pressure on the high pressure side to the second pressure chamber 39b with both port pressures Pa and Pb of the hydraulic motor 3 as inputs. Prepare. In FIG. 5, Pg is pressure oil supplied from the pilot pump 5, and Dr is drain. Reference numeral 80 denotes a pipe line connecting the direction switching valve 31 and the second pressure chamber 39b, reference numeral 81 denotes a pipe line connecting the direction switching valve 31 and the third pressure chamber 39c, and reference numeral 82 denotes the pilot pressure Pi as the first pressure. A pipe to be introduced into the chamber 39a, reference numeral 83 is a pipe for guiding the pressure oil from the pilot pump 5 to the rod chamber and the head chamber of the first servo piston 37, and reference numerals 84 and 85 are pipes connected to the drain.

  FIG. 6 is a circuit diagram showing a detailed configuration of the pump motor regulator 14a. As shown in FIG. 6, the pump motor regulator 14 a is connected to the swash plate of the pump motor 14 and makes the tilt of the pump motor 14 variable, and the second hydraulic pressure of the second servo piston 147. The second spool 144 that controls the pressure in the chamber 140, the second servo piston 147, and the second link 148 are connected to each other, and the second spool 144 operates in the axial direction (left-right direction in FIG. 6) in synchronization with the second servo piston 147. The sleeve 143, the second spring 142 that presses the second spool 144 in one axial direction (left direction in FIG. 6), and the second spool 144 is operated in the other axial direction (right direction in FIG. 6). A third piston 145 for moving the second spool 144 to one side in the axial direction, and a pilot pressure Pi acting on the fourth piston 146. It comprises a fourth pressure chamber 149a of the order, and a fifth pressure chamber 149b for applying a pressure Pac in the accumulator 15 to the third piston 145. In FIG. 6, Pg is pressure oil supplied from the pilot pump 5, and Dr is drain. Reference numeral 90 is a pipe line for introducing the accumulator pressure Pac into the fifth pressure chamber 149b, reference numeral 91 is a pipe line for introducing the pilot pressure into the fourth pressure chamber 149a, and reference numeral 92 is a second pipe for supplying the pressure oil from the pilot pump 5. Pipe lines leading to the rod chamber and the head chamber of the servo piston 147 and reference numerals 93 and 94 are pipes connected to the drain.

  With such a configuration, the pressure on the high pressure side of both port pressures Pa and Pb of the hydraulic motor 3 is selectively applied to the first piston 35 through the direction switching valve 31, and the pressure on the low pressure side is applied to the direction switching valve. 31 is selectively applied to the second piston 36. As a result, the hydraulic motor 3 is controlled to be tilted so as to have a constant torque with respect to the absolute value | Pa−Pb | of the difference between the two port pressures, and as the pilot pressure Pi is increased by the operation of the operation lever 7. The tilt is controlled so that the torque increases. Further, in the pump motor regulator 14a, the accumulator pressure Pac acts to move the second spool 144 in the direction opposite to the direction in which the second spool 144 moves due to the action of the pilot pressure Pi. The force for moving the second spool 144 in the direction of decreasing the turning angle increases. As a result, the tilt of the pump motor 14 is controlled so as to be a constant torque with respect to the accumulator pressure Pac, and the tilt is controlled so that the torque increases as the pilot pressure Pi increases by the operation of the operation lever 7. The

  Next, the operation of the hydraulic drive device according to this embodiment will be described.

(1) When the pressure of the accumulator 15 is low (the pressure accumulation amount is small) When the operation lever 7 is operated in the lowering direction (right side in FIG. 2), the direction control valve 4 is switched from the neutral position to the right position by the pilot pressure Pi. . Then, the main pump 2 and the lowering pipe line 9a are connected, and the torque in the lowering direction is generated in the hydraulic motor 3 by the pressure oil from the main pump 2. At this time, the pilot pressure Pi acts on the hydraulic motor regulator 3a and the pump motor regulator 14a, and the tilting of the hydraulic motor 3 and the pump motor 14 is controlled so that a constant torque ratio corresponding to the pilot pressure Pi is obtained. The pump motor 14 functions as a pump and accumulates pressure oil in the accumulator 15.

  When the operation lever 7 is operated in the winding direction (left side in FIG. 2), the direction control valve 4 is switched from the neutral position to the left position by the pilot pressure Pi. Then, the main pump 2 and the raising pipe line 9 b are connected, and the hydraulic motor 3 generates torque in the winding direction by the pressure oil from the main pump 2. At this time, the pilot pressure Pi acts on the hydraulic motor regulator 3a and the pump motor regulator 14a, and the tilting of the hydraulic motor 3 and the pump motor 14 is controlled so as to have a constant torque ratio according to the pilot pressure Pi. The pump motor 14 functions as a motor when pressure oil is supplied from the accumulator 15 and assists the rotation of the hydraulic motor 3.

(2) When the pressure of the accumulator 15 is high (the amount of accumulated pressure is large) When the operating lever 7 is operated in the lowering direction, the main pump 2 and the lower pipe 9a are connected, and torque in the lowering direction is generated in the hydraulic motor 3. . At this time, the pilot pressure Pi acts on the hydraulic motor regulator 3a, and the tilting of the hydraulic motor 3 is controlled so that the torque corresponds to the pilot pressure Pi. On the other hand, the pilot pressure Pi and the accumulator pressure Pac act on the pump motor regulator 14a, and are substantially the same as the torque of the pump motor 14 in the above (1) within the range of the torque of the pump motor 14 shown in FIG. Thus, the tilt of the pump motor 14 is controlled. The pressure oil discharged from the pump motor 14 is accumulated in the accumulator 15.

  When the operation lever 7 is operated in the winding direction, the main pump 2 and the lifting line 9b are connected, and a torque in the winding direction is generated in the hydraulic motor 3. At this time, the pilot pressure Pi acts on the hydraulic motor regulator 3a, and the tilting of the hydraulic motor 3 is controlled so that the torque corresponds to the pilot pressure Pi. On the other hand, the pilot pressure Pi and the accumulator pressure Pac act on the pump motor regulator 14a, and are substantially the same as the torque of the pump motor 14 in the above (1) within the range of the torque of the pump motor 14 shown in FIG. Thus, the tilt of the pump motor 14 is controlled. The pump motor 14 is driven by the pressure oil supplied from the accumulator 15 and assists the rotation of the hydraulic motor 3.

  As described above, according to the crane hydraulic drive apparatus according to the first embodiment, the torque of the hydraulic motor 3 and the pump motor 14 can be controlled at a constant torque ratio (T1 / T2) according to the pilot pressure Pi. The operability of the crane 100 is improved, and the lifting and lowering work of the crane 100 can be performed with high accuracy. Moreover, since the torque of the pump motor 14 can be controlled to be constant regardless of the pressure accumulation state of the accumulator 15, the operability of the crane 100 is further improved, which is suitable for the winch system of the crane 100.

“Second Embodiment”
Next, a hydraulic drive device according to a second embodiment of the present invention will be described. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. 7 is a hydraulic circuit diagram of a crane hydraulic drive apparatus according to the second embodiment of the present invention, FIG. 8A is a hardware configuration diagram of the controller, and FIG. 8B is a functional block diagram of the controller.

  In the second embodiment shown in FIG. 7, an electronically controlled hydraulic motor regulator 3a ′ and a pump motor regulator 14a ′ are used, and the drive of each regulator 3a ′, 14a ′ is controlled by an electrical signal from the controller 17. There is a feature in that. As shown in FIG. 7, in the second embodiment, pressure sensors 18a to 18e are provided. The pressure sensor (first pressure sensor) 18a detects the accumulator pressure Pac. The pressure sensors (second pressure sensors) 18b and 18c detect pressures at both ports of the hydraulic motor 3. The pressure sensors (third pressure sensors) 18d and 18e detect the operation pressure (pilot pressure) of the operation lever 7.

  As shown in FIG. 8A, the controller 17 includes a CPU 17a that performs various calculations, a storage device 17b such as a ROM or an HDD that stores programs for executing the calculations by the CPU 17a, and operations when the CPU 17a executes the programs. The RAM 17c, which is an area, and hardware including a communication interface (communication I / F) 17d, which is an interface for transmitting / receiving data to / from other devices, and software stored in the storage device 17b and executed by the CPU 17a Is done. Each function of the controller 17 is realized by the CPU 17a loading various programs stored in the storage device 17b to the RAM 17c and executing them.

  As shown in FIG. 8B, the controller 17 receives pressure sensors 18a, 18b, 18c, 18d, and 18e from the accumulator pressure Pac, both port pressures Pa and Pb of the hydraulic motor 3, and the operation lever 7, respectively. Side and lowering side pilot pressures Pu and Pd are inputted. The controller 17 hydraulically controls the hydraulic motor tilt calculation unit (first tilt calculation unit) 50 that calculates the tilt of the hydraulic motor 3 and the tilt of the hydraulic motor 3 calculated by the hydraulic motor tilt calculation unit 50. A hydraulic motor tilt output unit (first tilt output unit) 51 that outputs to the motor regulator 3a ′; a pump motor tilt calculation unit (second tilt calculation unit) 52 that calculates the tilt of the pump motor 14; A pump motor tilt output unit (second tilt output unit) 53 that outputs the tilt of the pump motor 14 calculated by the pump motor tilt calculation unit 52 to the pump motor regulator 14a ′.

  The hydraulic motor tilt calculation unit 50 and the pump motor tilt calculation unit 52 determine the tilt by calculation based on the pressure signals from the pressure sensors 18a to 18e so that the torque shown in FIGS. Then, the hydraulic motor tilt output unit 51 and the pump motor tilt output unit 53 are respectively controlled by tilt control signals (tilt commands) to the hydraulic motor regulator 3a ′ and the pump motor regulator 14a ′ so as to achieve the determined tilt. ) Is output.

  As described above, even with the hydraulic drive device according to the second embodiment adopting the configuration of the electric control regulator, the lifting and lowering work of the crane can be performed with high accuracy as in the first embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention, and all technical matters included in the technical idea described in the claims are included. The subject of the present invention. The above embodiment shows a preferable example, but those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification, These are included in the technical scope described in the appended claims.

1 Engine 2 Main pump (hydraulic pump)
3 Hydraulic motor 3a, 3a 'Regulator for hydraulic pump (first regulator)
4 Directional control valve 7 Operating lever (operating device)
9a Lowering line 9b Raising line 13 Hoisting drum (winch drum)
14 Pump motor (hydraulic pump motor)
14a, 14a 'Pump motor regulator (second regulator)
15 accumulator 17 controller 18a to 18e pressure sensor 31 direction switching valve 33 first sleeve 34 first spool 35 first piston 36 second piston 37 first servo piston 38 first link 39a first pressure chamber 39b second pressure chamber 39c second 3 pressure chamber 40 1st hydraulic chamber 140 2nd hydraulic chamber 142 2nd spring 143 2nd sleeve 144 2nd spool 145 3rd piston 146 4th piston 147 2nd servo piston 148 2nd link 149a 4th pressure chamber 149b 5th Pressure chamber

Claims (4)

An engine, a hydraulic pump driven by the engine, a hydraulic motor driven by pressure oil discharged from the hydraulic pump, a winch drum connected to a rotary shaft of the hydraulic motor, and a rotary shaft of the hydraulic motor The hydraulic pump motor connected to the hydraulic pump, the pressure oil discharged from the hydraulic pump motor is accumulated, the accumulator supplying the accumulated pressure oil to the hydraulic pump motor, and the pilot pressure corresponding to the operation amount is generated In a crane hydraulic drive apparatus comprising: an operating device; a first regulator that controls tilt of the hydraulic pump; and a second regulator that controls tilt of the hydraulic pump motor;
The crane hydraulic drive apparatus, wherein the pilot pressure is input to the first regulator and the second regulator through a pipe line. The crane hydraulic drive apparatus according to claim 1,
A crane hydraulic drive apparatus that controls the second regulator so that the torque of the hydraulic pump motor is constant regardless of the pressure of the accumulator. The hydraulic drive device for a crane according to claim 2,
The first regulator includes:
A first servo piston that is connected to the swash plate of the hydraulic motor and makes the tilt of the hydraulic motor variable, a first spool that controls the pressure in the first hydraulic chamber of the first servo piston, and the first servo A first sleeve connected to the piston by a first link and operating in the axial direction in synchronization with the first servo piston, a first spring for pressing the first spool in one axial direction, and the first spool A first piston for operating the second spool in the axial direction; a second piston for operating the first spool in the first axial direction; and for applying the pilot pressure to the second piston. A first pressure chamber, a second pressure chamber for applying a pressure on the high pressure side of both port pressures of the hydraulic motor to the first piston, and a pressure on the low pressure side of both port pressures of the hydraulic motor. A third pressure chamber for applying to the second piston, an input both ports pressure of the hydraulic motor, and a directional control valve for feeding selectively to said second pressure chamber the pressure of the high pressure side,
The second regulator is
A second servo piston connected to the swash plate of the hydraulic pump motor, wherein the tilt of the hydraulic pump motor is variable; a second spool for controlling the pressure in the second hydraulic chamber of the second servo piston; A second sleeve connected to the second servo piston by a second link and operating in the axial direction in synchronization with the second servo piston; a second spring for pressing the second spool toward one side in the axial direction; A third piston for operating the two spools on the other side in the axial direction, a fourth piston for operating the second spools on one side in the axial direction, and the pilot pressure acting on the fourth piston And a fourth pressure chamber for causing the pressure of the accumulator to act on the third piston. The hydraulic drive device for a crane according to claim 2,
A first pressure sensor for detecting the pressure of the accumulator; a second pressure sensor for detecting a pressure of a port of the hydraulic motor; a third pressure sensor for detecting a pilot pressure generated by the operating device; And a controller for controlling the first regulator and the second regulator,
The controller includes a first tilt calculation unit that calculates the tilt of the hydraulic pump based on a pressure signal from each pressure sensor, and a tilt command obtained by the first tilt calculation unit. A first tilt output unit that outputs to the second, a second tilt calculation unit that calculates the tilt of the hydraulic pump motor, and a tilt command obtained by the second tilt calculation unit is output to the second regulator. A crane hydraulic drive device comprising: a second tilt output unit.

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