JP2512892B2 - Crane drive system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a crane drive system which can be suitably applied to an overhead traveling crane or the like having a pair of winches.

[Prior Art] Conventionally, an overhead traveling crane generally uses an electric motor, but the electric traveling type crane is not suitable for moving a heavy object at a high speed. Therefore, for example, in a galvanizing factory or the like where high-speed transfer of a work from a plating tank to a cooling tank is required, adoption of a hydraulic crane that can easily achieve high torque is being considered.

[Problems to be Solved by the Invention] However, since the conventional hydraulic crane is generally an independent operation type, it is difficult to economically perform high-speed transportation of heavy objects as it is. There is.
That is, most winches mounted on trucks and the like are of hydraulic type, but in the conventional one, a single winch is controlled by a specific circuit. However, in order to enable a single winch to carry heavy objects at high speed, it is indispensable to increase the capacity of the hydraulic pump and the hydraulic motor, resulting in poor efficiency when handling a relatively lightweight work. To deal with such an inconvenience, for example, a pair of winches are arranged side by side, and both winches are used when handling a heavy object, and a single winch is used when handling a lightweight work. It is possible to do so. However,
If the winches arranged in parallel are of the independent operation type, there is a problem that it is difficult to control the speed when raising and lowering a common heavy object by using these winches.

The present invention aims to eliminate such inconvenience.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a pair of hydraulic motors for individually driving a pair of winches, and a pair of hydraulic pressures for discharging high-pressure hydraulic fluid. A pump, and an independent operation circuit for separately operating each of the hydraulic motors by hydraulic fluid discharged from at least one of these hydraulic pumps,
A tuning operation circuit that supplies the hydraulic fluid discharged from at least one of the hydraulic pumps to each of the hydraulic motors while controlling the hydraulic fluid to be equalized by a flow divider, and the tuning operation circuit and the isolated operation circuit. Circuit selection means for selective use and stepless adjustment of the amount of hydraulic fluid supplied to one hydraulic motor during use of the independent operation circuit, and operation supplied to both hydraulic motors during use of the synchronized operation circuit A first flow control valve for steplessly adjusting the amount of liquid, and a second flow control valve for steplessly adjusting the amount of hydraulic liquid supplied to the other hydraulic motor during use of the isolated operation circuit. And the circuit selecting means connects one isolated operation circuit to the inlet of one hydraulic motor in the first switching position and to the inlet of the tuning operation circuit in the second switching position. To the second switching position And the first flow path switching valve connecting the outlet of the tuning operation circuit to the inlet of one hydraulic motor and the other hydraulic motor are shut off from the tuning operation circuit in the first switching position and in the second switching position. A second flow path switching valve connected to the outlet of the tuning operation circuit and connecting the outlet of the other hydraulic motor to the outlet of the one hydraulic motor at the second switching position. And

[Operation] According to such a configuration, it is possible to operate the pair of winches independently or in synchronization, and it is possible to perform stepless speed change during each operation.

That is, during the isolated operation, the operating speeds of the winches can be adjusted steplessly by adjusting the first and second flow rate control valves.

On the other hand, during the synchronous operation, the hydraulic fluid discharged from the hydraulic pump is distributed and supplied to each of the hydraulic motors, but the distribution ratio is accurately defined by the flow divider in halves.
The hydraulic motors operate at the same speed. The operating speed can be continuously adjusted by a single flow control valve, that is, the first flow control valve.

In particular, since the present invention uses the flow divider, it exerts an action that cannot be obtained by a structure in which the inlets of the pair of hydraulic motors are simply communicated with each other by pressure conduits or the like to keep the pressure constant. That is, when a pressure conduit or the like is used, since the driving is performed by individual circuits, there is no guarantee that the winches will be driven evenly when an unbalanced load is applied to each motor. On the other hand, in the present invention, since the working fluid supplied through one of the single operation circuits is diverted, the basic drive source is common, and the working fluid surely bisected from the shunt is used in both hydraulic motors. Therefore, the synchronous drive can be effectively performed regardless of the uneven load.

In addition, since the present invention uses two flow path switching valves in adopting such a flow divider, the liquid supply / drainage circuit to the hydraulic motor can be effectively utilized. That is, when the tuning operation circuit having a flow divider is simply connected near the outlet of the hydraulic pump and the circuit selecting means is provided between the operation circuit and the isolated operation circuit, the hydraulic fluid after the diversion is supplied to both hydraulic motors. Furthermore, the circuit configuration of the supply / discharge system until the drainage from both hydraulic motors is returned to the tank is almost in parallel with the independent operation circuit, and twice the number of component parts is required, leading to an increase in size of the device. On the other hand, in the present invention, by using the two flow path switching valves, the hydraulic fluid that had directly flown into one of the hydraulic motors up to that time is once passed through the tuning operation circuit immediately before the inflow. The hydraulic fluid is caused to flow into the hydraulic motor so that the liquid after the hydraulic fluid is returned in the same drainage system, and when the hydraulic fluid flows out from the tuning operation circuit, the hydraulic fluid is caused to flow into the other hydraulic motor. The liquid that has flowed out is combined with the drainage system of the one hydraulic motor. Therefore, it can be configured simply by adding simple element parts near the inlet and outlet of the pair of hydraulic motors, and most of the other components can be covered by that of the independent operation circuit, effectively using existing equipment. In addition, the present invention can be easily applied to existing equipment.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an overhead traveling crane, in which 1 is a bridge frame that moves horizontally on the ceiling,
2A and 2B are rails supported by this bridge frame, 3A and 3B are crane carriages that can run along these rails 2A and 2B, and for winding the wires 4A and 4B on these crane carriages 3A and 3B. It is equipped with winches 5A and 5B. Each winch
5A and 5B are winch drums 6A and 6B and each winch drum
It comprises a hydraulic motor (hydraulic motor) 7A, 7B for driving 6A, 6B. Hooks 8A, 8B are provided at the lower ends of the wires 4A, 4B wound on the winch drums 6A, 6B. Is provided, and the lower end hook portion 9a of the T-shaped plate 9 hooked on these hooks 8A and 8B can lift the required work 10.

Fig. 2 shows a crane drive system for driving winches 5A and 5B of such a crane.
A and 11B are hydraulic pumps (hydraulic pumps), and 12A and 12B are the hydraulic pumps 11A and 11B and the hydraulic motors 7A and 7B.
It is a solenoid valve provided between and. One hydraulic pump 11A is configured such that _two pump bodies 11A ₁ and 11A ₂ are driven by a common motor 13A. The other hydraulic pump
11B is a common motor 13B for the _two pump bodies 11B ₁ and 11B ₂
It is configured to be driven by. The solenoid valves 12A and 12B are 4-port 3-position directional control valves.
When both solenoids SOLA, SOLB, SOLC, SOLD are not energized, they are held at the neutral position I, but when the first solenoids SOLA, SOLC are energized, they are switched to the forward rotation position II. When the 2 solenoids SOLB and SOLD are excited, it switches to the reverse rotation position III. And
The pressure port p of each solenoid valve 12A, 12B is connected to one pump main body 11 of the hydraulic pumps 11A, 11B via oil supply lines 15A, 15B.
The tank port t is opened to the tank 17 through the oil drain pipes 16A and 16B while being connected to A ₁ and 11B ₁ . Further, one inflow / outflow port c of each solenoid valve 12A, 12B is connected to one inflow / outflow port p1 of the corresponding hydraulic motor 7A, 7B via the first inflow / outflow conduit 18A, 18B, and the other The inflow / outflow port d is connected to the other inflow / outflow port p2 of the corresponding hydraulic motors 7A, 7B via the second inflow / outflow conduits 19A, 19B.

21 and 22 are relief valves, 23 and 24 are check valves, and 25
A and 25B cooperate with the check valve 24 and the second pump body 11
The hydraulic oil discharged from A ₂ and 11B ₂ is supplied to the oil supply lines 15A and 15B.
This is a solenoid valve for selecting whether to join the tank or return it to the tank 17. That is, the solenoid valves 25A and 25B are
When OLE and SOLF are not excited, the solenoids SOL are held in the open position I which opens the pipelines 26A and 26B.
When E and SOLF are excited, it switches to the breaking position II.

Reference numerals 31A and 31B are counter balance valves provided in the middle of one of the inflow / outflow conduits 18A and 18B, and 32A and 32B are brake valves provided between the inflow / outflow conduits 18A and 18B. The counter balance valves 31A and 31B are for preventing hunting at the time of lowering as described later, and the brake valves 32A and 32B are for absorbing surge pressure at the time of rapid operation.

Reference numerals 33A and 33B are first and second electromagnetic proportional flow rate control valves provided in the middle of one of the inflow / outflow conduits 18A and 18B. The flow rate control valves 33A and 33B are configured so that the set flow rate thereof changes steplessly according to the operation amount of the levers 34A and 34B for remote operation. The potentiometers 35A and 35B shown in FIG. 3 are rotated by the operating levers 34A and 34B, and the resistance change is detected by the power amplifiers 36A and 36B.
Is converted into an electric signal for driving the flow rate control valve to electromagnetically change the set flow rate of the electromagnetic proportional flow rate control valves 33A and 33B. Then, in this embodiment, a branch circuit is installed which is switched on according to the resistance positions of the potentiometers 35A and 35B, and the solenoid valves 12A and 1
2B, 25A, 25B solenoids SOLA, SOLB, SOLC, SOLD, SO
It is possible to excite LE, SOLF, etc.

37A and 37B are brake cylinders for braking the winch drums 6A and 6B. The brake cylinders 37A and 37B are single-acting hydraulic cylinders that operate in the direction in which the brake is applied by the urging force of the spring 38, and move in the brake release direction by supplying hydraulic oil from the inflow / outflow port q into the cylinders. It is like this.
The inflow / outflow port q of the brake cylinders 37A, 37B is selectively connected to the oil drain pipe 41 or the high pressure supply circuits 42A, 42B via the electromagnetic valves 39A, 39B. High voltage supply circuit
42A and 42B are the inflow and outflow conduits using the check valves 43 and 44 which make a pair.
The pressure oil can always be taken out from the high pressure side of 18A, 18B, 19A, 19B. And both the inflow and outflow lines 18
A and 18B are communicated with each other via a pipe line 46, a solenoid valve 45 and a pipe line 67, and the high pressure supply circuits 42A and 42B are connected to each other via a pipe line 48, a solenoid valve 47 and a pipe line 66. are doing. The solenoid valve 45 is held at the closed position I when the solenoid SOLM is not excited, and is switched to the communication position II when the solenoid SOLM is excited. The solenoid valve 47 is held at the closed position I when the solenoid SOLN is not excited, and is switched to the communication position II when the solenoid SOLN is excited.

51 is a shunt. The flow divider 51 includes two mechanically directly connected equal-capacity hydraulic pumps / motors 52 and 53, which are used to discharge the hydraulic oil discharged from a single first port e
It is designed so that it can be derived from the second port f, g which is divided into equal parts. The first port e is connected to the pump side portion 18Ap of the one inflow / outflow conduit 18A via the conduit 58, the solenoid valve 54, the conduit 55 and the solenoid valve 56. Also,
One of the second ports f is connected to the motor side portion 18Am of the inflow / outflow conduit 18A via the conduit 59 and the solenoid valve 56, and the other second port g is connected to the inflow / outflow conduit via the conduit 61. It communicates with 18B. Solenoid valve 54 is solenoid S
When the OLG is not excited, it is held at the closed position I, and when the solenoid SOLG is excited, it is switched to the communication position II. Further, the solenoid valve 56 is held at the shut-off position I that cuts off the communication between the port f and the inflow / outflow conduit 18A when the solenoid SOLH is not excited, and is switched to the communication position II when the solenoid SOLH is excited. It has become so.

Thus, in this embodiment, the isolated operation circuit A (B)
Is one of the inflow and outflow lines with the oil supply line 15A (15B), the solenoid valve 12A (12B), and the solenoid proportional flow control valve 33A (33B) interposed.
18A (18B), the other inflow / outflow conduit 19A (19B), and the oil drainage conduit 16A (16B). Also, the tuning operation circuit C
Is the flow divider 51 and the pump-side portion 1 of the one inflow / outflow line 18A.
Pipe line 5 for connecting 8 Ap to the first port e of the flow divider 51
Pipe line 5 for connecting 5, 58 and one second port f of the flow divider 51 to the motor side portion 18Am of the inflow / outflow line 18A.
9 and the other second port g of the flow divider 51 are connected to the inflow / outflow line 1
And a conduit 61 communicating with 8B. A circuit for selecting whether to perform the independent operation of the winches 5A and 5B with the tuning operation circuit C in the rest state or to perform the tuning operation of the winches 5A and 5B with the tuning operation circuit C in the use state. The selecting means D is composed of the solenoid valves 54 and 56.

Next, the operation of this embodiment will be described separately for single-action operation and synchronous operation.

I In the case of independent operation When stopped, each solenoid valve 12A, 12B, 25A, 25B, 39A, 39
B, 45, 47, 54 and 56 are held at the positions shown in FIG. 2, and the brake cylinders 37A and 37B are returned to the most retracted position by the spring 38.

From this state, for example, when the operation lever 34A is rotated counterclockwise in FIG. 3, the flow rate control valve 33A is opened corresponding to the amount of rotation operation, and the solenoid is operated.
The SOLA and the solenoid SOLJ are excited to switch the solenoid valve 12A to the forward rotation position II and the solenoid valve 39A to the position II. As a result, high-pressure hydraulic oil discharged from _one pump body 11A ₁ of the hydraulic pump 11A is supplied to one inflow / outflow port P1 of the hydraulic motor 7A through the oil supply line 15A and the one inflow / outflow line 18A. 7A operates in winch hoisting direction. Then, the waste oil discharged from the hydraulic motor 7A is returned to the tank 17 through the other inflow / outflow conduit 19A and the oil discharge conduit 16A. Therefore, since the flow rate of the hydraulic fluid flowing through the inflow / outflow conduit 15A is continuously controlled by the flow rate control valve 33A, the hydraulic motor 7A is operated by the operation lever 34A.
It operates at a speed corresponding to the operation amount of. As a result, the winch drum 6A rotates in the normal direction, and the wire 4A is wound up. At this time, the hydraulic oil in the high pressure supply circuit 42A is transferred to the brake cylinder 3
Brake cylinder 37A since it is introduced to port q of 7A
Is operating in the forward direction, and the brake of the winch drum 6A is released. When the operation lever 34A is further rotated counterclockwise to increase the set flow rate of the flow rate control valve 33A, energization of the solenoid SOLE is added in the middle of the operation. Then, the solenoid valve 25A moves from position I to position I.
The second pump body 1 that was switched to I and was discarded in the tank 17
The hydraulic oil from 1A ₂ is additionally supplied to the oil supply line 15A.
In other words, while the flow rate is low, only _one pump body 11A ₁ is used, and when the flow rate is relatively high, both pump bodies 11A ₁ ,
It is designed to use 11A ₂ and can save energy. On the other hand, when the operation lever 34A is operated in the clockwise direction from the neutral position shown in FIG. 3, the flow control valve 33A is opened corresponding to the amount of the rotational operation, and the solenoid SOLB and the solenoid SOLJ are opened. Excited, solenoid valve 12
A is switched to reverse rotation position III, and solenoid valve 39A is switched to position II.
As a result, high-pressure hydraulic oil discharged from _one pump body 11A ₁ of the hydraulic pump 11A passes through the oil supply line 15A and the other inflow / outflow line 19A, and the other inflow / outflow port P of the hydraulic motor 7A.
2, the hydraulic motor 7A operates in the winch lowering direction. Then, the waste oil discharged from the hydraulic motor 7A is returned to the tank 17 through one inflow / outflow conduit 18A and one oil discharge conduit 16A. Then, since the flow rate of the hydraulic oil flowing through the inflow / outflow conduit 18A is continuously controlled by the flow rate control valve 33A, the hydraulic motor 7A operates at a speed corresponding to the operation amount of the operation lever 34A. To do. As a result, the winch drum 6A is reversed and the wire 4A is wound down. Also at this time, the hydraulic oil of the high pressure supply circuit 42A is introduced into the port q of the brake cylinder 37A, so that the brake cylinder 37A is operating in the forward direction and the winch drum 6
The brake of A is released. When the operating lever 34A is further rotated clockwise to increase the set flow rate of the flow rate control valve 33A, energization of the solenoid SOLE is added in the middle of the operation. Then, the solenoid valve 25A is switched from the position I to the position II, and the hydraulic oil from the second pump body 11A ₂ which has been discarded in the tank 17 is additionally supplied to the oil supply pipeline 15A. When the flow rate is controlled by the flow rate control valve 33A to lower the flow rate, unnecessary fluid is returned to the tank 17 through the relief valve 22. Flow control valve 33A when unwinding
Since the hunting phenomenon is likely to be caused by only the control, the counterbalance valve 31A is used to reduce the differential pressure of the flow control valve 33A. Further, the hydraulic motor 7A acts as a pump at the time of winding, and the load pressure becomes too large depending on the magnitude of the load, so the set pressure of the relief valve 22 is set to a low value (counter balance valve 31
The pressure required to push A open) is set to protect the equipment. Therefore, the oil that has passed through the flow control valve 33A pushes open the counter balance valve 31A,
It passes through the solenoid valve 12A and is returned to the tank 17. Operating lever 3
If the 4A is rapidly operated from the zero position to the maximum and returned to the zero position, a sudden surge pressure will be generated due to the stop of the winch 5A. Be absorbed.

Although the operation of the isolated operation circuit A related to the one winch 5A has been described above, the same applies to the isolated operation circuit B related to the other winch 5B, and the other hydraulic motor 7B corresponding to the operation of the operation lever 34B. The operation of can be controlled.

II Synchronous operation Low speed synchronous operation (using pump 11A only) As shown in Fig. 1, when the work 10 is moved using the pair of winches 5A and 5B, that is, the hooks 8A and 8B.
When the T-shaped plate 9 is attached to and the work 10 is lifted, both winches 5A and 5B must move in synchronization.
Therefore, at this time, the first electromagnetic proportional control valve 33A is activated and the second electromagnetic proportional control valve 33B is turned on by the power amplifier 3.
Fully closed by switching 6B to OFF. Then, the solenoids SOLA, SOLG, SOLH, SOLJ, SOLK, SOLN are excited to switch the solenoid valves 12A, 39A, 39B, 47, 54, 56 to the position II. As a result, the hydraulic oil discharged from the hydraulic pump 11A is shunted through the oil supply conduit 15A, the pump side portion 18Ap of the one inflow / outflow conduit 18A, the electromagnetic valve 56, the conduit 55, the electromagnetic valve 54 and the conduit 58. It is introduced into the first port e of 51. And
The hydraulic oil bisected by the flow divider 51 is guided to the hydraulic motors 7A and 7B, respectively, and drives the motors 7A and 7B to return to the tank 17. That is, one second port f of the shunt 51
The hydraulic oil derived from is guided to the inflow / outflow port p1 of the hydraulic motor 7A through the conduit 59, the solenoid valve 56, and the motor side portion 18Am of the inflow / outflow conduit 18A, and operates this hydraulic motor 7A. Then, the other inflow / outflow port p2 of this hydraulic motor 7A
Waste oil discharged from
It is returned to the tank 17 through 2A and the oil drain pipe 16A. Further, the hydraulic oil derived from the other second port g of the flow divider 51 is guided to one inflow / outflow port p1 of the hydraulic motor 7B through the conduit 61 and the inflow / outflow conduit 18B to operate the hydraulic motor 7B. Let Then, the waste oil discharged from the other inflow / outflow port p2 of the hydraulic motor 7B is supplied to the conduit 62 and the solenoid valve.
It is guided to the inflow / outflow line 19A through the 54 and the line 63, and the inflow / outflow line 19A, the solenoid valve 12A and the oil drain line 16A.
Is returned to the tank 17 through. In this case, the high voltage supply circuit
The hydraulic oil of 42A is supplied to the port q of one brake cylinder 37A through the pipe 65 and the solenoid valve 39A, and the hydraulic oil of the other brake cylinder 37B passes through the pipe 48, the solenoid valve 47, the pipe 66 and the solenoid valve 39B. Since the brake cylinders 39A and 39B are supplied to the port q, both brake cylinders 39A and 39B are held at the forward position, and the brakes on the winch drums 6A and 6B are released. Therefore, the both hydraulic motors 7A rotate the winch drums 6A and 6B in the forward direction at the same speed.
A and 4B are rolled up to lift the work 10. When the operation lever 34A is further rotated counterclockwise to increase the set flow rate of the flow rate control valve 33A, energization of the solenoid SOLE is added in the middle of the operation. Then,
The solenoid valve 25 is switched from the position I to the position II, and the hydraulic oil from the second pump body 11A ₂ which has been discarded in the tank 17 is additionally supplied to the oil supply line 15A.

In addition, reverse the hydraulic motors 7A and 7B to winches 5A and 5B.
When winding down, the solenoid valve 12A may be switched to the reverse rotation position III.

High-speed synchronized operation (using both hydraulic pumps 11A and 11B) When performing synchronized operation using the hydraulic pumps 11A and 11B at the same time, the solenoid SOL can be operated by operating the operating lever 34A.
When energizing A, the solenoid SOLC is energized at the same time, and when energizing the solenoid SOLB, the solenoid SOLD is energized at the same time. For example, when performing synchronized operation at the highest speed in the winding direction, the solenoid SOLA,
SOLC, SOLE, SOLF, SOLG, SOLH, SOLJ, SOLK, SOLM, SO
Exciting LN, solenoid valves 12A, 12B, 25A, 25B, 39A, 39B,
Switch 45, 47, 54, 56 to position II. As a result, the hydraulic oil discharged from the hydraulic pump 11A is guided to the one inflow / outflow conduit 18A through the oil supply conduit 15A and the solenoid valve 12A, and the hydraulic oil discharged from the other hydraulic pump 12B is supplied to the oil supply conduit. 15B, solenoid valve 12B, pipeline 67, solenoid valve 45 and pipeline
It merges with the inflow / outflow conduit 18A through 46. Then, the combined hydraulic oil introduced into the pump side portion 18Ap of the inflow / outflow conduit 18A passes through the flow rate control valve 33A, is guided from the solenoid valve 56 to the pipeline 55, and passes through the solenoid valve 54 and the pipeline 58. It is introduced into the first port e of the flow divider 51. And this shunt
The hydraulic oil bisected in 51 is guided to the hydraulic motors 7A and 7B, drives these motors 7A and 7B, and returns to the tank 17, as in the above-described low-speed synchronizing operation. Therefore, the both hydraulic motors 7A rotate the winch drums 6A and 6B in the forward direction at the same speed, and the wires 4A and 4B are wound up to lift the work 10. In the above, the case of hoisting was described, but in the case of hoisting, the solenoid
Instead of SOLA and SOLC, the solenoids SOLB and SOLD may be excited to switch the solenoid valves 12A and 12B to the reverse rotation position III.

In this case, the pump flow rate of the pump 11B merges with the circuit of the pump 11A at the time of ascent and descent, and the speed range can be widely used. Also at this time, the speed of both winches 5A and 5B can be controlled by changing the set flow rate of the first flow control valve 33A only by operating one lever 34A.

With such a structure, when handling a relatively lightweight work, either one of the winches 5A or 5B is actuated independently, and when the heavy work 10 as described above is lifted or lowered. Since the pair of winches 5A and 5B can be operated synchronously, it is possible to achieve both high efficiency in the transportation of lightweight objects and high-speed transportation of workpieces. Moreover, it is of course possible to independently control the operating speed of each winch 5A, 5B by independent operation of each flow rate control valve 33A, 33B during independent operation, and even during synchronous operation, a single operation is possible. By operating the flow control valve 33A, the operating speed of both winches 5A and 5B can be controlled. That is, when the tuning operation circuit is selected, the hydraulic oil bisected by the action of the shunt 51 is evenly supplied to both winches 5A and 5B, so these winches 5A and 5B should be accurately tuned. It is possible to operate, and since its synchronizing speed can be adjusted by operating a single flow control valve 33A, it feels as if a single winch is operating. Therefore, the operation can be simplified.

In addition, although the above-mentioned embodiment demonstrated the case where this invention was applied to the overhead traveling type crane, it is not limited to this type of crane.

Further, in the above-mentioned embodiment, the case where the first hydraulic pump and the second pump are of a multiple type having a pair of pump main bodies respectively has been described, but the present invention is not limited to this. It is not limited to such a thing. However, if each hydraulic pump is of a multiple type as described above, the number of pump bodies used can be appropriately changed according to the required flow rate. Therefore, the amount of the hydraulic fluid returned to the tank via the relief valve can be effectively reduced, and the energy loss can be reduced and the economical operation can be performed. That is, in the case of the above embodiment, only the pump body 11A ₁ is used and the pump body 11A ₁
And 11A ₂ , using pump body 11A ₁ , 11A ₂ , 11B ₁ ,
It is possible to switch to four modes of using the pump bodies 11A ₁ , 11A ₂ , 11B ₁ , 11B ₂ .

Further, in the above-described embodiment, the case where each hydraulic motor is separately operated by the hydraulic fluid from each corresponding hydraulic pump in the independent operation has been described, but the present invention is not necessarily limited to such. For example, one hydraulic motor may be allowed to operate at high speed using not only the hydraulic fluid from one hydraulic pump but also the hydraulic fluid from the other hydraulic pump.

Further, it goes without saying that the flow control valve is not limited to the electromagnetic type, but if the electromagnetic type is adopted, remote operation becomes easy.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to efficiently handle a relatively light work piece to a relatively heavy work piece at a high speed, and moreover, it is mainly a large weight piece. It is possible to provide a crane drive system capable of accurately performing a winch synchronized operation required for handling a work by a simple operation.

In particular, the crane drive system of the present invention can reliably drive the pair of winches in synchronization with each other even if the loads applied to the pair of hydraulic motors are biased.
It has an excellent effect of guaranteeing safety and reliability, and can be configured by simply adding simple element parts to existing equipment, so that existing equipment can be effectively used and the present invention can be easily applied to existing equipment. Will be things.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is an external view schematically showing a crane, FIG. 2 is a circuit explanatory view, and FIG. 3 is an explanatory view showing an operating portion of a flow control valve. 5A, 5B …… Winches 7A, 7B …… Hydraulic motors (hydraulic motors) 11A, 11B …… Hydraulic pumps (hydraulic pumps) 33A …… First flow control valve 33B …… Second flow control valve 51… … Shunts A, B …… Single operation circuit C …… Synchronous operation circuit D …… Circuit selection means 54 …… Second flow path switching valve (solenoid valve) 56 …… First flow path switching valve (solenoid valve) )

Claims (1)

(57) [Claims] 1. A pair of hydraulic motors for individually driving a pair of winches, a pair of hydraulic pumps for discharging high-pressure hydraulic fluid, and a hydraulic fluid discharged from at least one of these hydraulic pumps. An independent operation circuit for individually operating each of the hydraulic motors and a hydraulic fluid discharged from at least one of the hydraulic pumps are supplied to both hydraulic motors while being controlled to be equalized by a flow divider. Tuning operation circuit, a circuit selecting means for selectively using the tuning operation circuit and the isolated operation circuit, and steplessly changing the amount of hydraulic fluid supplied to one hydraulic motor during use of the isolated operation circuit. A first flow control valve that adjusts and continuously adjusts the amount of hydraulic fluid supplied to both hydraulic motors when using the synchronous operation circuit, and is supplied to the other hydraulic motor while using the independent operation circuit. Amount of hydraulic fluid And a second flow rate control valve for stepless adjustment, wherein the circuit selection means is provided on one of the independent operation circuits in the vicinity of the inlet of one hydraulic motor at a first switching position at the hydraulic motor. First flow path switching valve that is connected to the inlet of the hydraulic drive motor and is connected to the inlet of the tuning operation circuit at the second switching position and the outlet of the tuning operation circuit is connected to the inlet of one hydraulic motor at the second switching position. And the vicinity of the inlet of the other hydraulic motor is cut off from the tuning operation circuit at the first switching position, connected to the outlet of the tuning operation circuit at the second switching position, and the other hydraulic pressure is applied at the second switching position. A crane drive system comprising a second flow path switching valve connecting an outlet of the motor to an outlet of the one hydraulic motor.