JP2000053383A - Hydraulic drum driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To vary set torque of a hydraulic drum driving device according to uses. SOLUTION: When a winch changeover switch SW 1 is operated to the side of a 'leaving winch', a solenoid valve 8 is switched to a B switching position and hydraulic fluid discharged from a hydraulic pump 4 is relieved by relief pressure Pa by a relief valve 12. When the switch SW 1 is operated to the side of a 'hydraulic tag line', the solenoid valve 8 is switched to an A switching position and hydraulic fluid discharged from the hydraulic pump 4 is relieved by relief pressure Pb (Pa>Pb) by a relief valve 10. By operating winding/lowering operation switch SW 2 or a hydraulic tag line operation switch SW 3, a winch 20 is operated. At this time, upper limit torque of a hydraulic motor 22 is changed corresponding to relief pressure Pa or Pb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drum driving device for driving a drum for winding or unwinding a rope or wire by a hydraulic motor, and more particularly to a different upper limit torque corresponding to a plurality of different applications. The present invention relates to a hydraulic drum drive device which can be set.

[0002]

2. Description of the Related Art It is known that a hydraulic tag line is used to prevent a suspended load of a crane (such as a clamshell bucket or a lifting magnet) from swaying (for example, Japanese Utility Model Laid-Open No. 59-123076). This is a device that attenuates swing of a suspended load early when carrying out cargo handling work with a crane or the like. That is, apart from a main winding winch for lifting and lowering a main wire for suspending a suspended load and an up / down winch for driving the boom up and down, a hydraulic auxiliary winch is installed near a boom mounting portion of the crane body. You. Then, the tag line rope having one end connected to the suspended load side is wound on the winch drum, and the swing of the suspended load is suppressed by winding or unwinding the tag line rope on the drum according to the swing of the suspended load.

A description will be given of a hydraulic motor for preventing the suspended load of the crane described above. The hydraulic motor is supplied with a pressure from a hydraulic source so that a torque is always generated in a direction for driving the drum to the winding side. ing. Therefore, when the suspended load swings in the direction approaching the crane and the tag line rope slackens, the hydraulic motor drives the drum to the winding side to take up the slack. On the other hand, when the suspended load swings away from the crane and the tension of the tag line rope increases, the torque of the hydraulic motor loses the tension of the tag line rope, and the drum rotates to the lowering side. At this time, the hydraulic motor acts as a pump, and discharges (backflows) the working oil sucked from the discharge port of the hydraulic motor to the suction port. That is, the swing of the suspended load is suppressed by the amount of work required for the hydraulic motor to function as a pump.

By the way, a relief valve is connected in the middle of the pipeline connecting the hydraulic source and the inlet port of the hydraulic motor. When an overload is applied to the hydraulic motor, the hydraulic oil supplied from the hydraulic source is It is released from the relief valve together with the hydraulic oil discharged from the motor suction side. Therefore, the devices such as the hydraulic circuit and the hydraulic motor are not damaged by an overload.

[0005] The relief pressure of the above-described relief valve will be described. If the torque generated by the hydraulic motor is too high, the drum rotates in the hoisting direction when there is no suspended load, and the tag line rope lifts up a hanging tool such as a clamshell bucket, thereby reducing workability. Therefore, the relief pressure of the relief valve is set such that the drum rotates to the lowering side even when the tension of about its own weight of the hanging tool such as the clamshell bucket acts on the tag line rope.

As described above, the steady rest is performed using the hydraulic auxiliary winch different from the main winding winch and the undulating winch, and the hydraulic tag line is constituted by the tag line rope and the winch on which the tag line rope is wound. Is done.

By the way, a method of using a hydraulic auxiliary winch provided separately from the main winding winch and the undulating winch for the leaving operation described below is known.

[0008] Leaving work means that when assembling a crane at a work site, a main wire wound around a main winch is pulled out to the end of a boom, and the main wire is hung on sheaves provided on both the end of the boom and hooks or other hanging tools. It refers to turning work. Hereinafter, in this specification, the sheave provided at the end of the boom is referred to as “point sheave”, and the sheave provided on the hanger is referred to as “hanger sheave”.

Conventionally, the leaving operation has been performed manually, but at this time, a large number of workers are required. This is because the main wire is somewhat thick and heavy, and the length of the boom may reach, for example, 60 to 70 m. In other words, pulling out the heavy and difficult-to-manage main wire to the end of the boom is a difficult task,
Thereafter, in order to wrap a thick wire rope having a large bending rigidity around the point sheave and the hanger sheave, it is necessary to apply a certain amount of tension to the main wire. Unless this tension is considerably increased, it is impossible to wrap around the sheaves described above, and therefore, a large number of workers are required.

In order to solve this problem, a method of installing a leaching winch (hereinafter referred to as "leaving winch" in the present specification) near the boom mounting portion of the crane body as described below is also available. Are known.

A reeving winch around which a wire for leaving work (hereinafter referred to as "leaving wire" in the present specification), which is thinner than the main wire and easy to handle, is wound near the boom mounting portion of the crane body. Will be installed. At the time of the leaving operation, the operator pulls out the leaving wire from the leeving winch along the lower part of the boom, and wires the point sheave and the hanger sheave in a direction opposite to the direction in which the main wire is wound. Further, the leaving wire is pulled out along the upper part of the boom, and the tip of the leaving wire is connected to the tip of the main wire wound on the main winch.

Thereafter, the main wire is driven by the main winding winch → point sheave → suspension sheave →
, And the wiring of the main wire, that is, the leaving operation is completed. By using the leeving winch in this way, the leaving operation can be performed relatively easily without much human labor.

[0013]

However, in a crane device capable of performing a leaving operation with a leeving winch, for example, it is necessary to separately install a winch for a hydraulic tag line and a leeving winch for a leaving operation. The crane manufacturing cost has increased, and it has been difficult to secure a space for installing a plurality of winches.

This is because, as described above, the hoisting torque of the winch for the hydraulic tag line is set to a relatively low value, and the hoisting torque is insufficient for use in the leaving operation.

[0015] It is an object of the present invention to provide a hydraulic drum drive that can be used for a plurality of purposes by making a set upper limit torque of one hydraulic drum drive variable according to its use.

[0016]

Means for Solving the Problems (1) The present invention will be described with reference to FIG. 1 showing an embodiment. The invention according to claim 1 is a hydraulic motor that drives a drum 26 that draws in and pulls out a rope. 22; operation mode switching means SW1 for switching the operation mode of the drum 26 so as to correspond to a plurality of different uses; and operation mode switching means SW1.
The above-mentioned object is achieved by having the upper limit torque switching means 10, 12 and 8 for switching the upper limit torque of the hydraulic motor 22 according to the switching state. (2) Explaining in connection with FIG. 6 showing one embodiment, the invention according to claim 2 further includes a counterbalance valve 62 connected to the hydraulic motor 22 and includes a plurality of different usage purposes. One use is as an auxiliary winch for cargo handling.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used for easy understanding of the present invention. However, the present invention is not limited to this.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment A first embodiment of the present invention shows an example in which a hydraulic drum driving device is used for both a hydraulic tag line and a leaving winch. In FIG. 1 schematically showing a hydraulic drive circuit of the drum, a winch 20 can be used also as a winch for a leaving winch and a winch for a hydraulic tag line. The hydraulic pump 4 for driving the hydraulic motor 22 and the hydraulic pump 6 for driving the brake 24 are driven by the prime mover 2.

The winch 20 includes a hydraulic motor 22, a drum 26 driven to rotate by the hydraulic motor, and a brake 24 for braking the hydraulic motor 22. A solenoid valve (electromagnetic control valve) 14 is interposed in a pipeline connecting the hydraulic pump 4 and the hydraulic motor 22, and the flow direction of hydraulic oil guided from the hydraulic pump 4 to the hydraulic motor 22 is determined by the switching position of the solenoid valve 14. Can be switched according to.

A solenoid valve (an electromagnetic on-off valve) is provided in the middle of a pipe connecting the hydraulic pump 4 and the solenoid valve 14.
The relief valve 10 of the relief pressure Pb is connected via 8. A relief valve 12 having a relief pressure Pa is connected in the middle of the pipe in parallel with the relief valve 10. Here, the relief pressures Pa and Pb are upper limit pressures corresponding to the upper limit torque of the hydraulic motor 22 set when the winch 20 is used as a leaving winch or a hydraulic tag line. This is the upper limit pressure for the line. The relief pressure Pa is set higher than the relief pressure Pb. This is because a larger hoisting torque is required when the winch 20 is used as a leaving winch.

A solenoid valve (electromagnetic switching valve) 16 is interposed in a pipe connecting the hydraulic pump 6 and the brake 24, and the operation / non-operation of the brake 24 is controlled by the solenoid valve 1.
6 is switched according to the switching position. A relief valve 7 is connected in the middle of a pipe connecting the hydraulic pump 6 and the solenoid valve 16. The relief valve 7 is for relieving excess pressure of the hydraulic oil discharged from the hydraulic pump 6.

The hydraulic oil discharged from the three relief valves 7, 10 and 12 described above is all returned to the oil tank 1.

The switches SW1 to SW3 for switching the switching positions of the solenoid valves 8, 14 and 16 will be described with reference to FIGS. FIG.
How the solenoid valves 8, 14 and 16 are switched to which switching position in accordance with the switching state of the switches SW1 to SW3, and as a result, how the relief pressure is switched and the operation of the hydraulic motor 22 and the brake 24 are switched. It is a summary of what is done. The winch switch SW1 connected to the power supply 30 via the fuse 28
This is a switch for switching the mode of the winch 20 to a leaving winch or a hydraulic tag line. When the winch change switch SW1 is switched to the "leaving winch" side as shown in FIG. 1, the solenoid 8S is energized,
Solenoid valve 8 is in switching position B (non-communication state)
Switch to As a result, the upper limit torque of the hydraulic motor 22 (the upper limit torque for the reefing winch) becomes the relief pressure P
a.

The hoisting / unwinding operation switch SW2 is a switch for switching the hoisting / unwinding operation when the winch 20 is used as a leaving winch. When the hoisting / lowering operation switch SW2 is switched to the "winding" side while the winch changeover switch SW1 is switched to the "leaving winch" side, the solenoids 14S1 and 16S are energized, and the solenoid valve 14 becomes a C solenoid valve. Reference numeral 16 switches to the B switching position. As a result, the brake 24 is released, and the hydraulic oil discharged from the hydraulic pump 4 flows into the port 22a of the hydraulic motor 22, and the drum 26 rotates upward. Hydraulic motor 22
The hydraulic oil discharged from the port 22b of the oil tank 1
(Refer to (a) of FIG. 2).

On the other hand, when the hoist / lower operation switch SW2 is switched to the "lower side" while the winch changeover switch SW1 is switched to the "leaving winch" side, the solenoid 14S2 and the solenoid 16S are energized, and the solenoid valve 14 is turned on. And 16 each switch to the B switching position. As a result, the brake 24 is released and the hydraulic oil discharged from the hydraulic pump 4 flows into the port 22b of the hydraulic motor 22, and the drum 26 rotates to the lower side. The hydraulic oil discharged from the port 22a of the hydraulic motor 22 recirculates to the oil tank 1 (state (b) shown in FIG. 2).

The above-mentioned hoisting / lowering operation switch SW2 is a momentary switch. When the operator releases his / her hand from the hoisting / lowering operation switch SW2, this switch returns to the neutral position. When the hoisting / lowering operation switch SW2 is in the neutral position, the solenoids 14S1, 14S2 and 16
Since S is not energized, the solenoid valve 14 and the solenoid valve 16 are each switched to the A switching position. In this state, no hydraulic pressure acts on the hydraulic motor 22 and the brake 24, so that the driving force of the hydraulic motor 22 is lost, and the brake 24 acts to stop the drum 26 (state (c) shown in FIG. 2).

The hydraulic tag line operation switch SW3 is an operation switch for switching between steadying operation and stop when the winch 20 is used for a hydraulic tag line. Less than,
The operation of the winch 20 when the winch changeover switch SW1 is switched to the “hydraulic tag line” side and the hydraulic tag line operation switch SW3 is operated will be described.

When the winch changeover switch SW1 is switched to the "hydraulic tag line" side, the solenoid 8S
Is turned off, and the solenoid valve 8 switches to the A switching position. In this state, the relief valve 1 is located in the middle of the line connecting the hydraulic pump 4 and the solenoid valve 14.
2 (relief pressure Pa) and the relief valve 10 (relief pressure Pb) are connected in parallel. However, since the relief pressure Pb is set lower than the relief pressure Pa, when the internal pressure of the pipeline connecting the hydraulic pump 4 and the solenoid valve 14 exceeds Pb, the relief is performed. As a result, the upper limit torque of the hydraulic motor 22 becomes the relief pressure Pb
Is defined by If the hydraulic tag line operation switch SW3 is switched to "ON" while the winch change switch SW1 is switched to the "hydraulic tag line" side, the solenoid 1
4S1 and 16S are energized, and the solenoid valve 14 is switched to the switching position C and the solenoid valve 16 is switched to the switching position B. As a result, the brake 24 is released and the hydraulic motor 22 rotates upward (the state (d) shown in FIG. 2).

When the tag line operation switch SW3 is switched to "OFF" while the winch change switch SW1 is switched to the "hydraulic tag line" side, the solenoid 16S
While the power supply to the solenoid 14S1 is maintained, power is not supplied to both the solenoid 14S1 and the solenoid 14S2. As a result, the solenoid valve 16 is maintained at the B switching position, the solenoid valve 14 is switched to the A switching position (open center), the brake 24 is released, and the hydraulic motor 22 becomes free ((e in FIG. 2). ) State). That is, the drum 26 becomes freely rotatable.

When the leaving operation is performed using the winch 20 (FIG. 1) described above, FIG.
The leaving operation is performed in the order of (b) → FIG. 4 (a) → FIG. 4 (b). Also, here, the case of using a hook as a hanging tool will be described as an example to explain the leaving operation procedure.

As shown in FIGS. 3 and 4, the winch 20 around which the leaving wire 44 is wound is fixed near the tip of the main frame 60. In the state at the start of the leaving operation shown in FIG. 3A, the tip of the main wire 42 wound around the main winding winch 40 is pulled out near the attachment portion (root portion) of the boom 58. The leaving wire 44 wound around the winch 20 is connected to the boom 5.
8 are drawn out below.

The operator wires the leaving wire 44 to the hook sheave 48, the point sheave 50 and the guide sheave 52 of the hook 56 in a direction opposite to the direction in which the main wire 42 is wound around, and pulls out the wire along the upper surface of the boom 58. The leading ends of the leaving wire 44 and the main wire 42 are connected to each other using a flexible rope joint 46.

The operator switches the winch changeover switch SW1 to the "leaving winch" side, and switches the hoisting / lowering operation switch SW2 to the "winding" side (to the state shown in FIG. 2A). Thereby, the relief pressure becomes Pa
In the state set to (> Pb), the winch 20 operates in the winding direction, the slack of the main wire 42 and the leaving wire 44 is removed, and the state shown in FIG. 3B is obtained.
At this time, the main winch 40 is braked, and when the tension of the main wire 42 and the leaving wire 44 reaches a predetermined value, the relief valve Pa is activated and the winch 20 is stopped.

In the state described above, the operator operates a lever (not shown) so that the main wind winch operates to the lower side, whereby the winch 20 starts operating in the winding direction again.
As a result, the connecting portion (rope joint 46) between the main wire 42 and the leaving wire 44 advances in the direction opposite to the wiring direction of the leaving wire 44. And
When the rope joint 46 reaches below the tip of the boom 58, the operator stops the main wind winch 40 and then releases the hoisting / lowering operation switch SW2 (the state shown in FIG. 2C). To). This allows winch 2
0 stops, and the main wire 42 and the leaving wire 44 are in the state shown in FIG.

After completing the above operation, the operator connects the distal end of the main wire 42 from which the rope joint 46 has been removed to the rope socket 54 which is swingably fixed near the boom distal end, and completes the leaving operation.

Next, an example in which the hydraulic drum driving device is used as a hydraulic tag line will be described with reference to FIG. 5, which shows a state in which a clamshell bucket 56A is mounted as a hanging tool on a crane. The clamshell bucket 56 </ b> A suspended by the main wire 42 moves up and down by the hoisting / lowering drive of the main winch 40. The tag line 44A wound around the winch 20 is connected to the clamshell bucket 56A via the guide sheave 58a.

When the winch 20 is used for the hydraulic tag line, the operator switches the winch changeover switch SW1 to the "hydraulic tag line" side and switches the hydraulic tag line operation switch SW3 to the "ON" side ((d in FIG. 2). ) State). Thereby, the upper limit torque of the winch 20 is defined by the relief pressure Pb. This relief pressure Pb is lower than the relief pressure Pa set when the winch 20 is used as a leaving winch. More specifically, when the hydraulic tag line operation switch SW3 is switched to the "ON" side in the state shown in FIG. 5, even if the clamshell bucket 56A is empty, the arrow B
Is not greatly pulled in the direction of. Similarly, when the main winding winch 40 is driven in the lowering direction to lower the clamshell bucket 56, the winch 20 becomes the tag line 44A.
It starts to move in the lower direction by losing the tension of. On the other hand, when the clamshell bucket 56A swings in the direction of arrow B and the tag line 44A starts to loosen, the winch 20 rotates in the winding direction to keep the tension of the tag line 44A constant. When the clamshell bucket 56A swings in the direction of arrow A and the tension on the tag line 44A increases, the winch 20 loses the tension on the tag line 44A and exits the tag line 44A.
At this time, since a tension corresponding to the relief pressure Pb is acting on the tag line 44A, the clamshell bucket 5
6A can be attenuated quickly.

As described above, according to the hydraulic drum drive of the present embodiment, one winch can be used for different purposes, which is advantageous in terms of installation space and crane manufacturing cost. is there. In addition, winch 2
By using 0 as a leaving winch, it is possible to perform a leaving operation with a small number of workers. At this time, only by operating the winch changeover switch SW1 and the hoisting / lowering operation switch SW2, the upper limit torque suitable for using the winch 20 as a leaving winch is automatically set.

Similarly, the winch changeover switch SW1
Is switched to the "hydraulic tag line" side and the winch 20 can be used for the hydraulic tag line simply by switching the hydraulic tag line operation switch SW3 to "ON", so that the operability is excellent. At this time, since the upper limit torque of the motor 22 for driving the winch 20 is automatically set to an upper limit torque suitable for use as a hydraulic tag line device, work for adjusting the upper limit torque and confirming the set value is not necessary. It is unnecessary and has excellent workability. Further, it is possible to prevent the upper limit torque that does not suit the purpose of use from being erroneously set, thereby preventing a device failure or accident from occurring.

Further, in the hydraulic drive circuit shown in FIG. 1, the "leaving winch" of the winch changeover switch SW1 is set.
Protects the hydraulic drum drive even if the wiring connecting the terminal on the side and the solenoid 8S is broken or the solenoid 8S breaks down and the solenoid valve 8 does not switch from the switching position A to the switching position B. can do. That is, since the relief valves 10 and 12 are connected in parallel, when the solenoid valve 8 stops operating in the failure mode described above, a relatively low relief pressure Pb is set in the hydraulic drive circuit, and the device is overloaded. Can be prevented from acting and causing a failure.

In the above description of the embodiment, an example in which the hydraulic drum driving device is used for both the leaving operation and the hydraulic tag line has been described, but it is also possible to use it for other purposes. For example, one application may be used for a leaving operation and another application may be used with the main winch 40 to provide an auxiliary winch for cargo handling. Hereinafter, this example will be described with reference to FIGS. FIG. 6 shows a modification of the hydraulic drive circuit shown in FIG. 1 so that the hydraulic drive circuit can be used for both the leaving operation and the auxiliary winch. The same components as those in FIG. 1 are denoted by the same reference numerals. The description thereof will be omitted, and the description will focus on the differences from FIG.

In the hydraulic drive circuit shown in FIG. 6, the winch 20 shown in FIG.
A, the two-port solenoid valve 8 in FIG. 1 is changed to a three-port solenoid valve 8A, and the hydraulic tag line operation switch SW3 in FIG. 1 is omitted. The main difference. The relief valve 12 is connected to the hydraulic pump 4 and the solenoid valve 1.
Instead of being directly connected in the middle of the pipeline connecting
It is connected via the solenoid valve 8A of the port.
When the winch 20A is used as an auxiliary winch for cargo handling, the counterbalance 62 is for preventing the suspended load from falling by its own weight even when the hydraulic pump 4 is stopped while the suspended load is being lifted. . In the hydraulic drive circuit shown in FIG. 6, one of the relief valve 10 (relief pressure Pb) and the relief valve 12 (relief pressure Pa) is connected to the hydraulic pump 4 and the solenoid valve 14 in accordance with the switching state of the solenoid valve 8A. Communicates with the pipeline connecting. Therefore, unlike the one shown in FIG.
And Pb can be set arbitrarily. For example, when the relief work (relief pressure Pa) and the auxiliary winch operation (relief pressure Pb) are used for both the relief work and the auxiliary winch operation as in the present embodiment, the relief pressure Pb for the relief operation is set higher than the relief pressure Pa for the auxiliary winch. It is also possible.

In FIG. 6, when the solenoid valve 14 is located at the switching position C, the hydraulic oil discharged from the hydraulic pump 4 flows into the port 22a of the hydraulic motor 22 through the check valve 62b. On the other hand, when the solenoid valve 14 is located at the switching position B, the hydraulic oil discharged from the hydraulic pump 4 flows into the port 22b of the hydraulic motor 22. At this time, the pilot pressure connection line 6
When the internal pressure of 2d increases, the relief valve 62a is relieved,
The hydraulic oil flows from the port 22a to the tank 1, and the hydraulic motor 22 rotates. When the solenoid valve 14 is at the switching position A, the relief valve 62a of the counter balance 62 is in a closed state. Therefore, even if the solenoid valve 14 is switched to the switching position A while the suspended load is suspended, the suspended load does not drop by the action of the brake 24 and the counter balance 62.

FIG. 7 shows a winch changeover switch SW1 and a hoisting / lowering operation switch S similar to those shown in FIG.
Solenoid valves 8A, 14 corresponding to the switching state of W2
And 16 show how the switching positions are switched, so that the relief pressure, the operation of the hydraulic motor 22 and the brake 24 are switched.
As shown in FIG. 7, the relief pressure is set to Pa by switching the winch changeover switch SW1 to the "leaving winch" side.
By switching W1 to the "auxiliary winch" side, the relief pressure is set to Pb. Winch switch SW
By operating the hoisting / unwinding operation switch SW2 in the state where 1 is switched as described above, one winch 20 can be used as a winch for the leaving work or as an auxiliary winch.

Second Embodiment A second embodiment of the present invention also shows an example in which the hydraulic drum drive is used for both a hydraulic tag line and a leaving winch. In the first embodiment, an example has been described in which a plurality of relief valves having different relief pressure set values are switched and used in order to set different upper limit torques according to the purpose of use. In the second embodiment, an example in which the upper limit torque is set using a variable displacement hydraulic motor will be described.

In FIG. 8, which schematically shows a hydraulic drive circuit for driving the winch, the winch 20B can be used also as a winch for a leaving winch and a winch for a hydraulic tag line. In FIG. 8, the same components as those in FIG. 1 showing the hydraulic drive circuit according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The winch 20B includes a brake 24, a variable displacement hydraulic motor 22A, a drum 26, a regulator 63, and a controller 64. In the present embodiment, the variable displacement hydraulic motor 22A is simply referred to as “hydraulic motor 22A”.

The voltage B is applied to the terminal 64a or 64b of the controller 64 in accordance with the switching state of the winch switch SW1. The controller 64 includes a terminal 64a
When the voltage B is applied to the regulator 63, a control signal is issued to the regulator 63 so that the displacement volume of the hydraulic motor 22A becomes the predetermined capacity Qa. A control signal is issued so that the displacement of the motor 22A becomes the predetermined displacement Qb. The pushing capacities Qa and Qb are set so that Qa> Qb. Here, the relationship between the displacement Q of the hydraulic motor 22A and the torque T generated from the hydraulic motor 22A will be described. These relationships are obtained by the following equation (1).

(Equation 1)

As is apparent from the equation (1), the upper limit of the torque T generated by the hydraulic motor 22A is proportional to the set displacement Q. That is, the regulator 63
By changing the displacement Q, the upper limit torque of the hydraulic motor 22A can be made variable.

As described above, since the upper limit of the torque T generated by the hydraulic motor 22A can be changed by the regulator 63, it is necessary to select one of the relief valves 12 and 10 as shown in FIG. The solenoid valve 8 (above, FIG. 1) is not required. Therefore, in FIG. 8, the relief valve 12A of the relief pressure Pc is used.
Is mounted directly in the middle of a pipe connecting the hydraulic pump 4 and the solenoid valve 14. That is, the hydraulic motor 2
The upper limit pressure (relief pressure) of the hydraulic oil flowing into 2A is always set to Pc.

In the hydraulic drive circuit configured as described above, the voltage B is applied to the terminal 64a of the controller 64 when the operator switches the winch changeover switch SW1 to the "leaving winch" side. In response to this, the controller 64 issues a control signal to the regulator 63 so that the displacement volume of the hydraulic motor 22A becomes the predetermined volume Qa. As a result, the displacement of the hydraulic motor 22A is set to Qa. When the operator operates the hoisting / unwinding operation switch SW2 to the "hoisting" side, the solenoid valves 14 and 16 are switched to the switching positions C and B, respectively, as shown in FIG. When released, the winch 20B moves upward. The upper limit torque of the hydraulic motor 22A at this time is Pc, Qa and ηa (where ηa is P =
Pc, which represents the operating efficiency when Q = Qa). On the other hand, when the operator operates the hoist / lower operation switch SW2 to the "lower" position, the solenoid valves 14 and 16 are both switched to the switching position B as shown in FIG. 9B, and the brake 24 is released. Then, the winch 20B operates to the lower side. The upper limit torque of the hydraulic motor 22A at this time is also Ta. In addition, although a large load is basically not applied to the hydraulic motor 22A during the lowering, considering the case where the drum 26 cannot be rotated due to some trouble or the like, the above-described upper limit torque is also used during the lowering. It is effective to set

As described in the description of the first embodiment, the hoisting / lowering operation switch SW2 is a momentary switch, and returns to the neutral position when the operator releases his / her hand from the switch. At this time, the solenoid valves 14 and 1
6 is switched to the switching position A as shown in FIG. 9C, the hydraulic oil stops flowing into the hydraulic motor 22A, the brake 24 is operated, and the hydraulic motor 22A stops rotating.

When the operator switches the winch changeover switch SW1 to the "hydraulic tag line" side, the controller 6
The voltage B is applied to the fourth terminal 64b. Controller 6
4 responds to this by issuing a control signal to the regulator 63 so that the displacement volume of the hydraulic motor 22A becomes the predetermined volume Qb. As a result, the displacement of the hydraulic motor 22A is set to Qb. In this state, when the operator operates the tag line operation switch SW3 to the “ON” side, the solenoid valves 14 and 16 are switched to the switching positions C and B as shown in FIG. 9D, and the brake 24 is released. Then, the winch 20B moves to the upper side of the winding. At this time, the upper limit torque of the hydraulic motor 22A is Pc, Qb and ηb (ηb
Represents the operating efficiency when P = Pc and Q = Qb). This upper limit torque Tb is
Set the winch changeover switch SW1 to "Leaving winch"
Is relatively smaller than the upper limit torque Ta set for the hydraulic motor 22A when switching to the side. The reason is as described in the description of the first embodiment. When the tension of the tag line rope (not shown in the present embodiment) wound around the drum 26 increases so as to exceed the upper limit torque Tb of the hydraulic motor 22A, the drum 26 rotates to the lower side, and the hydraulic motor 22A Acts as a hydraulic pump. At this time, the internal pressure of the pipeline connected between the hydraulic pump 4 and the solenoid valve 14 increases, but is relieved by the relief valve 12A (relief pressure Pc).

When the operator operates the tag line operation switch SW3 to the "OFF" side in a state where the winch changeover switch SW1 is switched to the "hydraulic tag line" side, the solenoid valves 14 and 16 are turned to (e) in FIG. ), The positions are switched to the switching positions A and B, respectively, and the brake 24 is released, so that the hydraulic oil does not flow into the hydraulic motor 22A. In this state, the drum 26 can freely rotate in an arbitrary rotation direction, and the tag line rope wound around the drum 26 can be manually pulled out or wound.

As described above, according to the hydraulic drum driving device according to the second embodiment, the hydraulic motor 22
By changing the displacement of A, the upper limit torque according to the purpose of use can be easily switched, and one hydraulic drum drive can be used for a plurality of purposes. For this reason, the installation space of the hydraulic drum device can be reduced, and the manufacturing cost can be reduced. Further, since the upper limit torque of the hydraulic drum driving device is automatically switched in conjunction with the switching of the winch switch SW1, there is no need to adjust the upper limit torque or check the set value. Further, it is possible to prevent the upper limit torque that does not suit the purpose of use from being erroneously set, thereby preventing the device from malfunctioning or accident.

In the correspondence between the above-described embodiment and the claims, the winch changeover switch SW1 functions as an operation mode switching means by a combination of the relief valves 10 and 12 and the solenoid valve 8 (see FIG. 1), a relief valve 1
The combination of the solenoid valves 0 and 12 and the solenoid valve 8A (see FIG. 6) and the combination of the controllers 64 and 63 hydraulic motor 22A (see FIG. 8) constitute the upper limit torque switching means.

[0057]

As described above, (1) According to the first aspect of the present invention, the upper limit torque of the hydraulic motor is switched according to the switching of the operation mode so as to correspond to a plurality of different applications. Therefore, it is not necessary to adjust the upper limit torque of the hydraulic motor or to check the set upper limit torque every time the usage is changed, and the workability is excellent. In addition, the upper limit torque that is not suitable for the intended use is not erroneously set, so that a failure or accident of the device can be prevented. (2) According to the second aspect of the present invention, by using the hydraulic drum driving device as the auxiliary winch, two loading and unloading operations can be performed by one crane, and the operation becomes efficient, and at the same time, the counter is used. By having the balance valve, even if the hydraulic drive actuator stops for some reason, the suspended load can be prevented from dropping by its own weight, and an accident can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a hydraulic drive circuit of a hydraulic drum drive device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing how the operation mode of the hydraulic drum device according to the first embodiment of the present invention is switched in accordance with the switching state of a switch.

3A and 3B are diagrams illustrating an example in which the hydraulic drum driving device according to the first embodiment of the present invention is used for a leaving operation, wherein FIG. 3A illustrates an initial operation state, and FIG. This shows a state in which winding around the sheave and the guide sheave has been completed.

FIG. 4 (a) shows a state in which the leaving wire is wound up to complete the winding of the main wire around the guide sheave, point sheave and hook sheave, as in FIG.
(B) is a figure which shows the state which completed the leaving operation.

FIG. 5 is a diagram showing an example in which the hydraulic drum driving device according to the first embodiment of the present invention is used as a device for a hydraulic tag line.

FIG. 6 is a diagram showing an example in which one use purpose of the hydraulic drum driving device according to the first embodiment of the present invention is an auxiliary winch for hanging loads.

7 is a diagram showing how the operation mode of the hydraulic drum driving device having the hydraulic driving circuit shown in FIG. 6 is switched in accordance with the switching state of the switch.

FIG. 8 is a diagram illustrating a hydraulic drive circuit of a hydraulic drum drive according to a second embodiment of the present invention.

FIG. 9 is a diagram showing how the operation mode of the hydraulic drum driving device according to the second embodiment of the present invention is switched according to the switching state of the switch.

[Explanation of symbols]

4,6 Hydraulic pump 8,8A, 14,16 Solenoid valve 8S, 8AS, 14S1,14S2,16S solenoid 10,12,12A Relief valve 20,20A, 20B Winch 22 Hydraulic motor 22A Variable displacement hydraulic motor 24 Brake 26 Drum 40 Main winding winch 42 Main wire 44 Leaving wire 44A Tag line rope 48 Hook sheave 50 Point sheave 52 Guide sheave 58 Boom SW1 Winch switch SW2 Hoisting / Unwinding operation switch SW3 Hydraulic tag line operation switch

Claims (2)

[Claims] 1. A hydraulic motor for driving a drum which draws in and pulls out a rope, operation mode switching means for switching operation modes of the drum so as to correspond to a plurality of different applications, and a switching state of the operation mode switching means. An upper limit torque switching means for switching the upper limit torque of the hydraulic motor in response to the change. 2. The hydraulic drum driving device according to claim 1, further comprising a counterbalance valve connected to the hydraulic motor, wherein one of the plurality of different uses is for cargo handling. A hydraulic drum drive, characterized in that it is an auxiliary winch.