JPH0597392A - Jib installation device for crane - Google Patents

Abstract

PURPOSE:To engage a hollow shaft and an engagement hole on a boom head by inserting an engaging pin when a jib is accommodated into the top part boom of an extensible/contractible boom without forming a new engagement hole on the side plate of a jib head by fixing the hollow shaft which supports a shieve, on the side plate of the jib head. CONSTITUTION:A jib 30 in which a shieve 48 is supported on a hollow shaft 47 fixed at the center of the top part of the side plate 41 of a jib head 40 is installed so as to be accommodated in the top part boom 10D of an extensible/ contractible boom 10, and at the accommodation position, the hollow shaft 47 and an engagement hole 28 on a boom head 12 are fitted, and engaged by an engaging pin 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jib mounting device in a crane, and more particularly to a jib mounting device in a crane in which a jib is retractable in a top boom of a telescopic boom.

[0002]

2. Description of the Related Art As a jib mounting device in a crane in which a jib is stored in a top boom of a conventional telescopic boom, there are, for example, those shown in FIGS. FIG. 8 is a schematic side view of a main part thereof, and FIGS. 9 and 10 are vertical cross-sectional explanatory views taken along lines DD and EE of FIG.

As shown in FIGS. 8 to 10, this is a top boom of a telescopic boom 10 of a wheel crane with a jib (see the reference numeral "1" in FIG. 4 showing an embodiment of the present invention). -The Jib body 31 and the jib head 40 provided so as to be able to bend the jib body 30 are provided in the hole 10D so that the jib 30 can be stored and held, and the U-shaped handle for attachment / detachment operation provided on the outside of the side plate 41 of the jib head 40. 52, holding the jib head 40
Is rotated clockwise about its mounting shaft 36 (FIG. 8) to move the jib main body 3 to the position shown in FIG.
1. After standing up in a straight line on the extension line of 1 or at the same time as standing up of the jib head 40, a locking hole 33 provided in the base portion of the side plate 32 of the jib body 31 and a boom head of the top boom 10. After pulling out the locking pin 29 that is inserted into the locking hole 28 provided in the side plate 12A of 12, the jib 3
0 is stored in the top boom 10D, and a locking hole 60 provided in the central portion of the side plate 41 of the jib head 41 and the boom head 1
The locking pin 29 is inserted into the locking hole 28 of the side plate 12A of the second side to hold the jib 30 at the storage position thereof, and the wheel crane 1 without holding the jib 30 at the storage position. Enable running.

When the jib 30 stored in the top boom 10D of the telescopic boom 10 is pulled out, first, the jib head 40 is drawn.
The locking pin 29 is pulled out from the locking hole 60 of the boom head 12 and the locking hole 28 of the boom head 12 to release the locked state of both, and the grip 52 for mounting and dismounting provided on the side plate 41 of the jib head 40 is grasped. Then, after pulling out the jib 30 from the top boom 10D, the locking pin 29 is inserted into the locking hole 33 of the side plate 32 of the jib body 31 and the locking hole 28 of the boom head 12 and locked. Then, the jib 30 is locked in the withdrawn position.

After that, the jib head 40 at the position indicated by the alternate long and short dash line 40A in FIG. 8 is attached to the jib body 31 in the mounting hole 35 at one side apex (the lower left side in FIG. 8) of the side plate 32a at the top of the jib body 31. After being inserted and rotated around the mounting shaft 36 in the counterclockwise direction and bent to the solid line position, the locking hole 43 of the side plate 32a at the top of the jib body 31 and the jib head 40 are bent.
Aligning with the locking hole 43 of the side plate 41, the locking pin 38 is inserted to secure the bending state of the jib head 41, and the expansion and contraction of the expansion and contraction boom 10 and its undulation and the main winding winch motor (not shown). Sheaves 12B and 12C of the boom head 12
A wire rope (reference numeral "16" in FIG. 4 showing an embodiment of the present invention) stretched around the wire is wound up and unwound, and a wire rope is hung on the sheaves 46 and 48 of the jib head 40. (Not shown) is wound by a supplementary winch motor (not shown) installed in the vicinity of the main winch motor, and is unwound by the same jib 30.

If necessary, the boom head 1 is used.
Wire rope 1 stretched over two sheaves 12B and 12C
Hook suspended on 6 and sheave 4 of jib head 40
To the hook at the end of the wire rope stretched over 6, 48,
The suspended load is applied at the same time and the cargo is handled.

Numeral 33a is a locking hole provided at the center of the top portion (left side in FIG. 8) of the side plate 32 of the jib body 31, which is the top portion.
This locking hole 33 of the jib 30 that is slightly pulled out from the frame 10D
a and the locking hole 28 of the side plate 12A of the boom head 12 are aligned, and the locking pin 29 is inserted to lock the jib 30 on the top boom 10D. In this state, the jib head 4
Wire sheaves (not shown) are hung on the sheaves 46, 48 of 0, and the same cargo handling operations as described above are performed by the auxiliary winding winch (not shown).

[0008]

However, in the jib mounting device in such a conventional crane, it is necessary to secure the storage position of the jib 30 in the top boom 10D. Side plate 12A of the boom head 12
And the side plate 41 of the jib head 40.
The locking pin 60 is inserted into the locking hole 60 provided in the central portion of the jib head 40, and thus the locking pin 29 is inserted into the central portion of the side plate 41 of the jib head 40. It is necessary to provide a hole 60, and this locking hole 6
On the side plate 41 around 0, the jib 30 is attached to the top boom 1
In the state of being stored in 0D, the impact force based on the vibration generated when the wheel crane 1 including the expansion boom 10 is run is transmitted through the locking pin 29, It is necessary to secure the strength of the central portion of the side plate 41 which has been lowered due to the formation of the locking hole 60. Therefore, the plate thickness of the side plate 41 is increased or a hole is formed around the locking hole 60 of the side plate 41. It was necessary to take some reinforcement measures around the same side plate 41 or the perforated portion of the insertion hole 60, such as by welding the reinforcing plate 61 with 62.

Further, it goes without saying that the jib head 40
If the plate thickness of the side plate 41 is increased or the reinforcing plate 61 is welded around the locking hole 60 of the side plate 41, the weight of the side plate 41 or the jib head 40 is increased, and the side plate 41 is locked to the side plate 41. This leads to an increase in processing man-hours such as drilling of the hole 60 and fixation of the reinforcing plate 61 with the hole 62 around the locking hole 60 by welding, which increases the weight of the jib 30 including the jib head 40.
There was a problem of causing the cost increase.

The present invention has been made in view of the above problems in the prior art, and in a crane in which a jib can be stored in the top boom of the telescopic boom, the jib head of the jib is stored. The sheave is supported by a hollow shaft provided at the center of the top of the side plate, and the sheave provided on the side plate of the boom head in a state where the jib is stored in the top boom.
The hollow shaft for bearing support is aligned with the locking hole provided in the top boom so that the locking pin can be inserted, without providing a new locking hole in the side plate of the jib head. An object of the present invention is to provide a jib mounting device in a crane that can solve the above-mentioned problems without increasing the plate thickness of the same-side plate or constructing a reinforcing means such as welding a reinforcing plate with holes to the same-side plate. To do.

[0011]

In order to solve the above-mentioned problems of the prior art, the present invention provides a jib having a bendable jib head so that it can be stored in the top boom of the telescopic boom. In the crane, the sheave is supported via a hollow shaft provided at the central apex of both side plates of the jib head, and the jib is raised with respect to the jib body so that the jib head is raised. In the state of being stored in, the locking pin is removably provided in the hollow shaft and the locking hole of the top boom.

(Operation) Since the present invention has the above-mentioned structure, the jib in which the jib head is erected in a straight line with respect to the jib body is provided in the top boom of the telescopic boom of the crane. After the insertion, the hollow shaft for sheave support provided on the central top of the side plate of the jib head and the locking hole of the top boom are fitted to each other and the locking pin is inserted. Secure it in the storage position, remove the locking pin, pull out this jib from the top boom, align the locking hole of the jib body with the locking hole of the top boom, and insert the locking pin. Then, the jib is attached to the position where it is pulled out from the top boom, and the required loading and unloading work is performed by the jib.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a jib mounting device in a crane according to the present invention will be described below with reference to FIGS. The same names and reference numerals are used for the parts common to the jib attachment device in the conventional crane shown in FIGS.

[0014]

First Embodiment First, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the jib 30 of the first embodiment of the present invention is pulled out from the top boom 10D, and the locking hole 33 at the base thereof and the locking hole 28 of the boom head 12 of the top boom 10D are fitted together. While the stop pin 29 is inserted and locked, the jib head 40 is rotated around the mounting shaft 36 with respect to the jib body 31, and is bent downward in FIG. 1, which is a schematic side view, FIG. 2 and FIG. Are lines A-A and B in FIG.
4 is a vertical cross-sectional explanatory view taken along line B, and FIG. 4 is a side view of the wheel crane 1 embodying the present invention. In FIG.
Is stored in the top boom 10D. FIG. 5 is a side view for explaining a state in which the jib head 40 is extended on the jib body 31 so as to form a straight line and is stored in the top boom 10D indicated by a chain line.

1 to 5, 1 is a wheel crane, 2 is a lower traveling body, 3 is a vehicle base, 4 is a swing bearing, 5 is an outrigger, 6 is an engine cover, and 7 is an upper swing. Body, 8 is a driver's cab for both driving operation and cargo handling operation,
Reference numeral 10 is a telescopic boom, 10A is a base boom, 10D is a top boom, and 11 is a base of the base boom 10A, which is rotatably attached to the top of a right-angled triangular top plate 23 of a swivel frame 22. Foot pin, 12 is a boom head, 13 is a hoisting cylinder, 15 is a mounting shaft between the hoisting cylinder 13 and the base boom 10A of the telescopic boom 10, 16 is a wire rope, 17 is a hook block, 28 Is a locking hole provided in the center of the side plate 12A of the boom head 12 of the top boom 10D, and 29 is a locking pin.

30 is a top boom 10D of the telescopic boom 10.
Jib that can be stored inside, 31 is the jib body of jib 30, 32
Is a side plate of the jib body 31, 32a is a side plate at the top of the jib body 31, and the distance between the side plates 32a and 32a is smaller than the distance between the side plates 32 and 32 of the jib body 31 as shown in FIG. Reference numeral 33 is a locking hole provided at the center of the base portion (right side in FIG. 1) of the side plate 32, 33a is a locking hole provided at the center of the top portion (left side in FIG. 1) of the side plate 32, 34 is a stopper, and 35 is a jib body. 31 is a mounting hole provided on one side of the top of the side plate 32a at the top (lower left side in FIG. 1), and 36 is a mounting shaft to be inserted into a mounting hole 35 of the side plate 32a of the top of the jib body 31 and a hole at the base of the side plate 41 of the jib head 40. The mounting shaft 36 allows the jib head 40 to mount the mounting hole 3 of the side plate 32a on the top of the jib body 31.
It is attached so as to be rotatable around 5.

37 is a locking hole provided on the other side of the side plate 32a at the top of the jib body 31 (upper left side in FIG. 1), 38 is a locking pin, and the locking pin 38 is the top side plate 32a of the jib body 31. The engaging hole 37 and the jib head 40 of the mounting shaft 3
By turning around 6, the locking holes 42 or 43 provided on the one side and the other side of the base of the side plate 41 are alternately aligned (the locking hole 42 and the locking hole 37 are matched in FIG. 1). And the jib head 40 is locked at the position indicated by the solid line 40 or the position indicated by the alternate long and short dash line 40A in FIG.

Reference numeral 45 denotes a mounting shaft for attaching the sheave 46 to the side plate 41 of the jib head 40, and 47 denotes a sheave 48 to the side plate 41.
This is a hollow mounting shaft to which the side plate 4 is attached.
1 is fixed to the central top portion (the lower central portion when the jib head 40 of FIG. 1 is bent with respect to the jib body 31) by welding or the like. The wire roll 44 is provided on the side plate 41 around the sheave 48, is stretched around the sheave 48, and is wound and rewound by an auxiliary winding winch (not shown).
It is a pin to prevent the cap from coming off.

Reference numeral 51 is an insertion hole for a grip fist N provided substantially at the center of the side plate 41 of the jib head 40, and 52 is a grip fist insertion hole 4
1 is a claw-shaped handle for jib attachment / detachment provided on the outer side of the same side plate 41, and N ₀ is a height protruding inward from the handle 51 of the grip fist N, that is, the jib head 31 by the grip fist N. Nagiri fist N is jib head 40
The height B _{1 of the} handle 52 is lower by the height Na than the case where the side plate 41 is not provided with the insertion hole 51 for the grip fist N at the height inserted from the outer surface of the side plate 41. It

Reference numeral 53 designates both side plates 41, 4 of the jib head.
The reinforcing ring 53 is a reinforcing ring fixed to the inner edges of the insertion holes 51, 51 of the grip fist N provided in FIG.
By welding, the central portions of both side plates 41, 41 of the jib head 40 are reinforced and the grip fist N inserted into the insertion hole 51 is protected.

(Operation of the First Embodiment) First, the wheel crane 1 is moved to a desired cargo handling work place, set to a required position by extending the outrigger 5, and then the upper swing body 7 is swung. Expansion boom with undulating cylinder 13
0 undulation and its expansion and contraction, and the wire rope 16 is wound and unwound by a main winding winch (not shown) provided at the rear of the swivel frame 22, and the hook block 17 is used for loading and unloading work. After the jib head 40 is released from the jib head 40 and the locking pin 29 of the jib head 40 and the locking hole 28 of the boom head 12 of the top boom 10D is released, the jib head is removed. 40 side plates 4
The grip 52 for loading / unloading the jib 30 provided on the outer side of the jib 30 is grasped and pulled out, and engaged with the locking hole 33 at the base of the side plate 32 of the jib body 31 and the locking hole 28 of the side plate 12A of the boom head 12. The stop pin 29 is inserted and locked to secure the jib head 40
In the point that a wire rope (not shown) is hung on the hook 48, the auxiliary winding winch (not shown) is used for winding and rewinding, and a cargo handling operation is performed through a hook at an end thereof.
It works almost the same as Lucrane 1.

Further, the jib head 40 is rotated counterclockwise around the mounting shaft 36 on one side top portion (lower left side in FIG. 1) of the side plate 32a on the top portion of the jib body 31, and the jib head 4 is rotated.
No. 0 side plate 41 on one side of the base portion (the upper right side of the jib head 40 in the solid line position in FIG. 1) is provided with a locking hole 42.
1 Aligning with the locking hole 37 on one side of the top of the top side plate 32a (upper left side in FIG. 1), insert the locking pin 38 to lock.
The state of FIG. 1 in which the jib head 40 is bent with respect to the jib body 31 is ensured. Conventionally, the bent sheaves 46 and 48 of the jib head 40 are hooked with a wire rope (not shown), wound by an auxiliary winch (not shown), rewound, and a cargo handling operation is performed through a hook at the end. It operates in substantially the same manner as the wheel crane 1 of the same type.

In this first embodiment, the jib 30 is attached to the top boot.
Jib 30 that is stored by inserting it into the system 10D
When pulling out from the top boom 10D, the U-shaped handle 51 is provided at approximately the center of both side plates 41, 41 of the jib head 40.
Jib 30 including the jib head 40
Is inserted into the top boom 10D, and the inserted jib 30 is pulled out from the top boom 10D.

At this time, since the insertion hole 51 of the grip fist N is provided at approximately the center of the side plate 41 of the jib head 4, most Na of the height N ₀ of the grip fist N is the insertion hole 5 of the grip fist N.
1, the rising height B from the same side plate 41
₁ is the height Na inserted into the insertion hole 51 of the grip fist N
It can be constructed as a handle 52 having a considerably low height, and the width B of the entire jib head 40 is constructed so narrow.

In the first embodiment, the end of the hollow shaft 47 that supports the sheave 48 is fixed to the center of the top of the side plate 41 of the jib head 40 by welding or the like, and the jib 30 is attached to the top of the jib head 40. Since the hollow shaft 47 is disposed at a position matching the locking hole 28 of the boom head 12 when inserted and stored in the boom 10D, the hollow shaft 47 and the locking hole 28 of the boom head 12 are arranged. And lock pin 2
9 is inserted and both are locked, and the jib head 40 is secured in the storage position in the top boom 10D.

The jib 30 is fixed to the center of the top of the side plate 41 of the jib head 40 by welding or the like, and the locking pin 2 is inserted into the hollow shaft 47 that supports the sheave 48.
Since it is supported in the engagement hole 28 of the boom head 12 via the engagement pin 9, the impact force due to the vibration generated by the running of the wheel crane 1 or the like is applied to the engagement pin 29.
After being transmitted to the hollow shaft 47 via the
7 and the side plate 41 of the jib head 40 are widely dispersed and transmitted to the side plate 41 through a fixing portion such as welding, and stress concentration on the side plate 41 does not occur due to this impact force.

The jib head 40 is mounted on one side of the side plate 32a on the top of the jib body 31 so as to be bendable with respect to the jib body 31 via a mounting shaft 36, and the jib head 40 is attached to the jib body 31. And bend it to an appropriate angle by alternately engaging the locking holes 42 or 43 of the side plate 41.
Since the locking pin 37 is inserted into the locking hole 37 of the 2a so that the locking can be performed, the jib head 40 can be fixed to the jib body 31 without providing a new locking hole in the side plate of the jib head 40. Can be locked at the required angle.

Also, the jib 30 is mounted by locking the locking pin 29 in the locking hole 28 of the boom head 12 of the top boom 10 of the telescopic boom 10 and attaching the top boom 10D. When carrying out cargo handling work or the like by the auxiliary winding wire rope pulled out through the sheaves 46 and 48 of the jib head 40,
The auxiliary winding wire rope stretched around the sheaves 46 and 48 of the jib 30 is guided away from the jib body 31, the top boom 10D, the boom head 12 thereof, the sheave 12C thereof and the like. There is no risk that the wire rope will interfere with them.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same names and reference numerals are used for the parts common to the first embodiment shown in FIGS. 1 to 5.

FIG. 6 is a side view for explaining the main part of the second embodiment of the present invention, and FIG. 7 is a vertical cross-sectional view for explaining the CC line of FIG. 6 and 7, 10 is a telescopic boom, 10D
Is a top boom, 10DD is a side plate of the top boom 10D, 1
2 is a boom head, 12A is a side plate of the boom head 12,
12B and 12C are sheaves provided on the boom head 12,
Reference numeral 28 denotes a locking hole provided in the side plate 12A of the boom head 12.

Reference numeral 30 designates a jib that can be inserted and stored in the top boom 10D, 31 a jib body of the jib 30, 32 a side plate of the jib body 31, 32a a side plate of the top of the jib body 31, and this side plate 32a. And 32a are separated by the jib body 3
It is configured to be narrower than the space between the both side plates 31, 31 (see FIG. 3 of the BB sectional view of the first embodiment). 33 is the side plate 3
2 is a locking hole provided at the base (right side in FIG. 6), 33a is a locking hole provided at the top of the same side plate 32 (left side in FIG. 6), 35
Is a mounting hole provided on one side of the top of the side plate 32a (lower left side in the figure), and 36 is a mounting shaft to be inserted into the mounting hole 35. It is rotatably mounted in a mounting hole 35 on one side of the top of the side plate 32a. 37 is a locking hole provided on the other side (upper side in the figure) of the side plate 32a of the jib body 31, 38 is a locking pin, and the locking pin 38 attaches the jib head 40 to the jib body 31. The side plate 4 is rotated around the shaft 36.
One of the locking holes 42 and 43 provided in the base portion 1 (on the left and right sides of the upper part of the jib head 40 in the solid line position in FIG. 6) is alternately fitted into the locking hole 37 of the side plate 32a of the jib body 31. The jib head 40 is locked at the solid line position 40 or the alternate long and short dash line position 40A in FIG.

Reference numerals 45 and 47 denote mounting shafts and hollow mounting shafts for mounting sheaves 46 and 48 between the side plates 41, 41. The mounting shaft 45 and the hollow mounting shaft 47 are both side plates 4.
It is fixed to 1, 41 by welding or the like. Reference numeral 51 is an insertion hole for the grip fist N provided substantially at the center of both side plates 41 of the jib head 40, and 52 is a side plate 4 so that the insertion hole 51 of the grip fist N is groped.
This is a U-shaped handle for inserting and removing a jib, in which both legs are fixed to the outside of 1 by welding or the like.

B ₀ is both side plates 41, 41 of the jib head 40.
(Including the thickness of the side plate 41), B ₁ is the height of the handle 52 (including the thickness of the grip portion of the handle 52), B is the width of the handles 52, 52 on both sides, that is, the maximum of the jib head 40. The width. N ₀ is the height at which the grip fist N protrudes inward from the handle 52, that is, the operation cost for inserting and removing the jib head 40 by the grip fist N, and Na is the grip fist insertion hole 51 provided at the center of the side plate 41 of the jib head 40. As compared with a height at which the grip 41 is inserted inside the same side plate 41 and is not provided with the insertion hole 51 of the grip fist N (for example, refer to FIGS. 8 and 9), only the height Na is the handle. The height B _{1 of} 52 is configured to be low. The above structure and operation are almost the same as those in the first embodiment.

In the second embodiment, the insertion hole 5 of the grip fist N provided at the substantially central portion of the side plate 41 of the jib head 40.
1 on both left and right sides (the solid line state of FIG. 6 in which the jib head 40 is bent with respect to the jib head 30).
There is a structural feature in that a reinforcing plate 55 extending in the longitudinal direction of 0 and connecting the both side plates 41, 41 is connected by welding or the like, and the reinforcing plate 55 allows the insertion hole 51 of the side plate 41 to be inserted. The surrounding area is reinforced.

As in this second embodiment, the jib head 40
The side plates 41 of the jib head 40 can be formed by connecting and fixing the reinforcing plates 55, 55 to each other at both sides of the insertion hole 51 at the center of each side plate 41 by welding or the like.
The central portion of the grip fist N provided with the insertion hole 51 is reinforced, and the reinforcement structure thereof is simplified as compared with the reinforcement ring 53 provided in the first embodiment. And both side plates 4 of the reinforcing plate 55
The welding process to 1 and 41 is simplified, and even if there is some discrepancy in the position or shape of the insertion holes 51 and 51 provided in the both side plates 41 and 41, the same reinforcement The plate 55 can be welded to the side plate 41 without any trouble.

Incidentally, the insertion hole 51 provided in the substantially central portion of the side plate 41 of the jib head 40 of the second embodiment is formed into a crotch and is fixed to the outside by welding or the like in a U-shape.
6 can be provided not only in the longitudinal direction of the jib head 40 as shown in FIG. 6 but also in a direction orthogonal to the longitudinal direction of the jib head 40, in which case both legs of the handle 52 have the reinforcing plate 55. By welding to the same side plate 41 so as to be located outside the welded portion of
The second leg can be more firmly fixed to the side plate 52.

Further, the reinforcing plates 55 provided around the insertion hole 51 of the grip fist N at the center of the side plate 41 of the jib head 40 of the second embodiment are the same on both left and right sides of the insertion hole 51 as shown in FIG. In addition to being provided in the longitudinal direction of the side plate 41, although not shown, they may be welded to the upper and lower sides of the insertion hole 51 in FIG. 6 in a direction orthogonal to the longitudinal direction of the jib head 40 (left and right direction in FIG. 6). In this case, a strong welding structure of the leg portions of the U-shaped handle 52 arranged in the longitudinal direction of the side plate 41 to the both side plates 41 can be obtained.

Next, an embodiment of the present invention will be shown. (A) A jib 30 provided with a jib head 40 provided on the top boom 10D of the telescopic boom 10 of the wheel crane 1 so as to be bent and locked to the jib body 31 at an appropriate angle.
Was installed detachably.

(B) The jib 30 is detachably mounted on the top boom 10D of the telescopic boom 10 of the wheel crane 1, and the side plate 32 on the top of the jib body 31 of the jib 30.
One side of the jib head 40 is attached to the one side of the top part of a.
And the locking holes 42 and 43 provided on both sides of the side plate base of the jib head 40 are alternately aligned with the locking holes 37 of the side plate 32a on the top of the jib body 31 to lock. The jib head 40 is provided so as to be able to bend with respect to the jib body 31 by being locked by the pin 38.

(C) One side of the lower part of the jib head 40 is rotatably attached to one side plate 32a of the top of the jib body 31 by a mounting shaft 36, and a locking hole 43 provided on the other side of the lower part of the jib head 40. , The jib head 40 to the jib body 30
In the state in which the jib body 31 is standing upright, the jib body 31 and the jib head 40 are aligned in a straight line by aligning the locking holes 37 in the other side lower part of the side plate 32a on the top of the jib body 31 and inserting and removing the locking pins 38. It can be locked to.

(D) Around the grip fist N insertion hole 51 provided in the central portion of the side plate 41 of the jib head 40, extending in the longitudinal direction of the jib head 40 or in a direction substantially perpendicular thereto, and
A reinforcing plate 55 that exceeds the diameter of the insertion hole 51 is arranged, and the reinforcing plate 55 is fixed to the both side plates 41, 41 by welding or the like.

(Effect of the Invention) Since the present invention has the above-mentioned structure and operates, the following effects can be obtained.

(1) The sheave is supported by a hollow shaft which is fixed to the central top of the side plate of the jib head of the jib, and the hollow shaft and the top shaft are inserted and stored in the top boom. -Since the locking pin is inserted into the locking hole of the boom head of the boom for locking, a unique locking hole for storing and holding the jib in the top boom is provided. It is not necessary to install it on the side plate of the jib head,
In particular, the structure of the side plate portion is simplified.

(2) Since it is not necessary to provide the side plate of the jib head with a unique locking hole for inserting the jib into the top boom and locking it with a locking pin, the jib head of the conventional example is not provided. There is no risk of the strength of the side plate being reduced, and therefore, there is no need to increase the plate thickness of the side plate or to take measures to reinforce the locking hole around the side plate, and the structure of the jib head is simplified. At the same time, it is lightened.

(3) In the crane in which the jib is stored in the top boom of the telescopic boom, it is necessary to form an insertion hole for a locking pin for locking the jib head in the side plate as in the conventional example. Since there is no risk of reducing the strength of the same side plate as in the conventional example of the same type, it can be made smaller and lighter than the conventional example of the jib head. The size and weight of the crane can be reduced, and the freedom of design of the jib including the jib head, the top boom, and the expansion / contraction boom of the crane is improved, which is advantageous in cost.

[Brief description of drawings]

FIG. 1 is a side explanatory view of a main part of an embodiment of a jib mounting device in a crane according to the present invention.

FIG. 2 is a vertical cross-sectional explanatory view taken along the line AA of FIG.

3 is a vertical cross-sectional explanatory view taken along the line BB of FIG.

FIG. 4 is a side view of the wheel crane embodying the present invention in a state in which the telescopic boom is reduced and the wheel crane is laid down on the undercarriage, and the jib is stored in the top boom. FIG.

FIG. 5: Extending the jib head over the jib body,
It is a side surface explanatory view of the state stored in the top boom.

FIG. 6 is a side view of the essential parts of a second embodiment of the handle attaching portion structure for inserting and removing the jib from the top boom of the crane according to the present invention.

7 is a vertical cross-sectional explanatory view taken along the line CC of FIG.

FIG. 8 is a side view showing a main part of a jib attachment device in a conventional crane with a part thereof being cut away.

9 is a vertical cross-sectional explanatory view taken along the line DD of FIG.

10 is a vertical cross-sectional explanatory view taken along the line EE of FIG.

[Explanation of symbols]

 1 ... Wheel crane 10 ... Telescopic boom 10D ... Top boom 10DD ... Top boom side plate 12 ... Boom head 12A ... Boom head side plate 28 ... Boo Locking hole on side plate of head 29. Locking pin 30 .. Jib 31 .. Jib body 32 .. Side plate of jib body 32a .. Side plate on top of jib body 33 .. Locking hole at center of side plate of jib body 33a. ...... Locking hole at the center of the side plate top of the jib body 35 ...... Mounting hole at the side plate top 36 ...... Mounting shaft 37 ...... Locking hole 38 ...... Locking pin 40 ...... Jib head 41 ...... Jib head side plate 47 ...... Hollow shaft 48 ... sheave

Claims (1)

[Claims] 1. A crane in which a jib having a bendable jib head is stored in a top boom of a telescopic boom so that the jib can be retracted through a hollow shaft provided at a central top of both side plates of the jib head. With the sheave supported and the jib head raised with respect to the jib body and stored in the top boom, the hollow shaft and the top boom are
A jib mounting device in a crane, wherein a locking pin is provided to be able to be inserted into and removed from the locking hole of the frame.