JPH101289A - Telescopic boom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a telescopic boom such that a middle boom can be supported more stably than conventional ones and that the allowable hanging load of the boom can be increased or time extended size of the boom can be made longer than that of conventionaI ones. SOLUTION: In a telescopic boom comprising at least three booms, i.e., a base end boom 1, a middle boom 2, and an end boom 3, at least either the side guide support 7 of an end-boom side guide mounted on the end of the middle boom 2 or the sheave support 5 of a wire rope sheave journalled to the end of the middle boom 2 is secured in place while being almost flush with or sunk from the outside surface of the middle boom 2, and the end of the base end boom 1 is elongated so that in the retracted state of the boom with the middle boom 2 retracted into the base end boom 1, at least either the side guide support 7 or the sheave support 5 fits into the first boom 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage telescopic boom comprising at least three stages of a base boom, an intermediate boom and a distal boom.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a multistage telescopic boom is composed of three stages, for example, a base boom a, an intermediate boom b, and a distal boom c. The telescopic operation of a built-in telescopic cylinder (not shown) allows the telescopic operation to be performed by the action of a wire stretched over each boom.

[0003] At the tip of the intermediate boom b,
A sheave d for stretching the above-described wire is provided, and a side guide e (see FIG. 10) for preventing the tip boom c from swaying when the tip boom c expands and contracts.

[0004]

However, in the above-mentioned conventional multistage telescopic boom, the sheave d and the side guide e are not provided.
Are provided by mounting members d1 and e1, and the mounting members d1 and e1 are provided so as to protrude from the outer surface of the distal end portion of the intermediate boom b (see FIG. 10 for mounting members of the side guide e). e1). For this reason, in the boom retracted state in which the intermediate boom b is retracted to the base boom a, the distal end portion of the intermediate boom b is set so that the projecting mounting members d1 and e1 do not interfere with the distal end portion of the base boom a. It was necessary to make the end boom a protrude from the tip of the end boom by a predetermined length.

Here, when the intermediate boom b is extended,
The base boom a supporting the intermediate boom b is preferably as long as possible to stably support the intermediate boom b. That is, if the support interval of the intermediate boom b with respect to the base end boom a is long, the stress acting on both the booms a and b is reduced, and the allowable load for suspending the boom can be increased. If the allowable stress acting on both the booms a and b is the same as in the prior art, the extension dimension of the boom can be made longer than in the prior art.

[0006]

According to a first aspect of the present invention, there is provided a multi-stage telescopic boom comprising at least three stages of a base end boom, an intermediate boom and a distal end boom. At least one of the side guide support of the side guide for the end boom attached to the sheave or the sheave support of the sheave for the wire rope pivotally supported at the tip of the intermediate boom from the outer surface of the intermediate boom and substantially one or the outer surface While fixed in the retracted state, in the boom storage state in which the intermediate boom is retracted in the base boom, so that at least one of the side guide support or sheave support fits in the base boom,
The distal end of the proximal boom is extended.

In the multistage telescopic boom according to a second aspect of the present invention, in the multistage telescopic boom according to the first aspect, the sheave support is fixed to a fixing member fixed from inside a side surface of the intermediate boom, and is fitted into the fixing member. And a mounting pin fixed and connected to the shaft of the sheave.

According to a third aspect of the present invention, there is provided the multi-stage telescopic boom according to the first aspect, wherein the side guide support is fixed to the intermediate boom from the inside of a side surface of the intermediate boom. The side guide is supported by the part.

A multi-stage telescopic boom according to claim 4 of the present invention is a multi-stage telescopic boom comprising at least three stages of a base end boom, an intermediate boom and a distal end boom, for a distal end boom attached to a distal end portion of the intermediate boom. The distal end of the base boom is expanded so that at least one of the side guide support of the side guide or the sheave support of the wire rope sheave pivotally supported by the distal end of the intermediate boom fits into the base boom. It was formed.

[0010]

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

FIG. 1 shows the configuration of a multistage telescopic boom according to the present invention.

This multi-stage telescopic boom is composed of a three-stage boom, a base end boom 1, an intermediate boom 2 and a distal end boom 3.

A sheave 4 is provided in the tip of the intermediate boom 2. The sheave 4 is for extending a wire, and the wire is used for extending and retracting the intermediate boom 2 and the distal end boom 3 along with the extension and contraction operation of the built-in extension cylinder.

As shown in FIG. 2, the sheave 4 is disposed at one end of the intermediate boom 2 inward on one side and along the one side via a sheave support 5 in the vicinity of the end of the intermediate boom 2.

The sheave support 5 comprises a fixing member 51 welded from the inside of the side surface of the intermediate boom 2 and a mounting pin 54 fitted and fixed to the fixing member 51.

The fixing member 51 is fixed in such a manner that its peripheral edge is in contact with the peripheral edge of the mounting hole 21 formed in the intermediate boom 2 from inside, and a fitting hole 52 formed in the center of the fixing member 51. The mounting pin 54 is fitted into the connector.

The mounting pin 54 has a flange 55 formed at one end thereof fitted in a recess 53 formed at the periphery of the fitting hole 52 of the fixing member 51. The upper end of the flange portion 55 is notched, and the mounting pin 54 is prevented from rotating with respect to the fixing member 51 by welding a stopper member 56 into the concave portion 53 corresponding to the notched portion. It is inserted in a state.

At one end of the outer surface of the mounting pin 54,
A counterbore 57 is formed, and a bolt 5 is inserted into the counterbore 57.
The head portion 8 is arranged, and the shaft portion 41 of the sheave 4 and the mounting pin 54 are connected by the bolt 58.

The sheave support 5 thus constructed
By supporting the sheave 4, the sheave support 5 can be arranged without protruding outward from the side surface of the intermediate boom 2.

Further, a sliding contact pad (side guide) is provided on a side surface of the intermediate boom 2 to prevent the tip boom 3 from laterally swaying during the extension / retraction operation of the tip boom 3 and to smoothly perform the extension / retraction operation. I have.

As shown in FIG. 3, the sliding contact pad 6 is provided via a pad support (side guide support) 7 provided in a mounting hole 22 formed on the side surface of the intermediate boom 2.

The pad support 7 has concave portions 71, 7 at both ends.
2 and a flange 73 is formed on the outer peripheral surface in the middle.

The size of the outer peripheral surface of the pad support 7 is substantially the same as the size of the mounting hole 22, and the length from the flange 73 to one end on the outer side of the boom is equal to the size of the mounting hole 22. The thickness of the provided intermediate boom 2 is substantially the same. Therefore, one end of the pad support 7 is moved from the inside of the intermediate boom 2 until the flange 73 abuts.
One end of the pad support 7 is fitted into the mounting hole 22, and the flange 73 and the intermediate boom 2 are fixed from inside by bolts 74, so that the pad support 7 protrudes outward from the side surface of the intermediate boom 2. It is arranged without letting it.

The sliding contact pad 6 is arranged in a concave portion 72 formed at the other end of the pad support 7, and the sliding contact pad 6 is provided with a concave portion 71 on one end side of the pad support 7.
And is supported by bolts 75 penetrating therethrough.

Reference numeral 11 in FIG. 1 designates a mounting member for attaching a sliding contact pad for preventing the intermediate boom 2 from swaying during the expansion and contraction operation of the intermediate boom 2 and smoothly performing the expansion and contraction operation. Reference numeral 12 denotes a support member provided on the bottom surface of the distal end portion in the base end boom 1 and supporting the intermediate boom 2 in the vertical direction. A support member 13 (see FIG. 4B) for supporting the upper surface of the intermediate boom 2 is provided on the upper surface of the middle part of the base boom 1.

As described above, since the sheave 4 and the sliding contact pad 6 are provided on the intermediate boom 2, the distal end portion of the intermediate boom 2 has nothing protruding outward from a side surface thereof. As a result, when storing the multistage telescopic boom, the entire distal end portion of the intermediate boom 2 can be stored in the base end boom 1 as shown in FIG.

Therefore, when comparing the conventional multi-stage telescopic boom (see FIG. 4A) having the same length at the time of storage with the multi-stage telescopic boom of the present invention (see FIG. 4B), The multi-stage telescopic boom can extend the total length of the base end boom 1 by an amount to accommodate the distal end of the intermediate boom 2, and the supporting members 12 and 13 support the vertical direction of the intermediate boom 2 by the lengthened portion. A long lap margin A between the end boom 1 and the intermediate boom 2 can be secured. That is, by securing the lap allowance A longer, when the intermediate boom 2 is extended from the base end boom 1, the intermediate boom 2 can be supported more stably than the conventional one, and the boom can be suspended. The allowable load can be increased.

In the case where the lap allowance A is the same as the conventional one, the extension of the boom can be made longer than the conventional one.

FIG. 5 shows the configuration of a multi-stage boom when the tip boom 3 is made of FRP. When the tip boom 3 is made of FRP, the sliding contact pad 6 described above is used.
Instead, the side roller 8 prevents the end boom 3 from laterally oscillating.

As shown in FIG. 6, the side roller 8 is disposed in a mounting hole 23 formed on the side surface of the intermediate boom 2 via a support member 81 and a bracket 82. And it is arrange | positioned in the state protruded outward.

Thus, the provision of the side rollers 8 makes it impossible to store the entire distal end of the intermediate boom 2 in the base end boom 1 as in the above-described multi-stage telescopic boom, but the sheave 4 is provided in the same manner as described above. Therefore, the distal end portion of the intermediate boom 2 can be stored in the base end boom 1 up to the portion where the sheave 4 is provided, and the same effect as described above can be exerted.

Further, when the tip boom 3 is made of FRP, the bottom surface of the tip boom 3 is supported by a support roller 83 instead of the pad. The support rollers 83 are provided in a pair at the front and rear of a bracket 84 which is swingably supported by a pivot pin 85 below the distal end of the intermediate boom 2.

FIGS. 7 and 8 show the construction of the multistage telescopic boom according to the fourth aspect.

This multi-stage telescopic boom can be used without using the sheave support 5 and the pad support 7 described above.
And a pad attached by the conventional attachment member 9,
Therefore, the mounting member 9 is mounted so as to protrude outward from the side surface of the tip of the intermediate boom 2. The distal end of the base boom 1 is formed so as to protrude so as not to interfere with the protruding mounting member 9, and the entire front end of the intermediate boom 2 is housed in the protruding portion 1a. With this, the same effect as described above can be obtained.

[0035]

As described above, according to the multistage telescopic boom according to the first aspect of the present invention, the base end boom is arranged so that at least one of the side guide support and the sheave support is accommodated in the base end boom. The extension of the tip of
The total length of the base boom can be lengthened, and a length of the wrap between the base boom supporting the vertical direction of the intermediate boom and the intermediate boom when the intermediate boom is extended can be secured by the lengthened portion. Therefore, by securing a longer lap allowance, when the intermediate boom is extended from the base end boom, the intermediate boom can be supported more stably than the conventional one, and the allowable load for hanging the boom is increased. Can be done. When the wrap margin is the same as the conventional one, the extension of the boom can be made longer than the conventional one.

According to the multistage telescopic boom according to the second aspect,
With a simple configuration, the sheave support can be provided on the intermediate boom so as not to protrude from the outer surface of the intermediate boom.

According to the multistage telescopic boom of the third aspect,
With a simple configuration, the side guide support can be provided on the intermediate boom so as not to protrude from the outer surface of the intermediate boom.

According to the multistage telescopic boom according to the fourth aspect,
With a simple configuration in which the distal end portion of the base end boom is simply bulged, the total length of the base end boom can be lengthened, and the lengthened length has the same effect as the multistage telescopic boom according to claim 1. be able to.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a multistage telescopic boom according to the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a sheave support.

FIG. 3 is a cross-sectional view illustrating a configuration of a pad support (side guide support).

FIG. 4 is a side view for comparing a conventional multistage telescopic boom with the multistage telescopic boom of the present invention.

FIG. 5 is a side view showing a configuration of a multi-stage telescopic boom in which a tip boom is formed of FRP.

FIG. 6 is a cross-sectional view showing a configuration of a side roller (side guide) of a multistage telescopic boom having a front end boom made of FRP.

FIG. 7 is a plan view showing a configuration of a multistage telescopic boom according to a fourth aspect of the present invention.

FIG. 8 is a side view showing a configuration of a multistage telescopic boom according to a fourth aspect of the present invention.

FIG. 9 is a side view showing a configuration of a conventional multistage telescopic boom.

FIG. 10 is a cross-sectional view showing a configuration of a mounting member for mounting a side guide in a conventional multistage telescopic boom.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base end boom 1a bulging portion 2 intermediate boom 3 distal boom 4 sheave 5 sheave support 51 fixing member 54 mounting pin 6 sliding pad (side guide) 7 pad support (side guide support)

Claims (4)

[Claims] 1. A multi-stage telescopic boom comprising at least three stages of a base boom, an intermediate boom and a distal boom, wherein a side guide support of a side guide for a distal boom attached to a distal end of the intermediate boom or an intermediate boom. At least one of the sheave supports of the wire rope sheave pivotally supported at the distal end is fixed in a state of being substantially flush with the outer surface of the intermediate boom or from the outer surface, and the intermediate boom is retracted into the base end boom. A multi-stage telescopic boom, wherein a distal end portion of the base end boom is extended such that at least one of the side guide support and the sheave support is accommodated in the base end boom in the retracted state of the boom. 2. The multi-stage telescopic boom according to claim 1, wherein the sheave support is fixed to a fixing member fixed from inside the side surface of the intermediate boom, and is fitted and fixed to the fixing member and connected to a shaft of the sheave. Multi-stage telescopic boom consisting of mounting pins. 3. The multi-stage telescopic boom according to claim 1, wherein the side guide support is fixed to the intermediate boom from inside the side surface of the intermediate boom, and the side guide is supported at an inner end thereof. boom. 4. A multi-stage telescopic boom comprising at least three stages of a base end boom, an intermediate boom and a distal end boom, wherein a side guide support of a side guide for a distal end boom attached to a distal end of the intermediate boom or an intermediate boom. As at least one of the sheave supports of the wire rope sheave pivotally supported at the distal end portion fits in the base end boom,
A multi-stage telescopic boom, wherein a distal end of the base end boom is formed to bulge.