JPS5924072B2 - Telescopic boom in cargo handling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telescoping boom in a cargo handling device.

The boom of cargo handling equipment has a wide range of cargo handling, and the larger the lifting range of the cargo, the more useful it is, so it is generally constructed to be extendable and retractable so that the length of the boom can be adjusted as needed. .

The present invention provides such a telescopic boom with separate sliding movement devices for sliding the middle cylinder with respect to the base cylinder and the inner cylinder with respect to the middle cylinder in the telescopic direction, and these sliding movement devices A telescopic boom length detecting device provided on the boom controls the operation according to the telescopic length of the telescopic boom, so that the telescopic boom is extended in a predetermined order.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained below based on one embodiment shown in the accompanying drawings.

Reference numeral 1 denotes a traveling machine base of a mobile cargo handling device, and the machine base 1 is provided with a swivel base 2 so as to be able to turn in a direction of 360 degrees around a vertical axis, and also stably supports the traveling machine base 1 during cargo handling operations. Equipped with outrigger 3.

A telescopic boom 4 is pivotally attached to the swivel base 2 at the base end of its base cylinder 5 via a horizontal axis so as to be movable up and down, and between the middle part of the base cylinder 5 and the appropriate position of the swivel base 2. A telescopic hydraulic hoist 6 is interposed such that its upper and lower ends are rotatable, and the telescopic boom 4 is moved up and down by the telescopic operation of the hydraulic hoist 6.

A wire rope 8 attached to a winch device 7 disposed at a suitable position on the swivel base 2 is suspended from the tip of the telescopic boom 4 to suspend the load. A counterweight 9 for stabilizing the cargo handling operation is provided on the opposite side of the extension side of the telescopic boom 4.

The telescopic boom 4 is connected to the base cylinder 5 in the first position.
The middle cylinder 10, the second middle cylinder 11, and the inner cylinder 12 are configured to be slidably and telescopically fitted in order in order, and the two adjacent cylinders are slidably inserted between each part. A sliding motion device for moving and expanding/contracting is interposed.

That is, a first double-acting hydraulic hoist 13 is provided between the base tube 5 and the first middle tube 10, and a second double-acting hydraulic hoist 14 is provided between the first middle tube 10 and the second middle tube 11. Furthermore, a third double-acting hydraulic hoist 15 is interposed between the second middle cylinder 11 and the inner cylinder 12, and each joint is relatively slidably moved by the expansion and contraction of each double-acting hydraulic hoist. A telescopic boom 4 is adapted to be extended and contracted.

FIG. 3 is an operating circuit diagram of each of the above double-acting hydraulic hoists,
The first double-acting hydraulic hoist 13 is divided into oil chambers 17 and 18 by a piston 16, and each oil chamber 17 and 18 is connected to an oil pipe 22 and 23 through an oil passage 20 and 21 in a piston rod 19.
It is communicated with.

The second double-acting hydraulic hoist 14 has a piston 24 and an oil chamber 25.
26, one oil chamber 25 communicates with an oil pipe 27, and the other oil chamber 26 communicates with the oil pressure 18 of the first double-acting hydraulic hoist 13 through an oil passage 29 in the piston rod 28 and an oil pipe 30. It is communicated.

The third double-acting hydraulic hoist 15 is also divided into oil chambers 32 and 33 by the piston 31, one oil chamber 32 is connected to the oil pipe 36 via an oil passage 35 in the piston rod 34, and the other oil chamber 33 is connected to the piston rod 34. The oil chamber 26 of the second double-acting hydraulic hoist 14 is connected to the oil chamber 26 of the second double-acting hydraulic hoist 14 via the oil passage 37 and oil pipe 38 in the rod 34.
is communicated with.

The oil pipes 22 and 23 are the main switching valves 3 in 4 directions and 3 positions.
The oil pipe 27 is connected to the hydraulic pump 40 and the tank 41 via the first electromagnetic switching valve 4.
The oil pipe 36 is connected to the oil pipe 22 so as to be connected to the oil pipe 22 in an excited state via a second electromagnetic switching valve 43, and the oil pipe 36 is connected to the oil pipe 27 in an excited state via a second electromagnetic switching valve 43.
, and thus each double-acting hydraulic hoist 13.1
4.15 connects each reduction hydraulic oil chamber 18.2633 to oil pipe 30.
38, the extension hydraulic oil chambers 17, 25,
32 is connected to the supply/discharge port of the main switching valve 39 via electromagnetic switching valves 42 and 43.

44 is a telescopic boom length detection device, in which a housing 45 is fixed to a non-extendable member such as the base tube 5, and a screw punch 46 is rotatably protruded from the housing 45 with one end protruding 47 out of the housing. A rotary reel 48 is fixed to the protrusion 47.

In the casing 45, limit switches 49 and 50 for operating the first and second electromagnetic switching valves 42 and 43 are fixed side by side along the screw punch 46 at appropriate intervals via a movable table 51. At the same time, an actuating piece 52 is screwed onto the screw punch 46 to turn on and off the limit switches 49 and 50, and as the screw punch 46 rotates, the actuating piece 52 is threaded to turn on and off the limit switches 49 and 50. It is designed to be operated.

The cam piece 53 is a cam piece fixed to the actuating piece 52, and the cam piece 53 maintains the electrical connection state of the limit switch 49 until the actuating piece 52 operates the limit switch 49 and then operates the limit switch 50. and
Reference numeral 54 denotes a receiving piece screwed onto the screw punch 46 in the same manner as the actuating piece 52, and a compression spring 55 is interposed between the actuating piece 52 and the screwing state of the actuating piece 52 to the bottom. It is pressed against one side of the screw thread of the screw punch 46 to regulate it.

In addition, 56 is a posture regulating rod for the actuating piece 52 and the receiving piece 54,
It is horizontally suspended in the housing 45 in parallel with the screw punch 46 and is engaged with notched portions (not shown) formed in the operating piece 52 and the receiving piece 54.

Reference numeral 57 denotes a winding device fixedly installed in parallel with the rotary reel 48, which rotates around the rotary reel 48 and closes the second electromagnetic switching valve 4.
The conductive wire 58 led out to the telescopic boom 4 is wound up by an internal mainspring spring (not shown).
It is rewound by the stretching operation of .

The limit switches 49 and 50 are moved to the right or left via the movable table 51 in conjunction with the switching operation of the main switching valve 39 when the telescopic boom 4 is extended or contracted. is being done.

That is, 59 is a hydraulic cylinder provided outside the casing 45, one chamber 61 partitioned by a piston 60 is communicated with the oil pipe 23, and a compression spring 63 in another chamber 62 constantly moves the piston 60 into the chamber 61. When the main switching valve 39 is in the telescopic boom extension operation position, the movable base 51 is inserted through the piston rod 64.
The push limit switches 49 and 50 are positioned to the right so that they contact the cloth-attached stopper 65.

Conversely, when the main switching valve 39 is switched to the telescopic boom retraction operation position, pressure oil is supplied to the oil chamber 61 via the oil pipe 23, and the limit switches 49 and 50 are moved to the movable base 51.
can be switched to a leftward position in which it abuts against the existing stopper 66.

As a result, the limit switches 49 and 50 of the telescopic boom length detection device 44 are activated by the limit switch 49 when the telescopic boom 4 is extended, when the first double action is performed, and when the first double action hydraulic hoist 13 is activated by the limit switch 49.
When the second double-acting hydraulic hoist 14 is at its maximum extension, the first electromagnetic switching valve 42 is switched and operated, and when the second double-acting hydraulic hoist 14 is at its maximum extension, the second electromagnetic switching valve 43 is switched and operated by the limit switch 50, and when the telescopic boom 4 is retracted, , the limit switch 50 switches the second electromagnetic switching valve 43 when the third double-acting hydraulic hoist 15 is at its minimum contraction, and the limit switch 49 switches the first electromagnetic switching valve in synchronization with the maximum contraction of the second double-acting hydraulic hoist 14. It operates to switch and operate the valve 42.

67 is a support device for the conductive wire 58 in the third double-acting hydraulic hoist 15, which has a support rod 68 erected at the outer end of the piston rod 34, and a pulley 69 at one end of the upper end. A horizontal rod 70 provided thereon is supported movably in the axial direction of the piston rod 34.

The other end of the horizontal rod γ0 is partially formed into a screw rod, and a fixing nut 71 is movably and fixedly screwed thereto, and the horizontal rod γ0 is always connected between the fixing nut 71 and the support rod 68. A compression spring 72 is interposed to bias the pulley 69 toward the cylinder tube, and a compression spring 72 is provided in the cylinder tube to abut against the horizontal rod 10 when the third double-acting hydraulic hoist 15 is contracted. A rod 73 is erected, and 1.
A little before the most contracted state, it came into contact with the horizontal rod 70 and the horizontal rod 1
0 is moved against the elastic force of compression spring γ2,
The conductive wire 58 suspended from the pulley 69 is operated to loosen it.

Further, the compression spring 12 is configured so that its elastic force is stronger than the restoring force of the mainspring spring installed in the winding device.

Therefore, by the contraction operation of the third double-acting hydraulic hoist 15, the tension of the conductive wire 58 is relaxed as described above, and the conductive wire 58 is thereby relaxed.
8 is wound up by a winding device 57, the screw punch 46 is rotated via a rotary reel 48, and the actuating piece 52 is moved to cut off the electrical connection state of the limit switch 51.

74 and 75 are switches provided in the electromagnetic circuits of the first electromagnetic switching valve 42 and the second electromagnetic switching valve 43, and by operating these switches 14 and 15, each double-acting hydraulic hoist 13, 14, 15 expansion/contraction states can be corrected.

Note that 16 is a power source.

Next, the present invention will be explained in detail.

As shown in the second diagram, each double-acting hydraulic hoist 13, 14, 1
5 is maximally contracted and the telescopic boom 4 is contracted, the main switching valve 39 is operated to the ■ position, and the pressure oil is transferred to the oil pipe 2.
2, the pressure oil is further supplied to the first electromagnetic switching valve 42 and the oil pipe 2.
2 and the piston rod 19 of the first double-acting hydraulic point 13
The oil is supplied to the oil chamber 13 through the internal oil M20.

Thus, the oil in the opposing oil chamber 18 flows through the oil passage 2 in the piston rod 19.
1 to the oil pipe 23, and the main switching valve 39 to the tank 41.
The first double-acting hydraulic hoist 13 alone can be extended to extend the first middle cylinder 10 with respect to the base cylinder 5.

On the other hand, as the first middle cylinder 10 moves, everything after the first middle cylinder 10 moves integrally, so the conductive wire 58 is pulled out by the above-mentioned amount of extension against the restoring force of the mainspring spring of the winding device 57. Rotating the rotary reel 48 and screwing the screw pestle 46
, the actuating piece 52 is screwed to the left as shown in the fourth diagram, and the limit switch 49 of the first electromagnetic switching valve 42 is approximately synchronized with the maximum extension of the first double-acting hydraulic hoist 13 to electrically connect it. Then, the first electromagnetic switching valve 42 is energized to bring the main switching 39 connection side of the oil pipe 22 and the oil pipe 27 into communication.

When the first electromagnetic switching valve 42 is switched, the pressure oil discharged from the outlet of the main switching valve 39 passes through the oil pipe 27 via the first electromagnetic switching valve 42 and is then transferred to the second double-acting hydraulic hoist 14. It is supplied only to the oil chamber 25.

The oil in the opposing oil chamber 26 passes through the oil passage 29 in the piston rod 28, the oil chamber 18 of the first double-acting hydraulic hoist 13, the oil passage 21 in the piston rod 19, and then via the oil pipe 23 and the main switching valve 39. The oil is drained into the tank 41, and only the second double-acting hydraulic hoist 14 extends to extend the second middle cylinder 11 with respect to the first middle cylinder 10.

At this time, similarly to the extension operation of the first middle cylinder 10 described above, the conductive wire 58 is further pulled out, and the actuating piece 52 is further moved to the left, so that it is approximately synchronized with the maximum extension of the second double-acting hydraulic hoist 14. The second electromagnetic switching valve 43 is energized by the limit switch 50, and the oil pipe 27 and the oil pipe 36 are brought into communication.

In this state, the cam piece 53 of the operating piece 52 remains in contact with the limit switch 49, so the first electromagnetic switching valve 42 maintains the oil pipe 22 and the oil pipe 27 in a communicating state.

In this state, the pressure oil in the oil pipe 22 is now supplied only to the oil chamber 32 of the third double-acting hydraulic hoist 15 through the oil pipes 27 and 36 and through the oil passage 35 in the piston rod 34.

As a result, the oil in the opposing oil chamber 33 is discharged to the tank 41 via the oil passage 37 in the piston rod 34, the oil chamber 26 of the second double-acting hydraulic hoist 14, the oil chamber 18 of the first double-acting hydraulic hoist 13, and the oil pipe 23. Then, the third double-acting hydraulic hoist 15 is extended, causing the inner cylinder 12 to extend with respect to the second middle cylinder 11, and the telescopic boom 4 is brought into a fully extended state.

Then, due to the extension of the third hydraulic hoist 15, the horizontal rod 70 and the contact rod 73 in the support device 67 for the conductive wire 58 are
The conductive wire 58 is further moved out in accordance with the movement of the horizontal rod 70 by moving the horizontal rod 70 somewhat to the left by the restoring action of the compression spring 72 accompanying the dissociation operation, and further expanding and contracting the conductive wire 58. The actuation piece 52 of the boom length detection device 44 is moved to the left.

When retracting the telescopic boom 4 in response to the above-mentioned extension operation, simply operate the main switching valve 39 to the ■ position in the above-mentioned maximum extension state, and the pressure oil discharged from the main switching valve 39 will flow through the oil pipe 23. Oil chamber 18 of each double-acting hydraulic cylinder
26, 33 and the oil chamber 61 in the hydraulic cylinder 59 of the telescopic boom length detection device 44.

As a result, the limit switches 49 and 50 of the telescopic boom length detection device 44 are moved to the left position where they contact the stopper 66 while remaining in contact with the cam piece 53 of the operating piece 52, and only the third double-acting hydraulic hoist 15 is moved. Since the oil chamber 33 is communicated with the tank 41 via the second electromagnetic switching valve 43, the first electromagnetic switching valve 42, and the oil pipe 22, it is possible to reduce the size of the telescopic boom 4 so that only the inner cylinder 12 is in the second It is made to slide and move relative to the cylinder 11 to reduce the size.

Then, by maximally contracting the third double-acting hydraulic hoist 15, the contact rod 73 in the support device 67 for the conductive wire 58 is moved to the horizontal rod 7.
0, the horizontal rod 70 is forcibly moved to the right against the restoring force of the compression spring 72, and the conductive wire 58 is loosened and wound up by the winding device 57.

Thus, the rotary reel 48 is rotated, the operating piece 52 is moved to the right, electrical contact with the limit switch 50 is cut off, and the second electromagnetic switching valve 43 is de-energized.

As a result, in synchronization with the complete contraction of the third double-acting hydraulic hoist 15, the second electromagnetic switching valve 43 is switched to a state in which the oil chamber 25 of the second double-acting hydraulic hoist 14 is communicated with the oil pipe 22, and then Then, only the second double-acting hydraulic hoist 14 operates to contract, causing the second middle cylinder 11 to contract into the first middle cylinder 10.

As the second double-acting hydraulic hoist 14 contracts, the conductive wire 58 is also wound up to rotate the rotary reel 48 and the screw punch 46.
The actuating piece 51 is moved to the right by , and in synchronization with the maximum contraction of the second double-acting hydraulic hoist 14 , the electrical contact of the limit switch 49 is cut off, and the excitation of the first electromagnetic switching valve 42 is released.

Then, the first electromagnetic switching valve 42 is switched, and pressure oil is supplied to the oil chamber 17 of the first double-acting hydraulic hoist 13, so that the first double-acting hydraulic hoist 13 is contracted and transferred to the base cylinder 5. In contrast, the first middle cylinder 10 is reduced in size.

At this time, the operating piece 52 moves further to the right away from the limit switch 49, and stops when the telescopic boom 4 is fully retracted to prepare for the next extension operation.

In addition, as mentioned above, the extension operation from the most contracted state or the contraction operation from the most extended state is forcibly controlled so that the cylinder always extends sequentially from the base position and contracts sequentially from the previous position. In addition, the telescopic boom 4 can be extended or retracted from a partially extended or retracted state, and can also be extended or retracted from a cylindrical body that is in the middle of being extended or retracted.

Therefore, cargo handling work is carried out by extending the telescopic boom 4 to an appropriate halfway state or fully extended state, and cargo handling work with the maximum allowable load for each boom length can be carried out with the maximum strength at each boom length. It is.

FIG. 5 shows an operating circuit diagram of each double-acting hydraulic hoist in another embodiment of the present invention. The hydraulic hoist 15 is connected to a hydraulic pump 40 and a tank 41 via completely independent first, second, and third switching valves 77, 78, and 79, respectively, and each double-acting hydraulic hoist 13 and
14 and 15 are individually telescopically operated by operating the manual switching operation devices 80, 81, and 82, and each part can be telescopically extended or retracted sequentially or simultaneously. This equipment forcibly controls the expansion and contraction order of each double-acting hydraulic hoist.

That is, by further adding electromagnetic switching operation devices 83 and 84 to the second and third switching valves 78 and 79, the first and second switching valves are operated in conjunction with the operation of the telescopic boom length detection device 44, just as in the first embodiment. The double-acting hydraulic hoist 13, the second double-acting hydraulic hoist 14, and the third double-acting hydraulic hoist 15 are extended in this order,
In addition, the data are sequentially reduced in the reverse order.

Note that 84, 85, and 86 are changeover switches provided in the electromagnetic circuit for selectively switching the electromagnetic switching devices 83, 84 of the second and third switching valves 78, 79 to manual switching devices 81, 82 as necessary. It is.

As described above, the present invention provides a telescoping boom in which boom tubes are sequentially inserted in a telescopic manner, and a sliding movement device is provided between each boom circumference, and the sliding movement device controls the operation of each sliding movement device. The telescopic boom is provided with a flexible member that is wound up by a take-up device provided at a suitable position on the telescopic boom and is rewound and retracted as the telescopic boom expands and contracts. A rotary reel is provided which is wound around the middle of the flexible member and rotated by unwinding and winding movement of the flexible member, and the control means of the sliding motion device is controlled in conjunction with the rotation of the rotary reel, and the telescopic boom is controlled. Since it is configured to be forced to extend in a predetermined order, the boom length can be varied by inserting and inserting the base cylinder, middle cylinder, and inner cylinder in sequence and sliding these cylinders relative to each other. By automatically and forcibly controlling the extension of the telescoping boom either sequentially or simultaneously, it is possible to carry out cargo handling operations while maintaining the cargo handling load at the maximum allowable load for each boom length. Since the sliding motion device between each cylinder is controlled by the winding and unwinding of the flexible member as it expands and contracts, it is possible to simultaneously detect the length of expansion and contraction of the telescopic boom and the position of the cylinders at each stage. It is.

Furthermore, in the present invention, the flexible member 58 is wound around the rotary reel 48, and this is used to control the control means, so that the rotation of the winding device for the flexible member can be directly controlled, unlike the conventional method. It has the following technical advantages compared to when it is used to control a control means.

That is, when the rotation of the winding device is used to directly control the control means, when the flexible member is wound around the drum in two or three layers, the winding of the flexible member per rotation of the drum is Since the amount of unwinding varies, a correction device is required to accurately measure the boom length, and if the flexible member is wound on the drum in an irregular manner, accurate measurement will be impossible. (Note that winding drums are generally prone to irregular winding if there is no irregular winding prevention device.

). Furthermore, if the flexible member is wound in only one layer in order to eliminate this drawback, a large drum will inevitably be required, which will impose disadvantageous design conditions in terms of cost and space. It could become a problem.

However, in the present invention, since the control means is controlled by a rotary reel in which the flexible member is wound only one layer (usually one to three times), the number of windings per turn of the rotary reel is The amount does not increase or decrease, and therefore no correction device is required.

In addition, since the amount of winding on a rotating reel is constant, accurate measurements can be expected without the risk of irregular winding, and there is no need for a winding prevention device or a large reel. It has the remarkable feature that it can be designed under advantageous conditions in terms of cost and space.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; Fig. 1 is a side view of a mobile cargo handling device equipped with the device of the present invention, Fig. 2 is a sectional view of a telescopic boom, and Fig. 3 is an operating circuit diagram of each sliding movement device. , FIG. 4 is an explanatory diagram of the telescopic boom length detection device, and FIG. 5 is an operating circuit diagram of each sliding motion device in another embodiment.

Claims (1)

[Claims] 1. In a telescopic boom formed by sequentially inserting boom tubes in a telescopic manner, a sliding movement device is provided between each boom section,
The sliding movement device is provided with a control means for controlling the operation of each sliding movement device, and the telescoping boom is wound up by a winding device provided at a suitable position of the telescoping boom and rewound as the telescoping boom expands and contracts. A rotary reel is provided, which is provided with a flexible member to be wound up, and is wound in the middle of the flexible member, and rotates as the flexible member is unwinded and retracted. 1. A telescoping boom for a cargo handling device, characterized in that the telescoping boom is configured to forcibly operate to extend the telescoping boom in a predetermined order by controlling a control means of a sliding motion device.