JP4659949B2 - Load detection device in lifting equipment using multiple hoists - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for detecting the total load applied to each rope in a lifting equipment for lifting one piece of luggage with a plurality of hoists.
[0002]
[Prior art]
When lifting important loads with hoists, multiple hoists, generally two hoists are used, one hoist breaks down, one rope breaks, etc. Lifting equipment that can be lifted by a rope is widely known.
[0003]
In addition, when a load exceeding the set value is applied to the hoist when lifting the load, it is necessary to take safety measures such as stopping the lifting or issuing an alarm, and for that purpose, a device that detects the load applied to the rope is provided. It is also widely known, for example, in a hoist with a low lift and using a sheave as a moving pulley, the load applied to the fixed end of the rope fixed in place on the hoist and the load applied to the tip side of the rope load Have been put to practical use with a load detection device installed at the fixed end.
[0004]
[Problems to be solved by the invention]
However, in a hoist for a high head that does not use a moving pulley, the rope is not fixed at an appropriate position of the hoist, so the load applied to the rope cannot be directly detected. In addition, when the environment where the hoist is installed is a place where flammable gas or dust is contained and needs explosion-proof, or where it is exposed to wind and rain and requires waterproofing, there is a risk of ignition or electric leakage. The load detection device cannot be used.
[0005]
Furthermore, in the lifting equipment that lifts one piece of cargo with multiple hoists, it is necessary to detect whether the load applied to the hoist is less than or equal to the set value by detecting the load applied to each rope and obtaining the total. However, it is inevitable that the entire system becomes complicated because a load detecting device is provided for each rope and a means for summing up the detected values is provided. In addition, as described above, there is a limitation that an electric type cannot be used in an environment that requires complete explosion-proofing and waterproofing.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a load detection device that solves such problems and detects a load applied to each of a plurality of hoist ropes and adds them with a non-electrical and simple configuration. It is.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention has the following load detecting device for lifting equipment that uses a plurality of hoists having a prime mover, a speed reducer, and a winding drum to lift one piece of luggage with these ropes. .
[0008]
That is, a load detection hydraulic cylinder is attached to each of the plurality of hoists, and one load adder that operates when the hydraulic pressure generated by these load detection hydraulic cylinders exceeds a set value, and is operated by this load adder. And a sensor for emitting a signal. And the portion of the hoist that receives the rotational reaction force of each reduction gear cannot be rotated in the rope winding direction but can be rotated in the rope feeding direction, and the load is detected by the rotational force in the rope feeding direction of the portion that receives the rotational reaction force The hydraulic cylinder was activated.
[0009]
The load of the load on which the rope is hung can be determined by the rotational force of the winding drum. The rotational force of the winding drum and the rotational force of the reduction gear are the same, and the rotational force of the outer frame of the reduction gear and the output shaft are also the same. Therefore, it is possible to indirectly measure the load of the load by measuring the rotational force as being able to rotate without fixing the outer frame or the output shaft that receives the rotational reaction force of the speed reducer. .
[0010]
By using this and hydraulic pressure, the present invention detects the load applied to each of the ropes and adds them together with a non-electrical and simple configuration, and appropriately generates a signal when the set value is exceeded. Made it possible.
[0011]
In carrying out the present invention, the output shaft of the speed reducer is used as the rotational reaction force receiving portion, and the outer frame is fixed to the winding drum and is rotated in the rope winding and feeding direction, and a lever is attached to the output shaft. It is preferable that the lever is prevented from rotating in the rope winding direction by the stopper and the load detecting hydraulic cylinder is operated by the rotational force in the rope feeding direction.
[0012]
Similarly, in carrying out the present invention, the load adder includes a load acting hydraulic cylinder in which a load adder is individually connected to each load detecting hydraulic cylinder, one direct acting member, and a spring. It is preferable that the piston and the spring are opposed to each other.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. A frame 1 is fixed in a suspended state to a carriage B on which wheels run on a lower end flange of a shape steel A, and two frames are attached to the frame 1. The hoists 2 and 2 are held parallel to each other at a position where the section steel A is sandwiched.
[0014]
The hoist 2 has a prime mover 3 and a speed reducer 4 that are arranged on the same central axis and have an output shaft and an input shaft coupled to each other, and a winding drum 7 that surrounds the speed reducer 4 and is concentrically disposed therewith. In the speed reducer 4, the outer frame 5 is fixed to the frame 1 and the winding drum 7 is rotated by the output shaft 6. In the present embodiment, the outer frame 5 is attached to the winding drum 7 by bolts 8. The output shaft 6 is fixed with a lever 9 by key connection and is rotatably supported by a bearing 10 on the front wall 1A of the frame 1. The winding drum 7 has an outer frame 5 fixed at one end on the output shaft 6 side, and is attached to the rear wall 1B of the frame 1 to attach the prime mover 3 and at the other end to a boss 11 passing through the output shaft. The part is supported by the bearing 12. Thereby, the winding drum 7 rotates on the same central axis as the prime mover 3 and the speed reducer 4 and winds or feeds the rope 13.
[0015]
The two hoists 2, 2 extend the ropes 13, 13 close to each other from their opposite sides and extend downward in parallel, and the two hoists 2, 2 are rotated by rotating the winding cylinders 7 in opposite directions. The ropes 13 and 13 are simultaneously wound or unwound, and the load 15 hung on the hook 14 attached to the tip of the ropes 13 is lifted or lowered to the destination.
[0016]
The lever 9 can rotate on the outer side of the front wall 1A on a plane parallel to the lever. If the winding cylinder 7 rotates in the rope winding direction, the output shaft 6 and the lever 9 rotate integrally. Therefore, the stopper 17 made of an adjusting screw is provided on the front wall 1A to prevent the rotation, and the lever 9 receives the rotational reaction force of the speed reducer 4.
[0017]
The outer frame 5 and the winding drum 7 of the speed reducer 4 generate a rotational force in the rope feeding direction when the load 15 is lifted, and a rotational force is also generated in the output shaft 6 and the lever 9. A load detection hydraulic cylinder 21 is installed on the front wall 1A so as to face the stopper 17 with the lever 9 interposed therebetween on the side that rotates in the rope feeding direction. The load detection hydraulic cylinder 21 has the tip of a piston rod 24 extending from a piston 23 fitted to the cylinder cylinder 22 in contact with the lever 9 and fills the cylinder chamber 25 opposite to the piston rod 24 with hydraulic oil. Yes.
[0018]
One load adder 27 is attached to the front wall 1A. This load adder 27 is provided with two cylinder chambers 30 in parallel on a lid 29 that closes one end of a cylindrical housing 28, and a piston 31 is fitted to each of them, and a tip end portion of a piston rod 32 extending therefrom. Are protruded into the housing 28, and the back surface portion of the piston 31 of the cylinder chamber 30 is connected by the cylinder chamber 25 and the hose 26 of the two load detection hydraulic cylinders 21 to fill them with hydraulic oil. Further, a disc-like linearly moving member 33 is fitted in the housing 28, and an operating rod 34 extending therefrom is inserted through the plug 35 screwed to the other end of the housing 28 so as to protrude outside. Further, the tips of the two piston rods 32 are brought into contact with one surface of the linear motion member 33, and the compression coil spring 36 inserted between the plug 35 is applied to the other surface.
[0019]
The initial load of the spring 36 can be adjusted by the screwing amount of the plug 35. When the force with which the two piston rods 32 push the linear motion member 33 is larger than the force of the spring 36, the operating rod 34 operates the sensor 38. A signal is emitted. The sensor 38 may be a limit switch, but it is preferable that the sensor 38 is composed of a three-port mechanically operated directional switching valve and uses fluid on / off as a signal. It is attached to the wall 1A.
[0020]
When the load 15 is lifted, the two ropes 13 and 13 basically bear the load equally, but if one is loose, the other will bear the full load. Therefore, the total load applied to the two ropes 13 and 13 is always detected, and when the total load exceeds the set value, either one or two bears the load. Even under certain circumstances, it is necessary to take safety measures such as stopping lifting or issuing an alarm.
[0021]
When the load 15 is being lifted, a rotational force in the rope feeding direction is generated in the winding drum 7. At this time, the lever 9 comes into contact with the piston rod 24 of the load detection hydraulic cylinder 21 to receive a rotational reaction force and is fixed. It has become a state. Here, the load applied to the rope 13 is W, the rope center radius of the winding drum 7 is R, the distance from the rotation center of the lever 9 to the contact point with the piston rod 24 is L, and the force generated at the contact point is F. WR = FL holds, and the piston 23 is pushed by the force F to pressurize the hydraulic fluid in the cylinder chamber 25, the hose 26, and the cylinder chamber 30.
[0022]
The force that pushes the piston 31 of the load adder 27 is determined by the area ratio between the piston 31 and the piston 23 of the load detection hydraulic cylinder 21 and the force F that pushes the piston 23, and each of the winding cylinders 7 of the two hoists 2. A load applied to the rope 13 is applied to the corresponding piston 31 of the load adder 27 so that these piston rods 32 push the linear motion member 33. Therefore, the total load of the loads applied to the two ropes 13 and 13 is applied to the linear motion member 33, and even when one rope is loose, another one rope bears the total load. Therefore, the total load still works on the linear motion member 33.
[0023]
When the force pushing the linear motion member 33 is larger than the load set by the spring 36, the operating rod 34 operates the sensor 38 to generate a signal. This signal acts to rotate the winding drum 7 so as to stop the lifting of the load 15 and drop it on the ground or the floor, or issue an alarm.
[0024]
When the output shaft 6 of the speed reducer 4 is coupled to the winding drum 7 and the winding drum 7 is rotated as usual, the outer frame 5 can be rotated and components corresponding to the lever 9 are attached, and the stopper 17 And the load detection hydraulic cylinder 21 are sandwiched with parts corresponding to the lever 9 to perform the same rope load detection as described above. Therefore, the mechanism can be made compact by receiving the rotational reaction force at the output shaft 6 as in the present embodiment.
[0025]
【The invention's effect】
As described above, according to the present invention, a determination as to whether or not the set value is exceeded by adding the loads shared by the ropes of the plurality of hoists is made using a non-electrical force utilizing the rotational reaction force and hydraulic pressure of the speed reducer. With a simple configuration, it can be performed accurately and can be used safely even in environments that require complete explosion-proofing and waterproofing.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is an enlarged partial sectional view of FIG.
FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG.
[Explanation of symbols]
1 frame, 2 hoist, 3 prime mover, 4 speed reducer, 7 winding drum, 9 lever, 13 rope, 17 stopper, 21 load detection hydraulic cylinder, 23 piston, 27 load adder, 30 cylinder chamber, 31 piston, 33 straight Moving members, 36 springs, 38 sensors,

Claims (3)

In a lifting facility that uses a plurality of hoists with a prime mover, a reducer, and a winding drum to lift one piece of luggage with their ropes,
A load detection hydraulic cylinder attached to each of the plurality of hoists, a load adder that operates when the hydraulic pressure generated by each load detection hydraulic cylinder exceeds a set value, and the load adder And a sensor that emits a signal when
The portion that receives the rotational reaction force of each speed reducer cannot rotate in the rope winding direction but can rotate in the rope feeding direction, and the load detection hydraulic cylinder can be rotated by the rotational force in the rope feeding direction of the rotational reaction force receiving portion. Was activated,
A load detection device characterized by that. The output shaft of the speed reducer is the rotational reaction force receiving portion, and the outer frame is configured to consolidate the winding drum and rotate in the rope winding and feeding direction, and a lever is attached to the output shaft. 2. The load detecting device according to claim 1, wherein the lever is prevented from rotating in a rope winding direction by a stopper and the load detecting hydraulic cylinder is operated by a rotational force in a rope feeding direction. The load adder includes a load responsive hydraulic cylinder individually connected to each load detection hydraulic cylinder, a single linear motion member, and a spring. The linear motion member includes a piston and a spring of each load responsive hydraulic cylinder. 2. The load detection device according to claim 1, wherein the load detection device is operated oppositely.

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