JP2002167199A - Insulating boom head structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly connect a boom head to the tip of an insulating boom. SOLUTION: A hollow cylindrical outer collar 31 is stuck and connected to the tip part of a tip boom 5c made of an insulating material, and a hollow cylindrical inner collar 32 is inserted into the outer collar 31. In the boom head 5d inserted into the hollow space of the tip boom 5c, a bolt insertion hole 24 is formed in the position facing the inner collar 32, and a bolt 34 is inserted into the inner collar 32 from the outside face side via a washer 33. A bolt thread part 34a is screwed to a nut 35 arranged inside the boom head, and consequently, the inner collar 32 and the boom head 5d are fastened and clamped by means of the bolt and the nut via the washer 33. In this case, the outside diameter of the washer 33 is set to be larger than that of the inner collar 32, and the outer collar 31 is clamped between the washer 33 and the boom head 5d. The length of the inner collar 32 is set to be slightly longer than that of the outer collar 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating boom having at least a distal end formed from an insulating material and hollow, such as a boom of an aerial work vehicle for electric work, and a distal end side of the insulating part in a hollow space. More particularly, the present invention relates to an insulating boom head structure characterized by a structure for fixing the boom head to the tip of the insulating boom.

[0002]

2. Description of the Related Art Generally, an aerial work vehicle is configured such that a boom is mounted on a swivel provided horizontally rotatable above a vehicle so as to be able to move up and down, and a worktable is mounted at a tip of the boom. Well known to In addition, a boom is generally constructed by telescopically assembling a plurality of boom members in a nested manner. In such an aerial work vehicle, the workbench is moved to a desired height by raising and lowering and extending and retracting the boom in a state where the worker is on the workbench. Is performed. Such a work at a high place includes a wiring work in a live state, and in such a case, a part of the boom may be made of an insulating material in order to prevent an electric shock of an operator. Specifically, of the boom members assembled in a nested manner, the most distal boom member is made of an insulating material having a predetermined strength such as FRP or the like.

However, it is difficult to directly attach a worktable to the tip of such an FRP boom.
A metal boom head is attached to the tip of an RP boom, and a work table can be attached to the boom head. For this reason, it is necessary to firmly connect and fix a metal boom head to the tip of the FRP boom.

[0004]

However, when an FRP boom and a metal boom head are fastened and connected by bolts and nuts, creep deformation occurs when the FRP material receives bolt / nut fastening force for a long time. As a result, there is a problem that the bolt / nut fastening force is reduced and the bolt may be loosened.

[0005] For this reason, there is also a method in which a cylindrical metal collar member is penetrated and inserted into an FRP boom and joined, and this metal collar member and a metal boom head are fastened and joined by bolts and nuts. It has been used conventionally. However, in the case of such a coupling structure, an external force (moment) acting on the boom head from the workbench side is used.
The boom head is deformed by this, and this deforming force acts directly on the FRP boom via the metal collar member, causing FRP delamination at the joint between the metal collar member and the FRP boom, and noise caused by stick-slip. It has been found that there is a problem that this may occur.

The present invention has been made in view of such a problem.
An object of the present invention is to provide an insulating boom head structure in which a boom head can be firmly connected to the tip of an insulating boom, and the bolt fastening force in this connection does not loosen.

[0007]

In order to achieve the above object, an insulating boom head structure according to the present invention comprises an insulating boom having at least a tip portion formed of an insulating material and having a hollow portion, and a tip portion provided in the hollow space. And a boom head inserted and attached from the side. A boom through-hole extending in a direction perpendicular to the axial direction and penetrating into the hollow space from the outer surface side is formed at the tip of the insulating boom, and a hollow cylindrical outer collar member is inserted into the boom through-hole. The hollow cylindrical inner collar member is adhesively bonded and inserted into the outer collar member. Then, a bolt insertion hole is formed at a position facing the inner collar member in the boom head inserted into the hollow space of the insulating boom, and the bolt member is inserted into the inner collar member with the washer member from the outer surface side, and the bolt is inserted. Insert the tip screw part of the member into the bolt insertion hole and screw it with the nut member arranged inside the boom head,
The inner collar member and the boom head are fastened and clamped by a bolt member and a nut member via a washer member. Further, at this time, the outer diameter of the washer member is made larger than the outer diameter of the inner collar member, and the length of the inner collar member is set slightly larger than the length of the outer collar member. The members are held.

When the insulating boom head structure having such a structure is used, the bolt fastening force acts only on the inner collar member and the boom head member, and does not act on the boom tip made of an insulating material. There is no problem that the material receives the fastening force for a long period of time and undergoes creep deformation to cause bolt loosening. Also, since the outer collar member adhesively bonded to the end of the boom made of an insulating material is inserted into the inner collar member, even if the boom head is deformed by an external force from the workbench, the outer collar member has a deformation force. Does not work, and there is no problem of FRP delamination at the joint between the collar member and the boom head and generation of abnormal noise due to stick-slip as in the related art.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an aerial work vehicle 1 using the insulating boom head structure according to the present invention. The aerial work vehicle 1 can travel with front and rear wheels 3a and 3b, and is configured based on a truck vehicle having a driving cabin 2a at a front portion. A swivel 4 that is driven by a swivel motor (hydraulic motor) (not shown) so as to be able to swivel horizontally is disposed on the body 2 of the truck vehicle. A base end is pivotally connected to the swivel base 4 and a boom 5 is attached thereto. The boom 5 is configured to be raised and lowered by a lifting cylinder 6. The boom 5 is configured such that a base end boom 5a, an intermediate boom 5b, and a distal end boom 5c are nestedly combined and can be extended and contracted by a built-in extension cylinder 7.

The tip boom 5c has a boom head 5d at the tip.
And a support member 8 pivotally connected to the boom head 5d.
Are mounted to be able to swing up and down. The support member 8 has a vertical post (not shown),
The swinging control of the support member 8 is performed by a leveling cylinder (not shown) disposed between the support member 8 and the support member 8, and the vertical post portion always extends vertically regardless of the ups and downs of the boom 5. The swinging of the support member 8 is controlled so as to be positioned.
As described above, the work table 9 is attached to the vertical post portion which is always held vertically so as to be able to freely turn horizontally (to swing freely), and the work table 9 is always held horizontally irrespective of the ups and downs of the boom 5.

A lifting device 10 is provided at the upper end of the support member 8. Further, outriggers 11 which can be extended and contracted downward are provided at four front, rear, left and right sides of the vehicle body 2 so that the outriggers 11 can be protruded downward as shown to lift and support the vehicle body 2 when working in high places. Has become.

In the aerial work vehicle 1 having the above-described structure, the insulating boom head structure according to the present invention is applied to the tip boom 5c, which will be described with reference to FIGS. The tip boom 5c is made of FRP having electrical insulation.
(Fiber Reignforced Plastic) It is formed in a hollow rectangular column shape from a material, and a metal boom head 5d is connected and attached to the tip of the tip boom 5c.

The boom head 5d is composed of an insertion portion 21 inserted into the hollow space of the tip boom 5d and a head portion 22, and a tip portion of the head portion 22 is bifurcated to form a support portion 23. . The support portion 23 is formed with a support hole 23a penetrating left and right.
The support member 8 is attached to be able to swing up and down by a pivot pin inserted into the support member 8. The insertion portion 21 is formed in a hollow shape, and has four bolt insertion holes 2 on the left and right side surfaces, respectively.
4 is formed penetrating into the hollow space. Further, a nut 35 is attached to the inner surface of the hollow space of the insertion portion 21 by welding or the like corresponding to each bolt insertion hole 24.

The end boom 5c has four boom through-holes 26 formed in the inner hollow space 25 at four locations on the left and right side surfaces on the tip side, respectively.
A hollow cylindrical outer collar 31 is inserted therein. An adhesive is applied to the outer peripheral surface 31a of the outer collar 31 and is inserted into the boom through-hole 26. The outer collar 31 is firmly adhered and fixed to the distal end boom 5c while being inserted into the boom through-hole 26. .

To fix the boom head 5d to the tip boom 5c, first, the insertion portion 21 of the boom head 5d is inserted into the hollow space 25 from the tip end of the tip boom 5c. For this reason, the hollow space 25 of the distal end boom 5C is formed in a rectangular shape, and the insertion portion 21 is formed in a quadrangular prism shape having a dimension that allows it to be inserted into the rectangular hollow space 25 smoothly and without play. Also, the boom head 5d is located in the hollow space 25.
When completely inserted into the boom, the bolt insertion hole 24 faces the outer collar 31 inserted and fixed in the boom through hole 26.

Next, a hollow cylindrical inner collar 32 is inserted into each outer collar 31. The outer diameter of the inner collar 32 is set slightly smaller than the inner diameter of the outer collar 31, and the inner collar 32 is loosely inserted into the outer collar 31. Therefore, an extremely narrow gap is formed between the inner peripheral surface 31b of the outer collar 31 and the outer peripheral surface 32a of the inner collar 32, and the inner collar 32 is slidable in the axial direction and relatively rotatable with respect to the outer collar 31. is there.

Thereafter, the bolt 34 is inserted into the inner collar 32 with the disk-shaped washer 33 interposed therebetween. At this time, the bolt 34 has such a length that the tip screw portion 34a passes through the inner collar 32, passes through the bolt insertion hole 24 formed in the insertion portion 21 of the boom head 5d, and projects into the hollow space in the insertion portion 21. Have. For this reason, the threaded end 34 a of the bolt 34 is screwed with the nut 35 fixed on the inner surface side of the bolt insertion hole 24, and fastening by the bolt 34 and the nut 35 is possible. In this manner, when the bolt 34 is screwed into the nut 35 and tightened, the washer 33, the inner collar 32 and the insertion portion 21 are fixed to the bolt 34 and the nut 35.
And can be clamped.

If the bolt 34 is securely fastened as described above, the tip boom 5c made of an insulating material and the boom head 5d made of a metal material can be connected. At this time,
The outer diameter of the washer 33 is larger than the outer diameter of the inner collar 32,
The outer collar 31 is sandwiched between the washer 33 and the insertion portion 21 (tip boom 5d) so that the outer collar 31 does not drop even if the adhesive of the outer collar 31 is peeled off.
However, the length (width) dimension of the outer collar 31 is set slightly smaller than the length (width) dimension of the inner collar 32, and the outer collar 31 is sandwiched between the washer 33 and the insertion portion 21 without play. However, it does not receive the fastening force of the bolt and nut.

When the boom head 5d is connected to the tip of the tip boom 5c as described above, the bolt fastening force acts only on the inner collar 32 and the insertion portion 21 of the boom head 5d, and the tip boom 5c ( Or outside color 3
Since it does not act on 1), there is no problem that the insulating material receives the fastening force for a long period of time and undergoes creep deformation to cause bolt loosening as in the conventional case. In addition, as described above, the outer collar 31 is attached to the tip boom 5c.
It is adhered to and firmly joined to this outer collar 3.
1 is held between the washer 33 and the insertion portion 21 without backlash (and without receiving the fastening force of the bolts and nuts).
d does not rattle.

Since the outer collar 31 is inserted into the inner collar 32 and is relatively rotatable, even when the boom head 5d is deformed by an external force from the work table 9, a deforming force acts on the outer collar 31. There is no problem of FRP delamination at the joint between the collar and the boom head and generation of abnormal noise due to stick-slip as in the related art.

The outer collar 31 and the inner collar 32 have different hardnesses in order to prevent abnormal noise from being generated due to the relative rotation or relative movement of the outer collar 31 and the inner collar 32 and to prevent the two from sticking together. Preferably, it is made from a material that does. In this case, it is particularly preferable to select a material in which the hardness of the inner collar 32 is lower than the hardness of the outer collar 31. In this case, it is the inner collar 32 that is worn by the relative rotation or movement of the two, and as described above, the outer collar 31 is adhered to the tip boom 5c, so it is difficult to replace it.
Since the inner collar 32 can be easily replaced, it is easy to replace the inner collar 32 at the time of wear.

In the above embodiment, the nut 35 is fixed to the inside of the insertion portion 21 of the boom head 5d by welding or the like. However, the nut 35 does not have to be fixed, and when the boom head 5d is mounted. The bolt 34 may be screwed from the inside of the insulating boom 5c. Further, a female screw may be formed directly on the insertion portion 21, and this female screw may be used instead of the nut 35.

[0023]

As described above, according to the present invention,
Since the bolt fastening force acts only on the inner collar member and the boom head member and does not act on the boom tip made of an insulating material, the problem of loosening of the bolt does not occur. In addition, since the outer collar member adhesively bonded to the boom tip made of an insulating material is inserted into the inner collar member and can be relatively rotated, even when the boom head is deformed by an external force from the worktable, the outer collar member can be used. No deformation force acts on the member, and there is no problem of FRP delamination at the joint between the outer collar member and the insulating boom and generation of abnormal noise due to stick-slip.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an insulating boom head structure according to the present invention.

FIG. 2 is a perspective view showing an aerial work vehicle having an insulating boom head structure according to the present invention.

FIG. 3 is a perspective view showing a distal end boom and a boom head constituting an insulating boom head structure according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 aerial work vehicle 2 body 5 boom 5c tip boom 5d boom head 9 workbench 21 insertion part 22 support part 24 bolt insertion hole 26 boom through hole 31 outer collar 32 inner collar 33 washer 34 bolt 35 nut

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Teruichi Ito 1015-2 Yamashita, Ryoke, Ryoke, Ageo-shi, Saitama F-term in the Aichi Corporation Ageo Works (reference)

Claims (1)

[Claims] 1. An insulating boom having at least a distal end portion formed of an insulating material so as to be hollow, and a boom head inserted into the hollow space from a distal end side and attached to a distal end of the insulating boom, A boom through-hole extending in a direction perpendicular to the axial direction of the insulating boom and penetrating from the outer surface side into the hollow space is formed at the tip of the boom, and a hollow cylindrical outer collar member is provided in the boom through-hole. A hollow cylindrical inner collar member is inserted into the outer collar member, and a bolt is inserted at a position facing the inner collar member in the boom head inserted into the hollow space of the insulating boom. An insertion hole is formed, a bolt member is inserted into the inner collar member from an outer surface side with a washer member interposed therebetween, and a tip screw portion of the bolt member is inserted into the bolt. The inner collar member and the boom head are fastened and pinched by the bolt member and the nut member via the washer member by being screwed into a nut member disposed inside the boom head by being inserted therein. The outer diameter of the washer member is set to be larger than the outer diameter of the inner collar member, and the length of the inner collar member is set to be slightly larger than the length of the outer collar member. An insulating boom head structure, wherein the outer collar member is held between the boom head and the boom head.