JPH02209394A - Multistage boom supporting mechanism - Google Patents

Abstract

PURPOSE:To receive a load applied to a boom at the tip by a wire so as to absorb a bending force applied to each of multistage booms by drawing out the wire so far retracted simultaneously with the boom contracted, and installing a corrective mechanism for holding a drawing angle of the wire so as to be drawn at all times. CONSTITUTION:When each of booms 10, 11 is drawn out, each of connecting strips (wire) 22, 23 of the same length as that of each of these booms 10, 11 is also drawn out of control rods 18, 19, and they works so as to pull up a top part of the topmost boom 11. Accordingly, a tilt angle in an operating rod 17 of a lowermost boom 9 is changed by a corrective mechanism 20 whereby a tip of the boom 11 at the topmost stage is pulled up by these wires 22, 23 connected in order, so that each of these booms 9, 10 and 11 is not bent by the load and these multistage booms 9-11 can be always rectilinearly maintained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a crane for lifting heavy objects by moving a hook up and down, and for lifting personnel, materials, etc. by moving a lifting platform up and down above a vehicle body. Regarding telescopic multi-stage booms used in lifting equipment that can be lifted to high places, in particular, the load applied to the tip of the multi-stage boom is partially borne by a flexible connecting band. The present invention relates to a multi-stage boom support mechanism that can prevent bending.

[Conventional technology]

A mechanism is often used in which a crane is attached to the vehicle body of the trunk, and the crane is operated to lift heavy objects, thereby stacking and unloading the cargo.

In addition, for assembly, painting, and repairs at high places such as highways and building construction, aerial work vehicles that raise and lower lifting platforms are often used. Increasingly, work involves descending from high places.

These conventional cranes, aerial work vehicles, etc. often use multi-stage booms in which multiple booms with different external shapes are inserted telescopically so that they can extend and contract in the length direction. Met.

In this multi-stage boom, the total length is extremely reduced when the length is reduced, and the total length is increased when extended, and there is no limit to the total length like truck-mounted cranes or boom-type aerial work vehicles. One mechanism has the advantage of being able to shorten the overall length of the boom during movement, and has been widely used.

However, in the multi-stage boom mechanism, a plurality of booms having different external shapes are assembled in a telescopic pink shape, and the number of sliding parts increases. For this reason, there is a drawback that there is a lot of wobbling and the tip tends to swing up and down due to wind, load, etc. when extended for a long time. In order to lift heavy objects, the strength of each boom must be increased, which increases the weight of the entire boom. In addition, each boom is made of metal, but when a load is applied to the tip, the entire boom flexes and deforms into an arched shape. Sometimes it was not possible to slide smoothly.

[Problem that the invention seeks to solve]

In this way, while the overall length of conventional multi-stage booms can be shortened when they are scaled down, in order to withstand large loads, each boom must be made stronger and stronger, which increases weight. Therefore, they had contradictory drawbacks. In addition, when a load is applied, each boom bends, but the sliding points between each boom must be manufactured with high accuracy even in the bent state. It was required.

[Means for solving problems]

The present invention provides a multi-stage boom that is slidably inserted in the length direction of the multi-stage boom to form a telescopic pink shape, and an operating rod that is swingably fixed to the upper surface of the lower end of the lowest boom of the multi-stage boom. The lower end of the boom is connected to the lower end of the boom in each stage, and the lower end of the boom is pulled out from the upper end of the boom in the lower stage. The lower end of the connecting band is connected to the lower end of the first stage boom, is pulled out from the upper end of the second stage boom, is reversed at the upper end of the control rod of the second stage boom, and is connected to the first stage boom. A connecting band connected to the upper end, a connecting band for tension that connects the upper end of the operating rod attached to the lowest boom and the upper end of the control rod of that boom, and a connecting band that corresponds to the amount of expansion and contraction of the multi-stage boom. The present invention provides a multi-stage boom support mechanism characterized by comprising a correction mechanism for controlling the inclination angle of an operating rod.

[Effect]

In the present invention, a control rod is swingably connected to the upper surface of the tips of the booms other than the topmost boom among the multi-stage booms, and a pair of connecting bands are connected from the tips of each boom to the inside of each boom. Pull it out, flip both connecting bands over the top of the control rod,
One connecting band is connected to the upper end of the connecting rod in the previous stage, and the other connecting band is connected to the base of the connecting rod in the previous stage. The uppermost boom is connected to the tip of a connecting band pulled out from the tip of the second-tier control rod, and the assembly is such that the connecting band forms a triangular shape. A swingable operating rod is connected to the bottom of the lowest boom.
The control rod and operating rod of this lowest boom are connected by a tension wire. Further, the operating rod is configured so that its inclination angle can be corrected by a correction mechanism.

Due to this configuration, when each boom is pulled out, a connecting band having the same length as each boom is pulled out from the control rod, and acts to pull up the top of the uppermost boom. Therefore, by changing the inclination angle of the operating rod of the lowest stage boom, the tip of the highest stage boom can be pulled up by the sequentially connected connecting bands, which prevents each boom from being bent by the load and allows the multi-stage boom to keep the boom in a straight line at all times. Since the correction mechanism corrects the inclination angle of the operating rod according to the amount of expansion and contraction of the multi-stage boom, the inclination angle of the connecting band that holds the uppermost boom is always maintained to be an isosceles triangle. For this reason,
Deflection of the upper stage of the multi-stage boom can be suppressed.

In other words, since the multi-stage boom is pulled by the connecting band in the opposite direction to the direction in which it is bent, it is held in the opposite direction to the direction in which the load is normally applied, and the stress applied to the multi-stage boom can be reduced.

For this reason, the multi-stage boom does not bend under the load (the multiple booms are always arranged in a straight line, so sliding is smooth, and the strength of each boom can be reduced compared to before, so the entire multi-stage boom The weight of can be reduced.

〔Example〕

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

In this embodiment, an example in which the present invention is applied to a crane-equipped working vehicle equipped with a crane mechanism will be explained.

A cabin 2 for a driver and the like to board is provided at the front of a vehicle body 1 housing an engine and the like, and a front wheel 3 and a rear wheel 4 are pivotally supported at the front and rear portions of the vehicle body 1. Outriggers 5 for fixing the vehicle body 1 in a fixed position are protruded from the front, rear, left and right sides of the vehicle body 1. A swivel base 6 is attached to the rear portion of the upper surface of the vehicle body 1 so as to be horizontally rotatable, and a holder 7 is mounted and fixed on the upper part of the swivel base 6. A lower boom 9 is swingably connected to the upper part of the holding body 7 by a pin 8, and a middle boom 10 is slidably inserted into the upper end opening of the lower boom 9.
A tip boom 11 is slidably inserted into the upper end opening of 0. These lower boom 9, middle boom 10, and front boom 11 form a boom mechanism that can extend and contract in its length direction.

A hydraulic cylinder 12 is interposed between the holder 7 and the lower boom 9 to control the elevation angle thereof.

Further, a head 13 is attached to the tip of the tip boom 11, and a hanging wire 14 is hung downward from the head 13.
A hook body 15 and a flap 16 are suspended from the lower part. An operating rod 17 is swingably provided on the upper surface of the lower part of the lower boom 9, and a correction mechanism 20 consisting of four hydraulic cylinders is connected to the operating rod 17. The swing angle is controlled.

A control rod 18 is slidably provided on the upper surface of the tip of the lower boom 9, and a control rod 19 is also provided on the upper surface of the tip of the middle boom 10 so as to be swingable. A tension wire 21 is stretched between the upper end of the operating rod 17 and the upper end of the control rod 18. A wire 22 serving as a connecting band is connected to the upper end of the control rod 19.
The wire 22 is inverted downward at the upper part of the control rod 18 and drawn into the interior through the opening at the tip of the lower boom 9, and the other end of the wire 22 is connected to the lower end of the middle boom 10. Further, a wire 23 serving as a connecting band is connected to the upper surface of the tip of the front boom 11, and this wire 23 is reversed at the top of the control rod 19, and is drawn inside from the upper end opening of the middle boom 10, and the wire 23 is The other end is connected to the lower end of the tip boom 11.

Next, FIG. 2 explains in detail the internal structure of the telescopic boom.

The inside of the middle boom 10 is hollow, and the middle boom 1
A hydraulic cylinder 25 is provided inside the 0 along its length. The cylinder iron 26 of this hydraulic cylinder 25 is directed toward the lower boom 9, and the tip of the cylinder iron 26 is connected to the lower part of the lower game 9. A tuning wire 3 is attached to the lower end of the tip boom 11.
8 are connected, and this wire 38 is inverted at the lower end of the middle boom 10, and the other end is connected to the upper end of the lower boom 9. Further, a tuning wire 39 is connected to the lower end of the front boom 11, and this wire 39 is inverted at the upper end of the middle boom 1o, and the other end is connected to the upper end of the lower boom 9. By this wire 38.39 3
The main booms 9, 10, and 11 are synchronized, and at the speed at which the middle boom 10 slides more than the lower boom 9, the front boom 11 will slide more than the middle boom 10.

Further, a guide body 27 having a slightly U-shape is fixed to the center of the upper surface of the lower boom 9.
A slider 28 is inserted into the internal space of the lower pool 9, and the slider 28 is guided so as to be movable in the length direction of the lower pool 9. Connecting rods 29 are fixed to the left and right sides of the lower pool 9, and hydraulic cylinders 30 and 31 are connected to the connecting rods 29, respectively, so as to be vertically parallel to each other. The cylinder rods of these hydraulic cylinders 30.31 are each connected to the actuating rod 17 at a distance, and are arranged in a slightly V-shaped configuration.

Next, FIG. 3 shows the vicinity of this correction mechanism 20 in an enlarged manner.

A slider 28 is inserted into the guide body 27, and the axis of the slider 28 is oriented approximately perpendicular to the axis of the lower boom 9, and the slider 28 itself can be moved in the length direction of the lower boom 9. It looks like this. and,
Connecting rods 29.32 are fixed to the left and right sides of the slider 28, respectively, and a hydraulic cylinder 30.3 is attached to the connecting rod 29.
1 is connected to the connecting rod 32, and a hydraulic cylinder 33 is connected to the connecting rod 32.
．． 34 are connected to each other. The cylinder rods of the hydraulic cylinders 31 and 34 are connected to a swing shaft located at the bottom of the operating rod 17. Moreover, the hydraulic cylinder 30.
The cylinder rods 33 are respectively connected to both sides of the center of the operating rod 17, and are connected to hydraulic cylinders 30 and 31.
and hydraulic cylinders 33 and 34, respectively, so that they are arranged in a slightly V-shape.

Next, FIG. 4 shows the control rod 1 at the tip of the lower boom 9.
8 will be explained in detail.

A control rod 18 is swingably connected to the upper surface of the upper end of the lower boom 9 by a pin 35, a pulley 36 is pivotally supported at the upper end of the control rod 18, and a pulley 37 is supported at the bottom of the control rod 18. is pivoted.

Then, the wire 22 is reversed by a pulley 36 and directed downward, and further guided into the inside of the lower boom 9 from the tip opening by the pulley 37, and the other end of the wire 22 is connected to the lower end of the middle boom 10 inside the lower boom 9. is connected to.

Next, FIG. 5 shows a hydraulic piping diagram in this embodiment, and only the mechanism of the telescopic boom is explained in this diagram.

The suction side of a hydraulic pump 40 driven by an engine 41 is connected to an oil tank 42, and the discharge side of the pump 40 is connected to a switching valve 43. Further, the discharge side of the switching valve 43 is connected to the oil tank 42 . and,
The output of the switching valve 43 is connected to the boom extension/retraction hydraulic cylinder 25, and correction hydraulic cylinders 30, 31, 33, 34 are connected in parallel to the discharge side of the hydraulic cylinder 25. Also, hydraulic cylinder 30.31.33
．． The discharge sides of 34 are grouped in parallel, and the switching valve 43
It is connected to the.

Next, the operation of this embodiment will be explained.

First, the engine 41 is operated and the hydraulic pump 40 is operated. Then, the pressure oil stored in the oil tank 42 is supplied to the switching valve 43. Here, when the switching valve 43 is switched in the positive direction, the pressure oil is transmitted to the hydraulic cylinder 25, and the hydraulic cylinder 25 is extended. At the same time, the pressure oil discharged from the hydraulic cylinder 25 is transferred to each hydraulic cylinder 30.
31.33.34 and these hydraulic cylinders 3
0.31.33.34 will also be expanded at the same time.

First, the extension of the multi-stage boom will be explained. As the hydraulic cylinder 25 extends, the cylinder rod 26 is pushed out, and the middle boom 10 is pushed out from the lower pool 9. As the middle boom 10 is pushed out from the lower boom 9, the tuning wire 38.39 is also moved at the tip of the middle boom 10, so the front boom 11 connected to the wire 38.39 also moves at the tip of the middle boom 10. It will be pushed out from the tip. Therefore, by the operation of the hydraulic cylinder 25, the middle poop 10 and the front boom 11 are pushed out from the lower poop 9 in synchronized amounts. At the same time as this operation, middle boom 1
0 is pushed out from the lower boom 9, the wire 22 is pulled out from the opening at the tip of the lower boom 9, and the wire 22 is let out through the control rod 18 so as to be parallel to the middle boom 10. Similarly, when the front boom 11 is pushed out from the middle pool 10, the wire 23 connected to the front boom 11 is pulled out via the operating rod 19 and is let out in a triangular shape.

In addition, since the tension wire 21 stretched between the operating rod 17 and the control rod 18 is always pulled, the tension wire 21 and the wires 22 and 23 are always in a tension state, and the tip of the front boom 11 is thereby is always pulled up in the opposite direction to the downward load. As mentioned above, in synchronization with the operation of the hydraulic cylinder 25, the hydraulic cylinders 30.31.33.34 also extend at the same time. Therefore, as the hydraulic cylinders 30.31, 33.34 extend, the connecting rod 29.32 is pushed out in the opposite direction to the operating rod 17, and the slider 28 is moved while sliding on the surface of the lower boom 9. I will let you do it. and hydraulic cylinders 30, 31 and 33.
．． Since the shape of the figure 7 formed by the combination of 34 has an acute angle, the operating rod 17 is lifted in a direction perpendicular to the axis of the lower poom 9, and acts to constantly pull up the tension wire 21. For this reason, the control rods 18 and 19, which are connected to the pull wire 21, are connected to the actuating rod 1.
The wire 23 is raised in synchronization with the inclination angle of the intermediate pool 10 while keeping the wire 22 parallel to the axis of the intermediate pool 10
is corrected so that the triangle formed by the tip pool 11 and the control rod 19 is always maintained in the shape of an isosceles triangle.

In this way a multi-stage boom and multiple wires 21.22
．． 23 operate in conjunction with each other, and the operation situation will be explained with reference to FIGS. 6 and 7.

In FIG. 6, the multi-stage boom is shown in the shortest contracted state, and in this case, the operating rod 17 and the control rods 18 and 19 are tilted to the left in the figure, respectively.
The front boom 11 is suspended by a wire 23. When the hydraulic cylinder 25 is actuated, the middle boom 10 and the front boom 11 are pulled out from the lower boom 9 and moved in the direction A in the figure, as described above. Since the amount of movement of the middle pool 10 and the front boom 11 is the same, the amount by which the wires 22 and 23 are pulled out is also the same. Then, middle boom 10. The front boom 11 is the lower boom 9
As the operating rod 17 is pulled out further, the adjustment mechanism 20
The movement in the B direction is controlled by the control rods 18 and 19 by the pull wire 21.
The control rods 18 and 19 are raised in the directions of arrows C and D, respectively.

FIG. 7 shows a state in which the middle boom 10 and the front boom 11 have been pulled out to a certain extent through these steps, and the operating rod 17 has been raised. In this state, the corrected angle of the operating rod 17 causes the control rod 19 to move. A correction is given in accordance with the amount of extension of the front boom 11, and its inclination angle is raised. For this reason, the angle α formed by the wire 23 and the control rod 19 and the angle α formed by the front boom 11 and the control rod 19 are corrected so that they are always equal.

In this way, since the load applied to the tip of the front boom 11 is always pulled up by the wires 23, 22 and the tension wire 21, the bending moment for the front boom 21 and the middle boom 10 is absorbed, and the load applied to the front boom 11 and the middle boom 10 is absorbed. Corrected so that it does not bend.

For this reason, the front boom 11 and the middle boom 10 always maintain a linear shape, and the extension/retraction motion with respect to the lower boom 9 becomes extremely smooth.

Moreover, FIG. 8 shows an example in which the present invention is applied to an aerial work vehicle used for lifting personnel and materials to a high place.

In this embodiment, a front wheel 52 and a rear wheel 53 are pivotally supported on the front, rear, left and right sides of a vehicle body 51, and the vehicle body 1 is configured to be able to move freely. It is rotatably mounted.

A pair of semi-triangular shaft support pieces 55 are fixed to the upper surface of the work body 54 at a distance, and the lower end of a lower boom 56 having a square cross section is inserted between the shaft support pieces 55. The lower boom 56 is pivotally supported by a bin 57 so as to be able to swing up and down. A middle boom 58 is inserted through the opening at the tip of the lower boom 56, and a front boom 59 is inserted through the opening at the tip of the middle boom 58. These lower pools 5
6. A multi-stage boom is formed by a middle boom 58 and a front boom 59.

A packet 60 for carrying people, materials, etc. is attached to the tip of the tip pool 59. Note that a hydraulic cylinder 61 for elevation is interposed between the work body 54 and the lower boom 56.

A working rod 62 is connected to the upper surface of the lower part of the lower boom 56, and a correction mechanism 63 for correcting this angle is connected to the working rod 62. In addition, control rods 64 are provided on the upper surface of the tip of the lower boom 56 and on the upper surface of the tip of the middle boom 5, respectively.
．． 65 is connected. A tension wire 66 is installed between the working rod 62 and the control rod 64.
A wire 67 is connected to the upper end of the middle boom 5, and this wire 67 is reversed by the control rod 64 and inserted through the upper end opening of the lower boom 56, and the other end is connected to the lower end of the middle boom 5. . Furthermore, a wire 68 is connected to the upper end of the tip poom 56 , and this wire 68 is reversed at the upper end of the control rod 65 and enters the inside of the middle boom 58 through the opening at the tip of the middle boom 58 . The other end is connected to the lower end of the tip boom 59.

In the operation of this aerial work vehicle, the middle pool 58
, at the same time as the tip poom 59 expands and contracts, the wire 66.67
．． 68 are each pulled synchronously, and the load applied to the tip of the tip pool 58 is applied to these wires 66, 67 .
68 is lifted to prevent each boom 56, 58, 59 from flexing.

〔effect〕

Since the present invention is constructed as described above, in a telescopic multi-stage boom, the wire that has been drawn in is pulled out at the same time as the boom expands and contracts, and the wire is held at a constant pulling angle so that the boom at the tip of the boom is pulled out. Since the wire can bear the applied load, it can absorb the bending force applied to each boom of the multi-stage boom and prevent the boom from deflecting.

Therefore, the axis of each boom in the multi-stage boom is always maintained in a straight line, and the sliding movement between the booms is maintained extremely smoothly.

Furthermore, since each wire can bear part of the load, the strength of the multi-stage boom can be reduced and the overall weight can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a perspective view illustrating an embodiment of the present invention attached to a vehicle with a crane, Fig. 2 is a sectional view showing the internal structure of the same multi-stage boom, and Fig. 3 is an enlarged perspective view showing the vicinity of the correction mechanism. , FIG. 4 is an enlarged perspective view showing the vicinity of the control rod, FIG. 5 is a piping diagram showing the hydraulic system in this embodiment, and FIG. 6 is an enlarged perspective view of the multi-stage boom in order to explain the present invention in detail. Explanatory diagram, FIG. 7 is an explanatory diagram showing the operation when the multi-stage boom is extended among the operations of the present invention, and FIG.
The figure is a side view showing another embodiment of the present invention. 9... Lower boom, 10... Middle boom, 11... Front boom, 17... Operating rod, 18.19... Control rod,
20... Correction mechanism, 21... Pull wire, 2
2.23... Wire as a connecting band Patent applicant: Hikoma Seisakusho Co., Ltd. Representative Patent attorney: Tsuneaki Hibi Diagram

Claims (1)

[Claims] A multi-stage boom that is slidably inserted in the length direction of the multi-stage boom to form a telescopic shape, an operating rod that is swingably fixed to the upper surface of the lower end of the lowest boom of the multi-stage boom, and a connecting band whose lower end is connected to the lower end of the boom, pulled out from the upper end of the boom in the lower stage, reversed at the upper end of the control rod of the boom in the lower stage, and connected to the upper end of the control rod of the boom; Its lower end is connected to the lower end of the first stage boom, and it is pulled out from the upper end of the second stage boom,
A connecting band that is inverted at the upper end of the control rod of the second stage boom and connected to the upper end of the first stage boom, and the upper end of the operating rod attached to the lowest stage boom and the upper end of the control rod of that boom. 1. A multi-stage boom support mechanism comprising: a tension connecting band connecting between the booms; and a correction mechanism that controls the inclination angle of an operating rod in accordance with the amount of expansion and contraction of the multi-stage boom.