JPS6127910Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention includes a wire drum in which a hydraulic pump and a hydraulic motor are connected through a forward rotation line and a reverse rotation line, and which operates in conjunction with the hydraulic motor driven by the hydraulic pump. This invention relates to an emergency lowering device for a cargo handling machine that has an auxiliary brake device on its wire drum or hydraulic motor.

Various types of such cargo handling machines are known, in which a hydraulic motor driven by a hydraulic pump rotates a wire drum that is coupled directly or through a gear system to the hydraulic motor and operates in conjunction with the hydraulic motor, thereby transferring the load. winding and lowering. However, if a power outage occurs while the load is hoisted, the hydraulic pump will not be driven, so there is a risk that the load will fall freely. For this purpose, according to the prior art, a brake device is provided, or a device is used that uses a solenoid valve to shut off the oil path through which the liquid flows when free falling during a power outage. However, in this case, there is a risk that the hoisted load may fall due to, for example, a leak in the oil passage.

For example, Japanese Patent Publication No. 49-38340 provides an actuation device that engages the auxiliary brake when no hydraulic pressure is applied, and when it is desired to allow the load to fall freely, the clutch disconnects the driving relationship between the hydraulic motor and the drum. A device is disclosed in which the load is gradually dropped. However, in this known technique, the driving relationship is severed during a free fall, which poses a safety problem.

In addition, Utility Model Publication No. 50-118694 discloses that the hydraulic pump is driven by an engine when lifting the anchor, and is used only when dropping the anchor, and detects the anchoring speed and proportionally controls the discharge pressure of the hydraulic pump to prevent runaway when lifting the anchor. A device for preventing this is disclosed, and in this known technique, the pressure supplied to the handbrake cylinder is also adjusted in proportion to the anchoring speed to adjust the clamping force. However, even if such technology is applied to cargo handling equipment, unlike in the case of anchoring, the safety of the load must be confirmed while allowing it to fall freely, so the clamping force acts as a braking force in proportion to the falling speed of the load. I can't let you.

Therefore, the purpose of the present invention is to provide an emergency lowering device for a cargo handling machine that can lower the load slowly and safely without disconnecting the drive device and the load in an emergency such as when the hydraulic pump stops due to a power outage. It is on offer.

According to the present invention, a branch line connecting the forward rotation line and the reverse rotation line is provided, a device for controlling the lowering speed is provided on the branch line, and the braking is performed by applying pressure oil to the auxiliary brake device. An emergency hydraulic pump that can be rotated manually is connected to the brake line that applies pressure oil to the auxiliary brake device, and the discharge line of the emergency hydraulic pump is connected to a branch line. is also connected.

Therefore, when a power outage occurs during the hoisting operation, no pressure oil is generated in the brake line, so the auxiliary brake is activated and the load is stopped in the hoisted state. Then, by manually rotating the emergency hydraulic pump and supplying pressure oil to the brake line, the brake is loosened, the hydraulic motor rotates due to its own leakage, and the load is slowly lowered.

In this way, the load and the drive hydraulic motor are always connected, allowing safe work at all times, and in the event of emergency lowering, the speed can be adjusted using a lowering speed control device installed on the branch line. And since an emergency hydraulic pump is used to release the brakes, the required amount and pressure of oil can be maintained. Therefore, the hydraulic motor and load are not separated, and all you have to do is turn the independently installed emergency hydraulic pump, supply oil to the brake line, and release the brake, allowing the load to be lowered safely and slowly in an emergency. be able to.

When carrying out the present invention, a variable throttle/stopper may be used as the device for controlling the lowering speed, and its structure is simple. Further, when the amount of leakage from the hydraulic motor is small and the lowering speed of the load is slow, a device for controlling the lowering speed may be provided. As a device for controlling the lowering speed, a variable throttle/stop valve or a hydro valve can be used.

When the hydrovalve is implemented as a device for controlling the lowering speed, the lowering of the load can be automatically stopped when the lowering speed of the load exceeds a certain value.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a hydraulic pump 1 is of a variable displacement type driven by a motor M, and by supplying pressure oil to a normal rotation line 2, a hydraulic motor 4 rotates in the normal direction, and a reverse rotation line 3 By supplying pressure oil to the hydraulic motor 4, the hydraulic motor 4 is configured to rotate in the reverse direction. The hydraulic motor 4 is a known two-speed type that can be switched between high-speed, low-torque operation and low-speed, high-torque operation by a valve 5, and the wire drum 6 is rotated by the hydraulic motor 4. It's becoming like that. However, the hydraulic motor 4 is not particularly limited to a two-speed type, and any hydraulic motor can be implemented; however, in order to make the explanation easier to understand, a two-speed type will be described in the illustrated embodiment. A wire 8 for moving a load 7 is wound around the wire drum 6, and the load 7 is wound up when the hydraulic motor 4 rotates in the normal direction and lowered when the hydraulic motor 4 rotates in the reverse direction. In the figure, reference numeral 9 denotes an auxiliary brake device, and the auxiliary brake device 9 releases the brake when pressure oil is applied to the brake line 10 by a hydraulic power source (not shown) provided at a predetermined position on the brake line 10. It's becoming like that. A stopper 11 is provided to control the tightening condition of the brake when pressure oil is applied to the cylinder of the auxiliary brake device 9. By adjusting the position of this stopper 11, the piston of the auxiliary brake device 9 is tightened. This is to limit the stroke amount and optimize the braking force. For example, with a winch that carries a high load of several tens of tons, the brake is not fully released and the brake force is set to zero to lower the winch, but rather a constant brake force is always applied. In addition, the braking force may be changed between normal lowering and emergency lowering, so in such cases, stopper 11
Just adjust the position of. 12 is a solenoid valve which is in the position shown when the motor M is stopped;
It is designed to close the pressure oil line. During normal hoisting or lowering, this solenoid valve 12 is located at a cross position (opposite position to that shown in the figure), and connects the forward rotation line 2 to the discharge port or suction port of the pump 1 (depending on the tilt angle). ), and the pump 1 and motor 4 are drivingly coupled. When the pump 1 is stopped or in an emergency, the solenoid valve 12 is not energized and is in the parallel position shown in the drawing. Therefore, normal rotation line 2 is blocked,
For this reason, the oil in the forward rotation line 2, reverse rotation line 3, and hydraulic motor 4 cannot move, and even if there is an abnormality in the brake device, the free fall of the load will not be prevented. Although the illustrated embodiment has been described as a closed circuit, it is clear that the present invention can also be applied to an open circuit incorporating a known counterbalance valve or the like.

All of the above essentially belong to known techniques.

Now, according to the present invention, a branch line 13 is provided in the forward rotation line 2, and in the illustrated embodiment, this line
3 is connected to the brake line 10. Also, the emergency hydraulic pump 15 is connected to the brake line 10.
is connected. This emergency hydraulic pump can be driven manually in the event of a power outage, and is supplied with oil from the tank T via the oil supply line 16.
Oil pressurized by the emergency hydraulic pump 15 is supplied to the auxiliary brake device 9 via the step valve C and the brake line 10. Further, a stop valve 17 is provided between the brake line 10 and the reverse rotation line 3, and the brake line 10 is connected to the stop valve 1.
It is connected to tank T via 8. 19 in the diagram
is a pressure gauge.

Next, the lowering work during a power outage will be explained. At this time, the solenoid valve 12 is in the position shown, pressure oil from a pressure oil source (not shown) is not applied to the auxiliary brake device 9, the stop valve 17 is closed, and the stop valve 18 is opened and drained. , a braking action is occurring on the winch drum 6. Therefore, the load 7 is stopped in a hoisted state. Further, at this time, since the reverse rotation torque due to the load 7 is absorbed by the auxiliary brake device 9, no oil pressure is generated in the forward rotation line 2.

Therefore, the variable throttle/stop valve 14 is kept closed, the stop valve 17 is opened, and the stop valve 18 is closed. In this state, the auxiliary brake device 9 is still not released, so the hydraulic motor 4 cannot rotate. Next, the emergency hydraulic pump 15 is manually rotated. At this time, while watching the pressure gauge 19, if an appropriate pressure, for example, 6 to 10 kg/cm ² of hydraulic pressure is supplied to the line 20, it will communicate with the line 10, and the spring inside the cylinder of the auxiliary brake device 9 and the supplied hydraulic pressure will be balanced. The cylinder rod moves until the brake is released and the hydraulic motor 4 is allowed to rotate by its own leakage, so that the load 7 drops. At this time, the emergency hydraulic pump 15 not only releases the auxiliary brake device 9 but also replenishes leakage from the hydraulic motor 4. At this time, a pressure corresponding to the load is generated in the line 13. At this time, when the descending speed is slow, the variable throttle/stop valve 14 may be opened gradually while paying attention to the movement of the load. When this variable throttle/stop valve is opened, the pressure oil generated in the normal rotation line 2 can be circulated through the branch line 13, the variable throttle/stop valve 14, and the stop valve 17, so that the hydraulic motor 4 can be operated as a variable throttle/stop valve. It can rotate at a rotational speed controlled by a stop valve 14. The load 7 is therefore lowered at a safe lowering speed. Further, lowering can be performed safely while rotating the pump 15 forward and backward to loosen or tighten the brake device 9.

As described above, according to the present invention, the load can be lowered safely by manually rotating the emergency hydraulic pump 15 during a power outage.

The embodiment of the invention shown in FIG. 2 is substantially the same as the embodiment of FIG. 1, and corresponding elements are designated by the same reference numerals. In the embodiment shown in FIG. 1, while the load 7 is lowering, the emergency hydraulic pump 15 is manually rotated in order to ensure the hydraulic pressure to keep the auxiliary brake device 9 released and the hydraulic pressure to replenish the leakage of the hydraulic motor 4. However, in the embodiment shown in FIG. 2, if the emergency hydraulic pump 15 is first rotated until the auxiliary brake device 9 is released, then it will continue to rotate automatically without manual intervention. It is becoming possible to be

In the embodiment of FIG. 2, the emergency hydraulic pump 15
is connected to another hydraulic motor 21, and the circuit of the hydraulic motor 21 is provided with a throttle valve 22, which connects the branch line 13 and the brake line 1.
0 is connected to the circuit of the other hydraulic motor via a stop valve V and a hydro valve 23 which is a three-position switching valve. This hydro valve 23 is placed in the cutoff position shown in the figure by the hydraulic pressure in the pilot line 25 from the motor side of the throttle valve 22, and the ports A, P, and B are opened by the hydraulic pressure in the pilot line 24 from the branch line 13. They are arranged in parallel positions connecting the respective R's.

In operation, when the stop valve V is opened and the emergency hydraulic pump 15 is rotated manually as described above, pressure oil is applied to the brake line 10, the brake device 9 is loosened, and the pressure in the normal rotation line 2 corresponds to the load. occurs. The pressure in the branch line 13 therefore increases, so that the pressure in the pilot line 24 causes the hydrovalve 23 to switch to the parallel position. As a result, the other hydraulic motor 21 is rotated, and the directly connected hydraulic pump 15 is also rotated.
Since pressure oil continues to be automatically supplied to the brake device 9 and the amount of leakage from the hydraulic motor 4 continues to be replenished to the line 3, the load is safely lowered.

When the rate of descent of the load exceeds a certain value and becomes dangerous, the rotational speed of another hydraulic motor 21 also exceeds the certain value, and the pressure upstream of the throttle valve 22 increases. Therefore, the hydraulic oil from the pilot line 25 brings the hydro valve 23 to the illustrated shutoff position, stopping the load from dropping. This hydro valve 23 is structured so that it can only be switched between the parallel position and the shutoff position under pilot pressure. In addition, in this embodiment, if an abnormal situation occurs, the hydro valve can be switched to port A using the emergency lever.
If the hydraulic pump 15 is moved to the cross position where ports B and P are connected, the hydraulic pump 15 will rotate in the opposite direction.
Since the brake device 9 is engaged, sudden braking can be applied.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a circuit diagram showing another embodiment. 1... Hydraulic pump, 2... Normal rotation line, 3...
Reverse line, 4...Hydraulic motor, 7...Load, 9
... Auxiliary brake device, 10 ... Brake line, 13 ... Branch line, 14 ... Variable throttle and stop valve, 15 ... Emergency hydraulic pump, 21 ...
Another hydraulic motor, 22... throttle valve, 23... hydro valve.

Claims (1)

[Scope of utility model registration request] A hydraulic pump and a hydraulic motor are connected by a forward rotation line and a reverse rotation line, and a wire drum is provided that operates in conjunction with the hydraulic motor driven by the hydraulic pump, and an auxiliary brake device is provided on the wire drum and the hydraulic motor. In the emergency lowering device of a cargo handling machine that has A brake line is provided to release the brake by applying pressure, and an emergency hydraulic pump that can be rotated manually is connected to the brake line for applying pressure oil to the auxiliary brake device. An emergency lowering device for a cargo handling machine, characterized in that the discharge line is also connected to a branch line.