JPH075110Y2 - Device for holding and holding auxiliary jib in wheeled crane - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a storage / holding device for an auxiliary jib that holds the auxiliary jib at a storage position on the side of a boom in a wheel crane such as a truck crane and a rough terrain crane. is there.

[Conventional technology]

Conventionally, a compression column type auxiliary jib (hereinafter simply referred to as a jib) configured like a ladder is laterally held and stored on one lateral side of the boom when not in use in a vertical position with the direction of the jib thickness direction facing left and right. In a so-called jib twist type wheel crane in which the jib is hung from a position and then twisted (see, for example, Japanese Patent Laid-Open No. 62-46898), the jib is pinned to the boom at several points in the longitudinal direction and fixed in the retracted state. Is common.

[Problems to be solved by the invention] However, due to a mistake made by a worker during the retracting work, a pin for fixing the jib in the forward direction may be forgotten, or the pin may be pulled out due to an error in the procedure during the overhanging or retracting work. It may occur.

If such a state in which the function of fixing the jib to the front is lost (hereinafter referred to as the jib non-fixation state) occurs, the jib will move forward when the boom is set to the front lower position or the traveling is suddenly stopped. There was a risk of slipping and falling off.

Therefore, the present invention provides a storage and holding device for an auxiliary jib in a wheeled crane, which can prevent the jib from sliding forward and falling and can be securely held in a storage position even if the jib is not fixed. It is a thing.

[Means for Solving the Problems]

The present invention connects the base end of a jib vertically placed on the side of the boom to the tip of the boom, suspends the jib with this connecting point as a fulcrum, and twists the boom in this suspended state. On the other hand, the jib drooping process and the jib pulling process are performed on the side of the boom where the jib is stored, while it is extended through the tip end, and on the contrary, the twisting process and the pulling process of pulling it from the drooping position to the retracted position are stored. In a wheel-type crane provided with an engaging rail that engages with an engaging piece on the jib side in the approaching step, the engaging rail is abutted against the auxiliary jib from the front in the retracted state of the auxiliary jib to prevent the jib from moving forward. A stopper member is provided.

[Action]

With this configuration, since the stopper member prevents the jib from moving forward in the jib retracted state, the jib is reliably prevented from sliding forward even if the jib unfixed state occurs.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

First, the basic structure for overhanging and storing the jib in this wheel type crane will be described.

The telescopic boom 1 is telescopically configured by the basic boom 1a, the intermediate boom 1b, and the tip boom 1c.

In addition, although the intermediate boom 1b is generally provided in a plurality of stages,
In order to make the explanation easier to understand, the middle boom 1b is set to 1
The case of a step is shown.

In this telescopic boom 1, jib mounting shafts 11 and 12 (right side is shown in Fig. 6) 11 and 12 are horizontally projected respectively on the left and right ends of the tip boom 1c, and the jib 2 at the tip of the basic boom 1a is provided. A publicly known jib guide 3 having a horizontal groove portion 31 and a slanting groove portion 32 which descends to the front is provided on the left side surface in which is stored.

An engagement rail 4 is provided on the left side surface of the tip of the intermediate boom 1b.

The engagement rail 4 is a frame member having a U-shaped cross section, and is formed in an arc shape centered on the left jib mounting shaft 11 in the fully contracted state of the boom, and its front portion projects toward the tip side of the tip boom 1c. It is installed in the state.

The jib 2 has a plurality of connecting bars 2c between the main girders 2a and 2b on the left and right sides.
It is constructed in the shape of a conical ladder with ...

This jib 2 has both left and right sides of the base end, that is, both main girders 2
Bifurcated jib feet 21, 22 are provided at the base end of a, 2b,
When the jib is used, as shown in FIGS. 5 and 6, the jib feet 21 and 22 on both sides are extended to the tip of the boom while being engaged and connected to the jib mounting shafts 11 and 12, respectively. As shown in FIG. 9 and the like, the left jib foot 21 is pulled down and stored on the left side surface of the boom in a vertical posture with the right jib foot 22 positioned on the upper side.

A box-shaped bracket 23 is fixed to the lower surface of the base end portion of the lower main girder 2a in the stored state in the jib 2, and the bracket 23
A bifurcated connector 5 is provided via a rod 51.

The rod 51 is rotatable about the rod axis x and slides on the coaxial center x on the bracket 23 in a state where the rod 51 is substantially parallel to the lower main girder 2a at a position displaced downward from the lower main girder 2a. It is supported freely.

Thereby, the connector 5 is configured to be rotatable around the rod axis x and slide on the coaxial axis x.

Further, a thrust plate 52 is attached to the end of the rod 51 on the side opposite to the connecting tool 5, and the thrust plate 52 is in contact with the tip surface of the bracket 23 in the state shown in FIG.
The rod 51, that is, the connector 5 is in an advanced state in which it is maximally projected in the base end direction of the jib. In this advanced state, the connector 5 projects from the lower (left) jib foot 21 toward the jib proximal end,
In this state, the connector 5 can be engaged with the left jib mounting shaft 11.

On the other hand, a guide roller 24 is projectingly provided on the upper surface of the base of the upper main girder 2b in the retracted state of the jib 2.
And the jib guide 3 of the boom 2 allow the jib 2 to move from the retracted position shown in FIGS. 1 and 9 to the hanging position shown in FIG. 8 when the jib is extended, and vice versa when the jib is retracted.

In addition, the right jib foot 22 located on the upper side when the jib is stored
In addition, a known engagement piece 25 that engages with the engagement rail 4 of the boom 1
Is projected.

Next, the jib storage procedure will be described.

As shown in FIGS. 5 and 6, the jib 2 has a boom tip with the left jib foot 21 and the connecting tool 5 engaged and connected to the left jib mounting shaft 11 and the right jib foot 22 to the right jib mounting shaft 12, respectively, as shown in FIGS. Overhang. Reference symbol S denotes a suspension rod that supports the jib 2 in this jib extended state.

(B) Tilt the boom 1 almost horizontally, and lock the auxiliary hook F attached to the end of the auxiliary winding rope W at the jib tip to make the jib 2
The suspension rod S is removed in the state shown in FIGS.

In addition, the pin fixing of the left and right jib feet 21,22 to the jib mounting shafts 11,12 is released, and then the boom 3 is raised.

Next, after loosening the auxiliary winding rope W to hang down the jib 2 as shown in FIG. 7 and removing the auxiliary hook F from the tip of the jib, the jib 2 is stored around the rod axis x of the connector 5. Twist about 270 ° in the direction (arrow A in FIG. 7).

At this time, the engaging piece 25 of the jib 2 is connected to the engaging rail 4 of the boom 1.
Then, the boom 3 is raised from this state to the state shown in FIG.

In this state, the guide roller 24 faces the entrance of the jib guide 3, and then the boom 1 is contracted so that the guide roller 24 enters the jib guide 3 and moves from the inclined groove portion 32 to the horizontal groove portion 31.

As a result, the jib 4 is automatically pulled toward the left side surface of the boom with the connection point between the connecting tool 5 and the left jib mounting shaft 11 as a fulcrum, and the storage state shown in FIGS. 9 and 1 to 4 is obtained.

Also, at this jib pulling stage, the engaging piece 25 of the jib 2
Is engaged with the engaging rail 4 of the boom 1
This engagement guide action prevents rotation of the jib 2 around the rod axis during pulling of the jib, that is, reverse rotation (overturn) in the extension direction.

At this retracted position, the jib 2 has its middle portion and tip portion fixed to the left side surface of the basic boom 1a with a pin (not shown).

After the jib is stored, the connector 5 is removed from the left jib mounting shaft 11 so as not to interfere with the work of the boom alone.

Further, when the jib is retracted, the engaging piece 25 of the jib 2 is
It is in a state of being disengaged forward from the engagement rail 4 of.

On the other hand, the extension of the jib 2 is performed by the procedure reverse to the above.

According to the above-mentioned jib overhanging and retracting configuration, in the jib retracted state shown in FIGS. 1 and 9, the jib lower main girder 2a is positioned a distance d above the rod 51 which is the twist center axis. Compared with the case where the lower jib foot axis is set as the twist center, the entire jib is stored upward by the distance d.

That is, the jib 2 can be automatically stored in the upper position where it hardly projects below the boom, and it is not necessary to pull up the jib 2 again to the upper position after the jib 2 is pulled, and a good front view can be secured.

By the way, the conventional left side jib foot 21 is directly engaged with and connected to the left side jib mounting shaft 11, and the jib 2 is formed with this connecting point as a fulcrum.
In the case of the method of twist rotation, since the left jib foot 21 is engaged with the left jib mounting shaft 11 in the jib retracted state,
The jib mounting shaft 11 prevents the jib 2 from sliding forward even when the jib is unfixed due to an error in the procedure of the jib overhanging, storing procedure, or forgetting to insert the fixing pin.

However, according to the above configuration in which the connecting tool 5 is provided separately from the left jib foot 21 to store the jib 2 in the highest position, the left jib foot 21 is located above the left jib mounting shaft 11 when the jib is stored. Moreover, since the connecting tool 5 is removed from the jib mounting shaft 11, there is a problem that the jib 2 is likely to slide forward and fall when the jib unfixed state occurs.

Therefore, as a measure against this point, the engagement rail 4 is provided with a stopper 6.

The stopper 6 is fitted on the right side (upper side) jib foot 22 as shown in the figure in a state where the jib is stored, and is attached to the side surface of the front end portion of the engaging rail 4 via an angled mounting plate 61 so that the upper portion of the rail is provided. It is attached so that it protrudes into the.

Therefore, when the jib is stored, the stopper 6 prevents the right jib foot 22, that is, the entire jib from moving forward, so that even if the jib is not fixed, the jib 2 can be reliably prevented from sliding forward and falling off. Will be done.

Further, since the stopper 6 is provided on the engaging rail 4, the stopper 6 is independent of the rail 4 and the boom 1 (intermediate boom
Compared to mounting directly on 1b), the stopper 6 is smaller and lighter, and its mounting is easier.

Further, the right side jib foot 22 is restricted in the left-right direction by the stopper 6, so that the jib foot 22 is kept in the retracted position.
Moves in a direction away from the side surface of the boom and the planar position of the engaging piece 25 is disengaged from the engaging rail 4, and the engaging piece 25 is attached to the engaging rail 4 when the jib 2 is suspended from the retracted position at the time of extension. There is no risk that the jib 2 will rotate around the rod axis x during the hanging process without being fitted.

By the way, in the above-described embodiment, the jib twist method is used as the jib storing method in which the jib is likely to slide due to the occurrence of the unfixed state of the jib, and the axial center x deviated from the left main girder 2a of the jib is x.
An example of a crane that uses a twist rotation method around it has been taken as an example. Since the jib foot 21 may be disengaged from the left jib mounting shaft 11 to cause the jib 2 to slide forward, the present invention can be applied to such a crane.

[Effect of device]

As described above, according to the present invention, in the wheel type crane which adopts the jib twist system and stores the jib vertically, the jib is prevented from falling during the jib hanging process when the jib is extended and the jib pulling process when the jib is retracted. For this reason, a stopper member is provided on the engaging rail provided on the side surface of the boom to prevent the jib from moving forward when the jib is retracted. When the jib unfixed state in which the jib is not fixed in all directions at the storage position occurs due to forgetting to insert the jib, the stopper can reliably prevent the jib from sliding forward.

Further, since the stopper member is provided on the engaging rail, the stopper member is smaller and lighter in weight, and the mounting thereof is easier than when the stopper member is directly attached to the boom independently of the rail.

[Brief description of drawings]

FIG. 1 is a partial side view of a crane in which a storage and holding device according to an embodiment of the present invention is installed, in a state where the jib is stored,
1 is a partially enlarged view of FIG. 1, FIG. 3 is a plan view of the same, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. 5 is a side view of a jib projecting state for explaining a jib storing procedure. Figures and 6 are plan views of the same.
7 is a side view of the jib hanging state, FIG. 8 is a side view of the jib further twisted, and FIG. 9 is a side view of the jib stored state. 1 ... Boom, 11,12 ... Jib mounting shaft, 2 ... Auxiliary jib, 21,22 ... Jib foot as connecting part, 4 ... Engaging rail, 25 ... Engaging piece, 6 ... Stopper.

Claims (1)

[Scope of utility model registration request] 1. A step of connecting a base end portion of a jib vertically placed and stored on a side surface of a boom to a tip end portion of the boom, suspending the jib with the connecting point as a fulcrum, and twisting the jib in the suspended state. On the other hand, the jib drooping process and the jib hanging process are performed on the side of the boom where the jib is stored, while the boom is extended to the tip of the boom, and conversely, the twisting process and the pulling process of pulling from the hanging position to the retracted position are performed. In a wheel type crane provided with an engaging rail that engages with an engaging piece on the jib side in the pulling process, the engaging rail is brought into contact with the auxiliary jib from the front in the retracted state of the auxiliary jib to move the jib forward. A storage / holding device for an auxiliary jib in a wheel-type crane, characterized in that a stopper member for blocking is provided.