JP2019112168A - Boom head - Google Patents

Abstract

To provide a boom head capable of using for both main hook and sub hook while achieving a weight reduction.SOLUTION: The boom head 40 comprises the left side plate 41 and the right side plate 42 arranged opposite to the boom tip, and the plural sheaves 21-23 supported rotatably between the left side plate 41 and the right side plate 42, and the plural sheaves 21-23 consists only of one upper sheave 23 arranged at the upper part between the left side plate 41 and the right side plate 42 and of the plural lower side sheaves 21, 22 arranged at the lower part between the left side plate 41 and the right side plate 42.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a boom head of a mobile crane.

  The mobile crane is equipped with a boom that can be turned and lowered. And, at the tip of the boom, a boom head provided with a plurality of sheaves (pulleys) is attached. Heretofore, various configurations have been proposed as this boom head.

  For example, in the boom head described in Patent Document 1, the main hook is pivoted upward and stored when traveling, and the sub hook is also pivoted upward and stored at the side of the main hook. There is.

JP 2004-352470 A

  However, the conventional boom head including the patent document 1 is heavy because the sheave for the main hook and the sheave for the subhook are separately provided.

  Then, an object of this invention is to provide the boom head which can be used for both a main hook and a sub hook, achieving weight reduction.

  In order to achieve the above object, the boom head of the present invention comprises a left side plate and a right side plate disposed opposite to a tip of the boom, and a plurality of sheaves rotatably supported between the left side plate and the right side plate. A plurality of sheaves, one upper sheave disposed at an upper portion between the left side plate and the right side plate, and a plurality of lower sheaves disposed at a lower portion between the left side plate and the right side plate It consists only of the side sheave.

  Thus, the boom head of the present invention is a boom head comprising a left side plate and a right side plate disposed opposite to the tip of the boom, and a plurality of sheaves rotatably supported between the left side plate and the right side plate. The plurality of sheaves are constituted only by one upper sheave disposed at the upper portion between the left side plate and the right side plate and a plurality of lower sheaves disposed at the lower portion between the left side plate and the right side plate. According to such a configuration, the boom head can be used for both the main hook and the sub hook while achieving weight reduction.

It is a side view of a rough terrain crane. It is a side view of a boom head. It is a front view of a boom head. It is an explanatory view explaining how to put out jib.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the component described in the following embodiment is an illustration, and it is not a thing of the meaning which limits the technical scope of this invention only to them.

(Constitution)
First, the whole structure of the rough terrain crane 1 as a mobile crane provided with the boom head 40 of a present Example is demonstrated using FIG. Although the rough terrain crane 1 will be described as an example of the mobile crane in the following embodiment, the present invention is not limited thereto, and the present invention is widely applicable to other mobile cranes such as cargo cranes, truck cranes and all terrain cranes. The invention can be applied

(Overall configuration of crane)
The rough terrain crane 1 of this embodiment, as shown in FIG. 1, includes a vehicle body 10 serving as a main body of a vehicle having a traveling function, outriggers 11 provided at four corners of the vehicle body 10,. It has a swivel base 12 attached to the portion 10 so as to be horizontally pivotable, and a boom 14 attached to a bracket 13 erected on the swivel base 12.

  The outrigger 11 can slide out / slide from the vehicle body 10 outward in the width direction by extending and retracting the slide cylinder, and can extend and retract the jack in the vertical direction from the vehicle body 10 by extending and retracting the jack cylinder. It is possible.

  The swivel base 12 has a pinion gear to which the power of the motor for swiveling is transmitted, and the pinion gear meshes with a circular gear provided on the vehicle body portion 10 to pivot around the swivel axis. The swivel base 12 has a cab 18 disposed on the front right side, a bracket 13 disposed in the rear center, and a counterweight 19 disposed on the rear lower part.

  The boom 14 is telescopically configured by a base end boom 141, one or more intermediate booms 142 (142a to 142d in FIG. 2), a tip boom 143, etc., which are multiple stages of boom components, and disposed inside It can be extended and retracted by the extension cylinder.

  Furthermore, in the present embodiment, the jib 50 and the tension rods 60, 60 are stored in the lower holding posture on the lower surface of the base end boom 141. The jib 50 has a Y-shape as a whole, and the base end side is bifurcated so as to be engageable with the boom tip. In the storage posture, the two tension rods 60, 60 are disposed to overlap the side of the jib 50.

  The outermost proximal end boom 141 is pivotably attached to a support shaft whose base is horizontally installed on the bracket 13, and can be raised and lowered up and down around the support shaft as a rotation center. Furthermore, a relief cylinder 15 is bridged between the bracket 13 and the lower surface of the base end boom 141, and by extending and retracting the relief cylinder 15, the whole boom 14 can be made to be up and down.

(Configuration of boom head)
And, as shown in detail in FIG. 2, a boom head 40 is attached to the tip of the tip boom 143. The boom head 40 includes a left side plate 41 and a right side plate 42 disposed opposite to each other, and an upper sheave 23 and a lower side sheave 21 as a plurality of sheaves rotatably supported between the left side plate 41 and the right side plate 42, Mainly composed of Then, on the rear side (proximal side) of the lower sheaves 21 and 22, a pin 43 with which the proximal end of the jib 50 is engaged when the jib 50 is attached is installed.

  The left side plate 41 and the right side plate 42 are formed by a metal plate so that the lower part protrudes like a jaw, and between them, the shafts of the upper sheave 23 and lower sheaves 21 and 22 and pins for the jib 50 43 are bridged and disposed to face each other in parallel. The pins 43 for the jib 50 pass through the side plates 41 and 42 and project left and right. The pin 43 for the jib 50 and the lower sheaves 21 and 22 are spaced apart by a predetermined distance so that the cable rope 16 can pass through the cable end.

  The plurality of sheaves of this embodiment is configured of one upper sheave 23 disposed at the top and two lower sheaves 21 and 22 disposed at the bottom. Among these, two lower sheaves 21 and 22 arranged at the lower part are arranged on the front side (elongation side) with respect to the upper sheave 23 arranged at the upper part when viewed in the boom extension and contraction direction. That is, the lower sheaves 21 and 22 are disposed in the protruding portions of the left side plate 41 and the right side plate 42 in the form of jaws. Here, the number of lower sheaves is not limited to two, and may be three or more. Furthermore, when not using three or more, the number of lower sheaves may be only one.

  More specifically, the pin 43 is disposed substantially directly below the upper sheave 23, and the lower sheaves 21 and 22 are disposed forward of the pin 43 (the extension side when viewed in the boom expansion and contraction direction). . That is, the pin 43 on the rear side and the lower sheaves 21 and 22 on the front side are separated by a predetermined distance.

  Similarly, in the hook (hook block) 17, two sheaves 31, 32 are disposed. Then, a wire rope 16 fed from a winch 45 (see also FIG. 4) is wound around the two lower sheaves 21, 22 and the two sheaves 31, 32 on the hook side. Note that the number of sheaves on the hook side is not limited to two, and may be one (sub hook) or three or more.

  Specifically, in the case of two hooks, the wire rope 16 is sequentially wound around the first lower sheave 21 and the first sheave 31 on the hook side, and the boom head 40 side End with In this way, the load is supported (suspended) by the two wire ropes 16 which are bridged between the boom head 40 and the hook 17.

  Similarly, in the case of four hooks, the wire rope 16 includes, in order, the first lower sheave 21, the first sheave 31 on the hook side, the second lower sheave 22 and the second on the hook side. It is wound around the two sheaves 32 and ends on the boom head 40 side. In this way, the load is supported (suspended) by the four wire ropes 16 which are bridged between the boom head 40 and the hooks 17.

(Action at jib shaking)
Next, the operation at the jib swinging out of the rough terrain crane 1 provided with the boom head 40 of the present embodiment will be described using FIG. 4.

  First, the method of jib extension will be described. The swing-out operation of the lower holding and lower swing-out type jib 50 is carried out using the rope tension of the wire rope 16 as described below. That is, first, after the boom 14 and the jib 50 are engaged in a horizontal state, the boom 14 is raised and lowered with the jib 50 held down, and the boom 14 is extended to a guide attaching the jib 50 to the boom 14 The hanging position shown in FIG.

  Next, by further winding up the wire rope 16 from the state in which the hook 17 abuts on the tip of the jib 50, the jib 50 is swung forward (toward the vertical) against the self-weight moment. That is, by pulling the wire rope 16 upward, a clockwise moment around the pin 43 acts, and the jib 50 rotates clockwise.

  At the time of swinging out, the boom head 40 of the present embodiment can efficiently shift out the jib 50. That is, since the lower sheaves 21 and 22 are disposed forward with a predetermined distance from the pin 43, it is easy to swing up the jib 50 by securing the arm length of the moment at the time of swinging out It is

  Thereafter, the proximal ends of the tension rods 60, 60 are connected to the boom head 40 side. Then, the tilt angle of the jib 50 is set by expanding and contracting the tilt cylinder (not shown), and the crane operation can be performed.

(effect)
Next, the effects of the boom head 40 of this embodiment will be listed and described.

(1) As described above, the boom head 40 is rotatably supported between the left side plate 41 and the right side plate 42 disposed opposite to the tip of the boom 14, and the left side plate 41 and the right side plate 42. A boom head 40 comprising a plurality of sheaves 21-23, wherein the plurality of sheaves are one upper sheave 23 disposed at the top between the left side plate 41 and the right side plate 42, the left side plate 41 and the right side plate And a plurality of lower sheaves 21 and 22 disposed at the lower part between 42 and 42 only. According to such a configuration, the boom head can be used for both the main hook and the sub hook while achieving weight reduction.

  That is, in the case of the boom head 40 according to the present embodiment, the minimum number of three is possible while the single sheave and the two lower sheaves 21 and 22 enable one to four hooks. The weight of the boom head 40 can be reduced by the configuration of the sheaves 21-23. For this reason, lifting performance can be improved. Furthermore, further reduction in weight can be achieved by using one wire rope 16 as well.

  Furthermore, the two lower sheaves 21 and 22 can be arranged coaxially to shorten the vertical width (the length in the boom expansion and contraction direction) of the boom head 40. This will ensure the required approach angle.

(2) Further, since the plurality of lower sheaves 21 and 22 are disposed on the front side relative to the upper sheave 23, the arm length from the pin 43 can be increased when swinging up the jib 50. , It is easy to swing up the jib 50. That is, since the lower sheaves 21 and 22 are disposed forward with a predetermined distance from the pin 43, the arm length of the moment when the jib 50 is delivered can be lengthened, and the jib 50 can be easily swung up. It has become. In addition, in the posture in which the boom 14 is raised, the lower sheaves 21 and 22 disposed on the front side are positioned upward, so that the lift can be extended as high as possible.

(3) Further, since the pin 43 with which the base end of the jib 50 is engaged when the jib 50 is attached is installed on the rear side of the plurality of lower sheaves 21 and 22, rigidity of the boom head 50 can be improved. Can be secured. That is, conventionally, there is a rotational shaft of the sheave near the position of the pin 43 of the present invention, thereby securing the rigidity. On the other hand, in the present invention, since there is no rotary shaft of the sheave at the conventional position, the pin 43 is penetrated to secure rigidity. Furthermore, by separating the rotation axes of the pin 43 and the lower sheaves 21, 22, it becomes easy to pass the cable end.

  Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes to the extent not departing from the scope of the present invention are included in the present invention. included.

1: Rough terrain crane (mobile crane);
14: Boom;
40: Boom head;
41: left side plate; 42: right side plate; 43: pin;
21: lower sieve; 22: lower sieve; 23: upper sieve;
31-33: (hook side) sieve;
50: Jib; 60: Tension rod

Claims (3)

A left side plate and a right side plate disposed opposite to the tip of the boom;
A boom head comprising: a plurality of sheaves rotatably supported between the left side plate and the right side plate;
A plurality of the sheaves are constituted only by one upper sheave disposed at the upper portion between the left side plate and the right side plate, and a plurality of lower sheaves disposed at the lower portion between the left side plate and the right side plate There is a boom head.   The boom head according to claim 1, wherein the plurality of lower sheaves are disposed forward of the upper sheave. The boom head according to claim 1 or 2, wherein a pin is provided on the rear side of the plurality of lower sheaves, with which the proximal end of the jib is engaged when the jib is attached.

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