JPS6225513Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention comprises a base end boom, a second stage boom that is extendable and retractable with respect to the base end boom, and a tip boom that is telescopically inserted into the second stage boom. The base end boom and the second stage boom are extended and contracted by a hydraulic cylinder interposed between them, while the second stage boom and the tip boom are bent into a U-shape from an intermediate portion thereof. Both ends of the wire ropes are fixed to appropriate positions on the proximal boom, and the intermediate portion is hooked to the proximal end of the distal boom via a distal sheave provided at the distal end of the second stage boom. a wire rope for extension, and both ends of the wire rope bent into a U-shape from the middle part thereof are respectively fixed to the distal end part of the base end boom, and the middle part is provided at the base end part of the second stage boom. The boom can be expanded and contracted in conjunction with the expansion and contraction movement of the hydraulic cylinder by a boom expansion and contraction wire rope device comprising a contraction wire rope that is hooked to the base end of the tip boom via a base end sheave. This relates to a telescoping boom.

Conventionally, in this type of telescoping boom, in order to balance the load in the width direction of the boom, two wire ropes for extension and two wire ropes for reduction are prepared, and these wire ropes are attached at the tips of each on both sides of the boom in the width direction. It was customary to install them separately between the boom and the proximal boom.

However, when two lengthening wire ropes and two contraction wire ropes are provided in this way, it is necessary to balance the tension between the left and right pair of wire ropes, and for this reason, each wire rope has a dedicated wire rope. Moreover, the tension adjustment mechanism must be frequently adjusted, resulting in a complicated structure, increased costs, and complicated handling, resulting in poor workability.

Against this background, one wire rope is bent into a U-shape from its middle part and both ends are fixed to the base boom, while the middle part is made into a U-shape and the base end of the tip boom is bent. The part located on one side of the intermediate part is used as one extension wire rope or reduction wire rope, and the part located on the other side is used as the other extension wire rope or reduction wire rope. Accordingly, it has been proposed to integrate a pair of wire ropes for extension or a pair of wire ropes for contraction into a single wire rope, thereby automatically adjusting the tension between the pair of wire ropes.

However, conventionally, as a means for hooking the U-shaped intermediate portion of the extension wire rope or contraction wire rope to the base end of the tip boom, a grooved half-moon plate was attached to the base end of the tip boom. Moreover, the central part of the wire rope was set horizontally across the center, and the middle part of the wire rope was routed through the groove of this half-moon-shaped plate, and a wire stopper was attached to the outside of the half-moon plate. The structure becomes complicated, and as a result, the manufacturing cost increases due to an increase in the number of assembly steps and the number of parts.

Furthermore, since a grooved half-moon plate was attached to the proximal end of the tip boom horizontally across the axis of the tip boom, the internal space of the tip boom was narrow. When used as a boom for an aerial work vehicle, the hydraulic hose or control cable is generally routed through the inside of the boom and into the work platform attached to the tip of the boom. There was also the problem that it was difficult to secure enough space inside for the hydraulic hoses or control cables.

In view of the above-mentioned problems with conventional telescoping booms, the present invention aims to reduce manufacturing costs by simplifying the boom structure and to create a telescoping boom that secures sufficient space inside the boom. In a telescoping boom that was designed to provide
A protruding wire rope hook is formed on the outer peripheral surface of the proximal end of the tip boom, and an extension wire rope and a contraction wire rope are bent in a U-shape relative to the wire rope hook. It is characterized in that the intermediate portion is hooked around the outer peripheral surface of the proximal end of the distal end boom.

Hereinafter, the telescopic boom of the present invention will be explained based on the embodiment shown in Figs. 1 to 5. Fig. 1 shows an aerial work vehicle Z equipped with the telescopic boom according to the embodiment of the present invention. has been done. This aerial work vehicle Z
, a telescoping boom W is pivotably mounted on a swivel base Y that is rotatably mounted on a vehicle X, and
A work platform V is attached to the tip of the telescoping boom W for placing a worker on the tower. This telescoping boom W
(hereinafter simply referred to as boom W) is raised and lowered by a hydraulic cylinder P for raising and lowering, and the work platform V is raised and lowered by a pair of hydraulic cylinders Q for horizontal holding provided at the base end and the tip of the boom W, Q keeps it horizontal at all times. Also, this aerial work vehicle Z
It is possible to perform various work operations from above the workbench V, that is, to raise and lower the boom W, to rotate the workbench, and to rotate the workbench.

The boom W includes a base end boom 1 having a rectangular cross section as shown in FIGS. 2 to 4, and the base end boom 1.
It has a second stage boom 2 having a rectangular cross section that is telescopically inserted within the second stage boom 2, and a tip boom 3 having a circular cross section that is telescopically inserted within the second stage boom 2. . This proximal boom 1 and 2
The stage boom 2 is connected to the base end 1a of the base end boom 1 and the second stage boom 2 with its tail part entered into the tip boom 3 as shown by the chain line in FIG.
It is made to expand and contract by a telescoping hydraulic cylinder R installed between the base end portions 2a of. On the other hand, the tip boom 3 is made to extend and contract in conjunction with the telescoping motion of the telescoping hydraulic cylinder R, that is, the telescoping motion of the second stage boom 2, by a boom telescoping wire rope device S to be described later. .

The tip boom 3 is constructed by attaching a proximal end fitting 5 made of an iron pipe to the proximal end of a tubular body 4 made of FRP, and attaching a distal fitting 6 that functions as a workbench support member to the distal end thereof. As shown in FIGS. 3 and 4, this base end metal fitting 5 has short tubes 7, 7 of appropriate diameters on the outer peripheral surface of its base end 5a, respectively.
In addition to integrally protruding in the horizontal direction,
A flat plate 8 with sliders 9, 9, . These short pipes 7, 7 are for hooking an extension wire rope 32 and a reduction wire rope 33 of a boom extension/retraction wire rope device S, which will be described later. These are called wire rope hooks 7,7.

The boom extension wire rope device S includes an extension wire rope 32 that acts on the second stage boom 2 to extend the tip boom 3, as shown in FIG.
and a reduction wire rope 33 that acts to reduce the tip boom 3. As shown in FIGS. 2 to 4, the elongating wire rope 32 has its central portion 32c bent in a U-shape, and its lower surface is attached to the proximal fitting 5 at a position closer to the proximal end than the wire rope hooking portions 7, 7. After passing it around from the 5c side, both the cable ends 32a and 32b are attached to the wire rope hooking part 7,
7 toward the tip 3b side of the tip boom 3, and then wrapped around the tip 2a of the second stage boom 2 through a pair of tip side sheaves 21, 21 provided on the inner surface of the tip 2a, and then folded back. after,
Pull it out again along the tip boom 3 to the base end 1a side of the base boom 1, and attach the cable end fittings 36 to the pair of hooks 34a and 34b provided on the base end 1a, respectively.
It is fixed via 36.

In addition, the reduction wire rope 33 is bent at its center portion 33c into a U-shape, and is passed around the proximal end fitting 5 from the upper surface 5b side at a position closer to the tip than the wire rope hooking portions 7, 7. Both cable ends 3
3a and 33b were pulled out along the wire rope hanging parts 7 and 7 toward the base end 2a of the second stage boom 2, and then attached to the base end 2a of the second stage boom 2. Drum-shaped proximal sheave 2
0 rope grooves 24, 24 and folded back, the rope is pulled out again along the tip boom 3 toward the tip 1b side of the base boom 1, and the rope end is attached to a pair of hooks 35a, 35b formed on the tip 1b. Metal fittings 37, 3
It is fixed via 7. The extension wire rope 32 and the reduction wire rope 33 are connected to the screw rods 38 and 38 of the cable end fittings 36 and 36, respectively.
nuts 48, 48 and cable end fittings 37,
The length of the rope can be adjusted by adjusting the amount of tightening of the nuts 49, 49 screwed onto the screw rods 39, 37.

On the other hand, a rotating platform Y is connected to the workbench V which is pivotally supported by the tip end 3b of the tip boom 3.
A hydraulic hose and a control cable (hereinafter referred to as a hydraulic hose, etc.) are arranged from the side.
That is, the hydraulic hoses 17, 17, . . . , etc. are installed laterally on the upper surface of the base boom 1 from the base end 1a side to the tip end 1b side as shown in FIGS. 3 to 5. The sheaves 30, 30, . through the base end 2a of the second stage boom 2
pulled out to the side. Furthermore, this hydraulic hose etc.
7, 17, ... are hose receiving grooves 25 of the rear end sheave 20 provided at the base end 2a of the second stage boom 2,
25, ... is turned around to the boom tip side, passes through the inside of the tip boom 3, and then the tip boom 3
It is connected to a horizontal holding hydraulic cylinder Q housed within the horizontal holding hydraulic cylinder Q or to a joint 45 provided inside the distal end portion 3a of the distal end boom 3. The hydraulic hoses 17, 17, . . . connected to the joint 45 are further drawn into the workbench V side via connection hoses 53, 53, . Also, this hydraulic hose etc. 17,1
7, . . . are appropriately bent and extended by the action of the proximal sheave 20 in conjunction with the extension and contraction operation of the boom W. In FIG. 4, reference numeral 28 is a nylon plummer for supporting the hydraulic hoses 17, 17, . . . and is fixed inside the tip boom 3.

In addition, the total length of the hydraulic hoses 17, 17, etc. changes due to elongation due to aging, but in that case, the folding sheave device 22 is changed as described later.
Hydraulic hoses etc. 17, 17,
It is now possible to adjust without moving... That is, the folding sheave device 2
2 is a bearing stand 56 that supports both ends of the shaft 50;
Through holes 57, 57 are formed in 56, and this through hole 5
7, 57, ... are the screw rods 39, 39 of the rope end fittings 37, 37 of the wire rope 33 for reduction.
It is fixed to the base end 2a of the second stage boom 2 by inserting it into the housing and tightening it with nuts 60, 60, and by screwing the nuts 60, 60, the folding sheave device 22 is fixed to the bearing stand 56, 5
6 and can be moved in the boom axis direction. Note that the hose length can be adjusted within a length range equivalent to twice the movable amount of the folding sheave device 22.

Next, to explain the effects of the present invention, the telescopic boom of the present invention bends the middle parts of the extension wire rope and the contraction wire rope into a U-shape, and bends the intermediate parts of the extension wire rope and the reduction wire rope to the outer peripheral surface of the proximal end of the tip boom. Since the protruding wire rope hanging part is fixed by looping around it, when a grooved half-moon plate for folding back the wire rope and a wire stopper are provided at the base end of the tip boom, as in conventional telescoping booms. Its structure is simpler than that, and it has the effect of reducing manufacturing costs.

Furthermore, since the wire rope hook is provided protrudingly on the outer circumferential surface of the tip boom, it is easier to attach the wire rope to the tip of the boom than when a grooved half-moon plate is installed across the inside of the tip boom as in the case of conventional telescoping booms. There is also the practical effect that a wider internal space of the boom can be secured, and that when a hydraulic hose or the like is passed through the tip of the boom, it is easier to attach it.

[Brief explanation of the drawing]

Figure 1 is an overall view of an aerial work vehicle equipped with a telescoping boom according to an embodiment of the present invention, Figure 2 is a side view of the telescoping boom shown in Figure 1, and Figure 3 is the telescopic boom shown in Figure 2. FIG. 4 is a cross-sectional view taken from FIG. 2, and FIG. 5 is a diagram showing the state of piping of hydraulic hoses for the telescoping boom. DESCRIPTION OF SYMBOLS 1... Proximal boom, 1a... Proximal end of the proximal boom, 1b... Tip end of the proximal boom, 2... Second stage boom, 2a... Proximal end of the second stage boom, 2b...
...Tip of second stage boom, 3...Tip boom, 3
a...Proximal end of the tip boom, 3c...Outer peripheral surface of the tip boom, 7...Wire rope hanging part, 20...
Proximal sheave, 21...Distal sheave, 32...
Wire rope for extension, 33...Wire rope for reduction, R...Hydraulic cylinder, S...Wire rope device for boom extension and contraction, W...Telescopic boom.

Claims (1)

[Scope of utility model registration request] A base end boom 1, a second stage boom 2 that is extendable and retractable with respect to the base end boom 1, and the second stage boom 2.
The base end boom 1 and the second stage boom 2 are extended and contracted by a hydraulic cylinder R interposed between them. Boom 2 and the tip boom 3
, both ends of a wire rope bent into a U-shape from its intermediate portion are fixed to appropriate positions on the proximal end boom 1, and the intermediate portion is provided at the distal end portion 2b of the second stage boom 2. , 21 to the proximal end of the proximal end boom 3, and both ends of the wire rope bent into a U-shape from the intermediate part thereof to the distal end of the proximal boom 1. 1b, and the intermediate portion thereof is provided at the base end portion 2a of the second stage boom 2.
A telescoping boom capable of being expanded and contracted in conjunction with the expansion and contraction movement of the hydraulic cylinder R by a boom expansion and contraction wire rope device S comprising a contraction wire rope 33 hooked to the base end 3a of the boom. , protruding wire rope hooks 7, 7 are formed by protruding laterally from both sides of the boom width direction on the outer peripheral surface 3c of the base end 3a of the tip boom 3, and are bent into a U-shape. The intermediate part of the extension wire rope 32 and the reduction wire rope 33 is connected to the outer circumferential surface 3 of the proximal end 3a of the tip boom 3.
A telescoping boom characterized in that it can be rotated along the line C, and its both sides are hooked to the wire rope hooks 7, 7, respectively.