JPH0848495A - Jib of wheel type crane, and projection thereof - Google Patents

Abstract

PURPOSE:To obviate the necessity of the complicated facilities for propulsion which can carry out the jib propulsion work in a small space in a simple manner. CONSTITUTION:A jib A is divided to a basic end side member 18 having a jib foot installed in a demountable manner on a boom head 2, and a top end side member 19 having a jib point sheave 9 at the top end part, and the jib A is assembled by connecting these elements by the first and the second connecting pins 30 and 31, and at the same time, installed on the boom head 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel type crane such as a truck crane and a rough terrain crane, which has a jib used for increasing a lifting or working radius.
Also, the present invention relates to a method for projecting a jib that projects the jib at the tip of the boom when in use.

[0002]

2. Description of the Related Art Conventionally, a compression column type jib used in a wheel type crane is constructed as a single integrated unit in the shape of a tapered ladder, and when not in use, it is a boom (basic boom).
Stored in.

Further, as a method of extending the jib from the retracted position to the tip of the boom when in use, a lateral overhang method is employed in which the jib stored on the side of the boom is swung by approximately 180 ° from side to front in a horizontal plane. As shown in JP-B-63-3827, a twist system in which a jib stored on the side surface of a boom is hung, twisted, and swung forward and extended, JP-A-55-135094 and JP-B-3-1315.
As shown in No. 7, a pulling-out method is known in which a jib stored on the lower surface or the upper surface of the boom is slid forward along the boom, and its base end is attached to the boom head and extended.

[0004]

However, according to such a method for overhanging the jib, the horizontal overhanging method (i) requires a large space for the jib to be extended on the side of the boom, so that the area is limited in the urban area. It is difficult to extend the jib at some places, and in the twist method and the withdrawal method of (ii), it is necessary to install complicated equipment for extending the jib on the boom, and the jib extension operation is complicated and troublesome. was there.

Therefore, the present invention provides a jib for a wheel type crane and a method for overhanging the jib, which allows the jib overhanging work to be easily performed in a small space and does not require complicated equipment for overhanging.

[0006]

The invention (jib) of claim 1
Is divided into a plurality of lengthwise jib constituent members including a tip end member having a jib point sheave at its tip end and a base end member having a jib foot detachably attached to the boom head. The constituent member is provided with a connecting pin hole at an end connected to an adjacent jib constituent member, and a connecting pin which is inserted into the connecting pin hole and connects adjacent jib constituent members to each other. It will be.

According to a second aspect of the present invention, in the construction of the first aspect, the tip side member is composed of a main body portion and a jib head with a jib point sheave that is detachably attached to the main body portion. is there.

According to a third aspect of the present invention, in the structure of the first or second aspect, as the connecting pin hole, the first pin hole and the second pin hole are provided so as to be displaced in the longitudinal direction, and the connecting pin hole is provided. As a pin, a first connecting pin that is inserted into the first pin hole and that temporarily joins adjacent jib constituent members to a bending state that is continuous in a middle-folded state and an extended state that is linearly continuous so as to be bendable and extendable; A second connecting pin that is inserted into the two-pin hole and that fixes the adjacent jib constituent members in the extended state is provided.

According to a fourth aspect of the present invention, in the structure of the third aspect, the refraction direction of both jib constituent members is regulated to only one direction in one of the jib constituent members to be phase-coupled to each other in a temporarily connected state by the first connecting pin. A rotation stopping member is provided.

According to a fifth aspect of the present invention, in the structure according to the first or second aspect, the connecting portions of the jib constituent members are cylindrical in shape so that males and females can be fitted between adjacent ones, and a plan view and It is formed in a corresponding trapezoidal shape in at least one side view.

The invention of claim 6 (jib overhanging method) is a method of overhanging the jib according to claim 3 or 4 from the boom head, wherein (i) the jib foot of the base end side member is attached to the boom head. Jib foot mounting process, (ii)
In a state in which the tip end side of the base end side member is grounded, a temporary connecting step of temporarily connecting the base end portions of the adjacent jib constituent members placed on the ground to the tip end portion of the same member by the first connecting pin, i
ii) An extension step of extending both members from the bent state by raising the boom next, and (iv) a fixing step of fixing both members to the extension state by the second connecting pin, wherein the jib is the tip side member. When it is composed of two members of the base end side member, the jib foot attachment, temporary connection, extension,
When the jib is bulged through each fixing step once, and the jib is composed of three or more members including both members, after the fixing step, the two adjacent members are temporarily connected, extended, and fixed. The jib is extended through the process.

[0012]

According to the constitutions of claims 1 to 5, since the jib is divided into a plurality of jib constituting members, the base end side member is attached to the boom head, and another jib constituting member is connected thereto, As soon as the jib is assembled, it can be extended to the tip of the boom.

That is, a large space for extending the jib is not required, and neither complicated equipment nor complicated operation for extending the jib is required, so that the jib extending work can be performed easily with a minimum space and equipment and simple operation. Can be done.

Further, according to the second aspect of the present invention, since the tip side member can be divided into the main body and the jib head and can be separately conveyed, the main body is made heavy, that is, the length of the main body is increased. The length of the jib can be increased.

On the other hand, according to the jib according to claims 3 and 4, and the jib overhanging method according to claim 6, the connecting work between the adjacent jib constituting members is a temporary connecting step in a bending state and an extending step for extending these. And the fixing step in this extended state, the weight of both members is supported on the ground in the temporary connection step, and it can be extended by the erecting force of the boom in the extension step and can be held in this extended state. The labor burden on the person is small. Therefore, it is possible to easily perform the jib overhanging work even though the jib is overhanging while being assembled.

Further, according to the structure of claim 4, in the extension step, the rotation preventing member prevents the tip side jib component member from over-rotating, and both jib component members are automatically held in the extended state. , Fixing work becomes easy.

Further, according to the structure of claim 5, since the connecting portion is formed into a cylindrical shape and a trapezoidal shape capable of male and female fitting, it is easy to fit and the wedge effect is exhibited in the fitted state. As a result, since no useless gap is generated between the connecting portions, the jib constituent members can be firmly connected without rattling.

[0018]

【Example】

First Embodiment (See FIGS. 1 to 11) FIGS. 1 and 2 show a jib extended state, and FIG. 3 shows a jib removed state.

In these drawings, 1 is a boom, 2 is a boom head (boom tip), and inside the boom head 2, an idler, both main sheaves 3 and 4, a lower surface (when the boom 1 is horizontally tilted) The main hook storage metal fittings 5 are provided on the lower surface of each of the main hook storage metal fittings 5 on the outer side. Stored on the bottom side.

Reference numeral 8 denotes a bracket receiving shaft (the function of which will be described later) which also serves as a central axis of rotation of the main hook storage fitting 5.

Further, on the front side of the boom head 2, as shown in FIG.
As shown in FIG. 2, an auxiliary sheave unit U including an auxiliary sheave 9 for auxiliary winding rope guide and a sheave bracket 10 that rotatably supports the sheave 9 is attached, and as shown in FIGS. Auxiliary sheave unit U
Is attached to the jib tip and used as a jib head.

The sheave bracket 10 is provided with a downward arcuate contact surface 11 on the lower side of the base end portion, and a square cylindrical common mounting portion 13 having a pin hole 12 on the upper side.

In the auxiliary sheave unit U, when the jib is removed, the common mounting portion 13 is inserted into the boom head 2 with the contact surface 11 of the sheave bracket 10 engaged with the bracket receiving shaft 8 as shown in FIG. And is attached to the boom head 2 by the bracket support shaft 14.

On the other hand, an auxiliary hook storage fitting 15 is attached to the tip of the sheave bracket 10 so as to be rotatable around a horizontal axis, and the auxiliary hook 16 is attached to the auxiliary winding rope 17 during traveling of the crane.
It is stored under the boom head together with the auxiliary hook storage fitting 15 by the hoisting force (state of phantom line in FIG. 3).

Next, the structure of the jib A will be described.

The jib A is a square pipe-shaped proximal end member 18
Is also divided into two parts in the lengthwise direction into a rectangular pipe-shaped tip side member 19, and these two members 18, 19 are connected when the jib is extended.

As shown in FIGS. 4 and 5, the base member 18 has left and right bifurcated leg portions 18a, 18a on the base end side, and the tip ends of the both leg portions 18a, 18a receive the bracket for mounting the jib. A downward bifurcated jib foot 20, which engages with the shaft 8,
20 are provided.

Further, as shown in FIG. 5, both leg portions 18a,
Plate-shaped pin guides 21 and 21 are provided between 18a and between both jib feet 20 and 20, and a jib fixing pin 22 is inserted across both pin guides 21 and 21.

The jib fixing pin 22 is moved forward and backward between a jib fixing position projecting to the jib foot side as shown by the solid line in FIG. 5 and a fixing releasing position retracting to the leg portions 18a, 18a side as shown by the phantom line. It is provided slidably in the (jib length direction), and the jib feet 20 and 20 are mounted on the bracket receiving shaft 8.
When the jib fixing pin 22 is set to the jib fixing position in a state of being engaged with, the jib feet 20 and 20 are prevented from coming off from the bracket receiving shaft 8.

In FIG. 5, 23 is a lock plate also provided on the jib fixing pin 22 and also serving as a handle for sliding operation, and 24 is a lock plate provided on the lower surface of the legs 18a, 18a. , 24 by inserting the pin 25 across the jib fixing pin 2
2 is locked in the jib fixed position.

A left and right bifurcated connecting portion 18b is provided on the distal end side of the base end member 18, and first and second pin holes 26 and 27 are provided in the connecting portion 18b with their front and rear positions displaced. ing.

On the other hand, the tip side member 19 is the base end side member 18
The auxiliary sheave unit U as a jib head is detachably attached to the tip of the main body portion 33 connected to.

As shown in FIG. 4 and the like, the tip end side member 19 has a first end corresponding to a base end portion (connecting portion) 33a of the main body portion 33 and both pin holes 26 and 27 of the base end side member 18. And the second both pin holes 28, 29 are provided, and in the state where the base end portion 33a of the main body portion 33 is fitted into the connecting portion 18b of the base end side member 18, the both pin hole portions 26, 27, 28, 29 of each other. Both the first and second pins 30 and 31 are inserted into the
8, 19 are connected.

Further, a rotation stop plate 32 is provided on the upper surface of the tip end portion of the base end side member 18 so as to face the connecting portion 18b, and one end of the tip end side member 19 relative to the base end side member 18 in one direction of the jib overhanging process which will be described later. The rotation is stopped by the rotation stop plate 32.

Further, a pin hole 34 is provided at the tip of the main body portion 33 so as to penetrate left and right, and the common mounting portion 13 of the sheave bracket 10 in the auxiliary sheave unit U is the tip portion of the main body portion 33 when the jib is extended. The auxiliary sheave unit U is attached to the tip of the main body 33 by inserting the pin 35 into the pin holes 12 and 34 of the auxiliary sheave unit.
Are attached to form the tip side member 19.

As shown in FIGS. 2 and 4, the jib A has the jib feet 20, 20 inserted into the boom head 2 to engage the bracket receiving shaft 8 and is prevented from coming off by the jib fixing pin 22. It is attached to the boom head 2 and is supported by a tension rope 36 suspended between the boom head 2 and the jib tip.

Further, a stopper 37 is attached between the base end of the jib and the boom head 2, and the stopper 37 prevents the jib A from being inverted (raised) during jib work. Reference numeral 38 denotes a stopper mounting bracket to which the jib side end of the stopper 37 is mounted.

When the jib is stored, the stopper 37 is reversed to the front as shown in FIG. 7, and the front end portion in this reversed state is pin-fixed to the storage bracket 39.

On the other hand, FIGS. 6 and 7 show the construction of a jib storage unit for storing the jib A in a divided state when not in use.

In the figure, L is a lower traveling body, C is a carrier frame of the lower traveling body L, and 40 is a front bumper provided at a front end portion of the carrier frame C.
A jib storage section 41 is provided below the front bumper 40.

The jib storage section 41 has two jib receiving frames 42, 4 having a U-shaped cross section, which is shorter than the width dimension of the lower traveling body L.
3 is a front bumper 40 in a horizontal state adjacent to the front and rear.
It is configured to be mounted on the lower surface of the vehicle in the traveling body width direction and within the traveling body width. The front jib receiving frame 42 has a body portion 33 of the tip side member 19 of the jib A, and the rear jib receiving frame 43 has a base end side member. 1
8 are mounted and housed.

6 and 7, reference numerals 44, ... Are mounting members for collectively mounting both jib receiving frames 42, 43 on the lower surface of the front bumper, 45, 45 are outriggers on the front left and right sides, and 46 are front wheels. Is.

Next, the procedure for extending the jib A will be described.

(A) As shown in FIGS. 6 and 7, the outrigger 4 is
8, the boom 1 is maximally tilted as shown in FIG. 8, the auxiliary winding rope 17 (auxiliary hook 16) is loosened, and the auxiliary sheave unit U is removed from the boom head 2.

(B) As shown in FIGS. 5 and 9, the jib feet 20 and 20 of the jib base end member 18 are attached to the bracket receiving shaft 8.
And is locked by the jib fixing pin 22.

(C) As shown in FIG. 9, the base end member 18
Tip side member 1 placed on the ground with the tip of the grounded
The base end portion of the main body portion 33 in 9 is fitted into the connecting portion 18b of the base end side member 18 and is temporarily connected only by the first connecting pin 30. At this time, the base end side member 18 and the tip end side member main body portion 33 are in a bending state in which the base end side member 18 and the tip end side member main body portion 33 are continuously bent in a middle shape.

The base end side of the stopper 37 is attached to the boom head 2.

(D) As shown in FIG. 10, after the base end side of the tension rope 36 is fixed to the boom head 2, the boom 1 is slightly raised and the base end side member 18 and the tip end side member main body portion 33 are linear. Then, the second connecting pin 31 fixes this extended state.

At this time, the anti-rotation plate 32 prevents the distal end side member main body portion 33 from excessively rotating, and both are automatically held in the extended state, so that the fixing operation is simplified.

(E) The auxiliary sheave unit U is attached to the tip of the tip side member body 33 by the pin 35. This completes the assembly of the jib A.

(F) As shown in FIG. 11, the boom 1 is slightly tilted to change the jib angle, and the tip end side of the tension rope 36 is fixed to the jib A.

Thereafter, the boom 1 is raised to complete the extension of the jib A.

The removal of the jib A is the reverse of this procedure.
The jib A that has been removed by operation is removed from the base member 18
And the main body portion 33 of the distal end side member 19 are separately stored in the jib storage portion 41 of the lower traveling body L. The auxiliary sheave unit U is attached to the boom head 2 as before.

In this way, the jib A is divided into the base end side member 18 and the tip end side member 19, and the jib A is assembled by connecting them to each other and at the same time, the jib A is extended to the tip of the boom. In addition to eliminating the need for a jib, neither complicated equipment nor a complicated operation for jib overhanging is required, and the jib overhanging work can be easily performed with a minimum space and equipment and a simple operation.

Further, since the tip side member 19 can be divided into the main body 33 and the jib head (auxiliary sheave unit U) and can be carried separately, the main body 33 is heavy, that is, the length of the main body 33 is long. The length of the jib can be increased.

On the other hand, both the base end side member and the front end side member 18, 1
9, the temporary connecting step (FIG. 9) with the first connecting pin 30 in the bent state, the extending step (FIG. 10) for extending these, and the fixing step with the second pin 31 in the extended state ( It is possible to support the weight of both members on the ground in the connecting process, to extend the boom by the erecting force of the boom in the extending process, and to maintain the extended state. I'm sorry.

Further, in this embodiment, the jib A can be disassembled and stored in the lower traveling body L when not in use, so that the jib A can be used for crane work in a narrow place as in the case where the jib A is stored. There is no risk of obstruction at times, reduction of suspension capacity due to increase of boom weight, obstruction of visibility during crane traveling, and deterioration of traveling stability.

Since the jib head (auxiliary sheave unit U) can be removed when the jib is stored,
The length of the main body portion 33 of the distal end side member 19 can be increased to increase the total length of the jib.

Further, since the auxiliary sheave unit U, which is unnecessary during jib work, can be used also as the jib head, the number of parts can be reduced and the cost can be reduced.

Second Embodiment (see FIGS. 12 to 16) Only differences from the first embodiment will be described.

The jib B of the second embodiment is provided with both the base end side member 47 and the front end side member 47, which are formed in the shape of a frame that is tapered toward the tip end side of the jib, and these members face each other. The connection portions 49 and 50 provided at the ends are detachably connected.

Reference numeral 48a denotes a main body portion of the tip side member 48,
As in the case of the embodiment, the auxiliary sheave unit U is attached to the main body portion 48a by the pin 35 to form the tip side member 48.

Both the connecting portions 49 and 50 are formed in a rectangular tube shape, and the connecting portion of the base end side member 17 (hereinafter referred to as the male side connecting portion) 49 is connected to the connecting portion of the distal end side member 48 (hereinafter referred to as the female side connecting portion). (Referred to as a part) 50.

Further, the two connecting portions 49, 50 are each formed in a trapezoidal shape which is tapered in a plan view toward the tip end of the jib, and the gap between the side surfaces thereof is zero in the fitted state. Each width dimension is set as follows.

According to this structure, when the fitting is performed, since the dimensional difference between the fitting start ends is large, the fitting is facilitated, and the wedge effect is exhibited in the fitted state, so that a wasteful gap is provided between the fitting portions. Therefore, both members 47 and 48 can be firmly connected without rattling.

It should be noted that pads 51, 51 are provided on the outer surface of the male-side connecting portion 49, and both connecting portions 49, 50 are provided.
Considering the case where there is an error in the width dimension of the pads 51, 5
A shim 52 is provided between the outer peripheral surface of the male-side connecting portion 49 and the outer peripheral surface of the male-side connecting portion 49, and the gap 0 can be maintained by increasing or decreasing the number of the shim 52.

Further, pin holes 53 and 54 are provided in the central portions of both connecting portions 49 and 50, and a connecting pin 55 is inserted across the both pin holes 53 and 54. 56 is a connecting pin 55
It is a retainer pin.

In the case of the construction of the second embodiment, the jib B is assembled by connecting both the base end side member 47 and the tip end side member 47 on the ground, and then the jib B is set as shown in FIGS. The procedure for attaching to the boom head 2 may be taken. Alternatively,
It is also possible to first attach the base end side member 47 to the boom head 2 and then connect the tip end side member 48 thereto.

When using the jib B, the compression force,
That is, since only the force in the direction in which the connecting portions 49, 50 of both the base end side member 47 and the distal end side member 47 are more strongly fitted to each other, the connecting pin 55 is subjected to an unexpected external force due to vibration or the like under no load condition. It functions only as a safety pin that prevents both connecting parts 49, 50 from coming off.

On the other hand, the second embodiment differs from the first embodiment in the following points in addition to the construction of the jib B.

First, as shown in FIGS. 12 and 13, the boom head 2 is provided on both sides of the base end portion of the jib B (base end side member 47).
A pair of jib feet 5 with a spacing larger than the width dimension of
7 and 57 are provided, and these jib feet 57 and 57 are
The bracket receiving shaft 8 is engaged with the outside of the boom head 2 and the outside of the main double housing fitting 5, and is fixed by a fixing pin (not shown).

Second, as shown in FIGS. 12 and 13, jib B
On the upper surface of the tip of the tip side member 48 of the tension rope 3
A rope fastening bracket 58 to which the tip end of 6 is fastened is provided over three stages in the rope length direction, and the offset angle of the jib B is set to 3 by selecting the fastening point of the tension rope 36 from these. It is configured so that it can be arbitrarily selected and changed among the steps.

When the jib offset angle is the smallest (for example, 5 °), the tip of the jib B floats above the ground when the boom 1 is maximally tilted.

Therefore, when the tip end side of the tension rope 36 is fixed to the frontmost end rope fixing bracket 58 at the time of attaching the jib, it is necessary to manually lift the tip end side of the jib to float from the ground. Alternatively, the tip of the jib may be grounded by inclining the vehicle body toward the jib side by the outrigger.

Other Embodiments (1) In both of the above embodiments, the jibs A and B are connected to the base member 18,
Although it is divided into two, 47 and the tip side members 19 and 48, when the jib length is long, it may be divided into three or more jib constituent members.

In this case, when the connecting structure of the first embodiment is adopted, after the base end side member 18 is attached to the boom head 2, the base end side member 18 and the intermediate member, the intermediate members, and the intermediate member and the tip side. The member 19 may be subjected to the temporary connecting step in FIG. 9 and the extending and fixing step in FIG.

(2) In both of the above embodiments, the auxiliary sheave unit U is also used as the jib head, but a dedicated jib head may be used.

Further, the jib head is attached to the tip side member 19,
It may be provided integrally (non-detachable) with the main body 33, 47a of 47.

(3) As a modified example of the second embodiment, both connecting portions 49, 50 may be formed in a trapezoidal shape not only in a plan view but also in a side view.

Alternatively, both connecting portions 49, 50 may be formed in a straight cylindrical shape instead of such a trapezoidal shape, and these may be connected by one or a plurality of pins in a fitted state.

(4) In the above embodiment, the jib A is stored in the lower traveling body L in a divided state, but it may be stored in the boom 1 as in the conventional case.

[0082]

As described above, according to the present invention, the jib is divided into a plurality of jib constituent members, which are connected to each other at their connecting portions to assemble the jib and to be attached to the boom tip. Since it is configured to extend, there is no need for a large extension space when extending the jib, and neither complicated equipment nor complicated operation for extending the jib is required, and the jib extension work is simplified with the minimum space and equipment, and simple operation. Can be done.

Further, according to the invention of claim 2, since the distal end side member can be divided into the main body portion and the jib head and can be separately conveyed, the main body portion is made heavy, that is, the length of the main body portion is increased. The length of the jib can be increased.

On the other hand, according to the jib according to claims 3 and 4 and the jib overhanging method according to claim 6, the connecting work between the adjacent jib constituent members is a temporary connecting step in a bending state and an extending step for extending these. And the fixing step in this extended state, the weight of both members is supported on the ground in the temporary connection step, and it can be extended by the erecting force of the boom in the extension step and can be held in this extended state. The labor burden on the person is small. Therefore, it is possible to easily perform the jib overhanging work even though the jib is overhanging while being assembled.

Further, according to the invention of claim 4, in the extending step, the rotation preventing member prevents the jib constituent members on the distal end side from excessively rotating, and both jib constituent members are automatically held in the expanded state. , Fixing work becomes easy.

Further, according to the fifth aspect of the invention, since the fitting portion as the connecting portion is formed in a trapezoidal shape, it is easy to fit, and the wedge effect is exerted in the fitted state, and the fitting portion Since no unnecessary gap is generated in the jib, the jib constituent members can be firmly connected to each other.

[Brief description of drawings]

FIG. 1 is a schematic side view of a first embodiment of the present invention with a jib extended.

FIG. 2 is a partially cutaway enlarged view of FIG.

FIG. 3 is a view corresponding to FIG. 2 with the jib removed.

FIG. 4 is a perspective view of both a proximal end side member and a distal end side member that constitute the jib in the same embodiment.

FIG. 5 is an enlarged cross-sectional view of a base end portion of the jib.

FIG. 6 is a side sectional view of the jib storage portion in the embodiment.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a side view showing the first stage of the jib overhanging procedure.

FIG. 9 is a side view showing the second stage.

FIG. 10 is a side view showing the third step.

FIG. 11 is a side view showing the fourth step.

FIG. 12 is a schematic side view showing a second embodiment of the present invention in a jib overhanging state.

FIG. 13 is a schematic plan view of the same.

FIG. 14 is a partially enlarged view of FIG.

15 is an enlarged sectional view taken along line XV-XV in FIG.

FIG. 16 is a plan view of the portion shown in FIG. 13 before connection.

[Explanation of symbols]

A Jib 18 Base end side member forming a jib 20, 20 Jib foot 26 First pin hole 27 of the base end side member 27 Same second pin hole 19 Tip side member 33 forming a jib Main body of tip side member Also used for U jib head Auxiliary sheave unit 9 Auxiliary sheave of auxiliary sheave unit (jib point sheave) 10 Sheave bracket 28 First pin hole of tip side member 29 Second pin hole 30 First connecting pin 31 Second connecting pin 32 Rotation stop plate (Anti-rotation member) B jib 47 Base end side member constituting the jib 48 Same tip end side member 49 Trapezoidal connecting part (male side connecting part) of base end side member 50 Trapezoidal connecting part (female side) (Side connection part)

Claims (6)

[Claims] 1. A lengthwise plurality of jib constituent members including a tip end member having a jib point sheave at a tip end thereof and a base end member having a jib foot detachably attached to a boom head, The jib of a wheel type crane, wherein each of these jib constituent members is provided with a connecting portion that is detachably connected to an adjacent jib constituent member. 2. The wheel type crane according to claim 1, wherein the tip side member is composed of a main body portion and a jib head with a jib point sheave detachably attached to the main body portion. jib. 3. A jib structure in which a first pin hole and a second pin hole are provided in the connecting portion of each jib constituent member so as to be displaced in the length direction, and the jib structure is inserted through the first pin hole and adjacent to each other. A first connecting pin that temporarily connects the members to each other in a bending state that is continuous in a middle-bend shape and an extension state that is linearly continuous so that the members can bend and expand, and the jib constituent members that are adjacent to each other and are inserted into the second pin hole are extended. The jib of the wheel type crane according to claim 1 or 2, further comprising a second connecting pin that is fixed in a state. 4. A detent member for restricting the refraction direction of both jib constituent members to only one direction in a temporary connection state by the first connecting pin is provided on one of the jib constituent members to be phase-coupled. The jib of the wheel type crane according to claim 3. 5. The connecting portion of each jib constituent member is formed in a cylindrical shape that allows male and female fitting between adjacent ones, and has a trapezoidal shape corresponding to each other in at least one of a plan view and a side view. The jib of the wheel type crane according to claim 1 or 2 characterized by things. 6. A jib overhanging method of overhanging the jib according to claim 3 or 4 from a boom head, comprising: (i) a jib foot attaching step of attaching the jib foot of the base end side member to the boom head; and (ii) this base. A temporary connecting step of temporarily connecting the base end portions of the adjacent jib constituent members placed on the ground to the front end portions of the end side members by grounding the front end sides of the end members with the first connecting pin; Next, a boom is raised to extend both members from the bent state, and (iv) a fixing step of fixing both members to the extended state by a second connecting pin, wherein the jib has a tip side member and a base end. In the case where the jib is composed of two members, the jib foot is attached, provisionally connected, extended, and fixed once to project the jib, and when the jib is composed of three or more members including both members. , After the fixing process A method for overhanging a jib of a wheel type crane, wherein the jib is overhanged through the above-mentioned steps of temporary connection, extension, and fixation of two adjacent members.