JP2834411B2 - Jib overhang and storage device for wheel crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel crane such as a truck crane and a rough terrain crane, and more particularly to a jib extension and storage device for storing a jib in a boom when not in use and extending the jib to the end of the boom when in use. is there.

[0002]

2. Description of the Related Art Conventionally, when a compression column type jib is not used, it is stored on the side of a telescopic boom (side-by-side storage).
A so-called horizontal holding down swinging method is known in which after being moved from the storage position to the lower side of the boom, the boom is vertically dropped, and further swung up and stretched forward (for example, Japanese Patent Laid-Open No. 61-269).
No. 3, Japanese Utility Model Laid-Open No. 2-127693).

This method will be described with reference to FIGS.

[0004] The boom 1 includes a basic (fixed) boom 1a,
A plurality of movable booms 1b are provided, and jib support shafts 3, 3 are provided on both left and right sides of a distal end (boom head) 1c of the distal movable boom 1b of the boom 1.

On the other hand, the jib 2 is provided with bifurcated jib feet 4, 4 on both sides of the base end.

As shown by the solid lines in FIGS. 9 to 11, the jib 2 has a vertical position in which the both-side jib feet 4 and 4 are positioned vertically with the jib foot 4 facing the tip end of the boom 1 (basic boom 1a). Stored on the side and protruded by the following procedure.

As shown by a dashed line in FIG. 9, with the boom 1 (extended movable boom 1 b) extended until the boom head 1 c is positioned ahead of the jib feet 4, 4, the jib 2 is moved to a hydraulic pressure (not shown). The jib lifting means, such as a cylinder, changes the posture of the two jib feet 4 and 4 to the horizontal position, as shown by the two-dot chain line in FIGS. Process).

[0008] The boom 1 is contracted so that the two jib feet 4, 4 are engaged with the jib support shafts 3, 3, and are connected inseparably by jib holding pins (not shown).

As shown by a two-dot chain line in FIG. 12, an auxiliary rope 7 is hung on an auxiliary hook 6 attached to a tip of the auxiliary rope 5, and the other end of the rope 7 is connected to a jib provided at a tip end of the jib. Pass through the point sheave 8 and fasten to the boom-side rope stopper 9.

In this state, the auxiliary hoisting rope 5 is gradually lowered, and the jib 2 is hung as shown by a solid line in FIG.

By removing the auxiliary rope 7 from the auxiliary hook 6 and extending the boom 1 while tilting the boom 1 horizontally while the auxiliary hook 6 is locked at the tip of the jib as shown in FIG. Connect jib 2 to jib support shafts 3
The jig is pivoted around and swung up toward the front of the boom as shown by the two-dot chain line in FIG. 13 (jib swinging step).

Thereafter, a suspension rod (not shown) is hung between the boom head 1c and the jib 2 so that the jib 2
Overhang is completed.

On the other hand, the storage of the jib 2 is performed in the reverse procedure, that is, the jib storage hanging down process in which the jib 2 is hung from the overhang position. The jib pulling step of pulling the jib 2 to the holding position, and the jib storing rotation step of moving the jib 2 from the lower holding position to the storage position on the side of the boom are performed.

At the end of the jib pulling step in the jib storing operation, the first connecting pin provided on the jib side automatically fits into the pin hole provided on the jib support member on the boom side, and the jib is inserted. 2 is temporarily connected to the jib support member, and is thereafter permanently fixed by a manually attachable / detachable second connection pin.

The jib 2 is inclined at a certain angle with respect to the boom axis X in a plan view so as not to interfere with the boom hoist cylinder 10 as shown by a two-dot chain line in FIG. It is said.

In FIGS. 9 and 12, A denotes a crane body composed of a lower traveling body 11 and an upper revolving superstructure 12, and 12a.
Is a cabin (operating cab) provided on the upper rotating body 12 side.

According to this method, there is no need to extend the jib to the side of the boom to secure a large space for storage, and since the jib 2 does not protrude below the boom 1 in the stored state, the visibility at the time of crane operation and traveling is reduced. Are good.

[0018]

However, heretofore, the following problems have conventionally occurred in the horizontal holding down swinging system as described above.

In the hanging step at the time of extending the jib shown in FIG.
First, (a) remove the second connecting pin in the horizontal state of the boom (in this state, the jib 2 is supported only by the first pin connecting pin of the automatic detachable type), (b) raise the boom 1, (c) Next, the operation of detaching the first connecting pin from the pin hole on the jib support member side is performed by slightly extending the boom 1 and moving the jib 2 forward.

In this case, there is no problem if the auxiliary rope 5 and the auxiliary rope 7 are used as described above. However, in practice, since the rope hanging work is complicated, the jib is used without using the ropes 5 and 7. There is a case where a method of moving at a stroke without giving a braking force from the holding position under the two-dot chain line to the hanging position of the solid line by its own weight may be adopted.

In this case, if the boom angle θ1 is less than a certain angle (50 ° according to the test of the present inventor), the jib 2
Has collided with the crane main body A (especially the lower traveling body 11), and a trouble has occurred in which both are damaged.

As a countermeasure, it is conceivable to configure the control system such that the extension operation of the boom 1 is completely prohibited at the boom angle at which the collision occurs (hereinafter, referred to as the danger angle) when the jib is extended.

However, in this case, (A) In the jib raising step of extending the boom 1 while tilting it as shown in FIG. 13, when the boom angle reaches the dangerous angle, the extending operation of the boom 1 is automatically stopped. (B) In the rotation step at the time of extending the jib, the operation of slightly extending the boom 1 in order to avoid interference between the jib feet 4 and 4 and the boom head 1c cannot be performed as shown by the dashed line in FIG. Evils occur.

Accordingly, the present invention provides a jib extension and storage device of a wheel type crane which can safely perform a hanging operation at the time of extension of the jib without causing such adverse effects.

[0025]

SUMMARY OF THE INVENTION According to the present invention, a jib is protruded forward from a front end of a boom in a state where a base end of the jib is detachably connected to a front end of a telescopic boom. A jib hanging process of hanging down with the fulcrum as a fulcrum, and a wheel configured to be retracted to the boom via a jib pulling process of pulling the boom underneath and setting it at the lower holding position, and then extending over by a reverse operation. The type crane has the following configuration.

(I) The boom is provided with a jib support member for supporting the jib at the lower holding position.

(II) As means for detachably connecting the jib and the jib support member at the lower holding position, the jib is automatically straddled over the jib and the jib supporting member when the jib is set at the lower holding position. A first connecting means to be inserted, and a manually attachable / detachable second connecting means for detachably connecting the jib and the jib support member at a position shifted in the jib length direction with respect to a jib support point by the first connecting means. And having.

(III) A boom angle sensor for detecting the elevation angle of the boom, a first pin sensor for detecting the connection state of the first connection means, and a second pin sensor for detecting the connection state of the second connection means. Is provided.

(IV) control means for inputting detection signals of these sensors, wherein the control means in the jib overhang / retract mode, based on each sensor signal, that the boom angle is smaller than the set angle; It is configured to output a signal for prohibiting the boom extension operation only in a state where three conditions that the first connection unit is in the connection state and the second connection unit is not in the connection state are met. That

[0030]

According to the above construction, only when the first connecting means is ON (connected state) and the second connecting means is OFF (non-connected state), that is, only when the hanging operation is performed when the jib is extended, the boom can be used. When the angle is less than the set angle (dangerous angle), the extension operation of the boom is prohibited.

Therefore, under other circumstances, even if the boom angle is smaller than the set angle, the boom extension operation can be performed. Therefore, in the jib overhanging operation, either of the jib swing-up operation shown in FIG. 13 in which the boom is extended while tilting the boom and the operation of slightly extending the boom to avoid interference between the jib foot and the boom head before performing the rotation operation at the time of extending the jib. Is also possible.

That is, the jib extension operation can be safely performed without causing any adverse effect.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

In the following embodiment, FIGS.
The same components as those of the conventional device shown in FIG.

The jib 2 is fixed to the boom 1 by a pin-removable tip side fixing mechanism 13 in a horizontal holding state shown by phantom lines in FIGS. 1 and 2, and a jib center of gravity O (FIG. ) Is supported by the boom 1 by the intermediate support mechanism 14.

As shown in FIGS. 4 to 6, the intermediate support mechanism 14 includes a boom-side bracket 1 fixed to the boom 1.
5, an intermediate frame 16 attached to the bracket 15, a jib support frame (jib support member) 17 attached to the intermediate frame 16, and a jib side bracket 18 attached to the jib 2. .

The boom-side bracket 15 is provided with vertical support shafts 15a, 15a on both upper and lower sides in a horizontal state of the boom.
a, 15a (second axis C = shown in FIG. 5).

A jib turning cylinder 19 as jib turning means for turning the jib 2 around the second axis C is provided between the intermediate frame 16 and the boom 1.

On the other hand, the jib support frame 17 has an axis 20 (first axis B) that is parallel to the boom axis (horizontal in the boom horizontal state) in a side view with respect to the intermediate frame 16.
5 (shown in FIG. 4), and a jib elevating cylinder 21 as a jib elevating means provided between the frames 16 and 17 as shown in phantom lines in FIG. It can rotate between the position shown by the solid line (the jib lower position).

The jib support frame 17 is engaged with the jib bracket 18 and has an automatic detachable first connecting pin 22 as a connecting means provided on the jib 2 side, and a second connecting pin manually detachable. 26 and the bracket 18.

The first connecting pin 22 is slidably supported in the front-rear direction (jib length direction) by the pin guide members 23 and 24 of the jib 2. The jib support frame 17 and the jib-side bracket 18 are connected by fitting into the pin holes 17a of the jib support frame 17 from above.

The tip portion 22a of the first connecting pin 22
As shown in FIG. 4, is formed to be sharp so as to automatically fit into the pin hole 17a at the end of the jib pulling process in the jib storing operation.

The second connecting pin 26 is, as shown in FIG.
The first shaft portion 26a and the longer second shaft portion 26b are formed in a hairpin shape integrally connected by a plate 26c and a handle 26d.

The first shaft portion 26a of the second connecting pin 26
Is inserted across the jib support frame 17 and the jib side bracket 18 at a position shifted to the jib tip side with respect to the connection point by the first connection pin 22 (D indicates the amount of shift in FIG. 6). .

As a result, the jib 2 is supported at two locations in the longitudinal direction by the first and second connecting pins 22 and 26, so that the jib 2 is held around the first axis B in the horizontal holding position and the lower position. In the step of turning between the two positions, there is no possibility that the jib 2 swings up and down around the intermediate support point as in the case where the jib 2 is supported at only one point by only the first connecting pin 22. Can be easily performed.

On the other hand, the second shaft portion 26b is loosely inserted across the jib support frame 17 and the jib side bracket 18, and the retaining pin 27
Is plugged in.

As shown in FIG. 5, the jib-side bracket 18 and the intermediate frame 16 have flanges 2 respectively.
8 and 29 are provided.
8 and 29 are connected by the storage lock pin 30.

Further, as shown in FIGS. 2 and 3, a stopper 31 projects downward at a position on the lower surface of the end of the boom 1 opposite to the jib storage side, and the jib 2 is held at the jib lower holding position as described later. The base end side is positioned by hitting the stopper 31.

The jib 2 is extended from the horizontal holding state shown by the imaginary line in FIGS. 1 and 2 by the following procedure.

The fixing of the jib tip side by the jib tip side fixing mechanism 13 is released, and the storage lock pin 29 of the intermediate support mechanism 14 is removed.

In this state, the jib 2 is connected to the boom 1 at two points in the longitudinal direction of the intermediate portion by the first and second connecting pins 22 and 26 of the intermediate support mechanism 14.

[0052] Jib feet 4, 4 and boom head 1c
After slightly extending the boom 1 (about 1 m) in order to avoid interference, the jib 2 is rotated about the first axis B by extending the jib elevating cylinder 21 as shown in FIG. Move to the lower position located on the lower side of the boom in the placing posture.

In this lower position, the jib 2 is in a state where the both-side jib feet 4, 4 are displaced laterally from the both-side jib support shafts 3, 3 as shown in FIG.

By extending the jib rotation cylinder 19, the jib 2 is moved as shown by the phantom line in FIGS. 3 and 6.
Is rotated about the second axis C, and the jib feet 4, 4 on both sides are rotated.
Is set at the lower holding position facing the jib support shafts 3, 3 on both sides.

At this time, the base end side of the jib 2 hits the stopper 31 of the boom 1 and is automatically positioned at the lower holding position.

Also, in this case, since the jib support point of the intermediate support mechanism 14 is set closer to the jib base end than the jib center of gravity O, the jib 2 is raised forward at the lower position and the lower holding position, so that the jib 2 is raised forward. The base end is in contact with the lower surface of the boom.

Therefore, there is no danger that the jib 2 moves on the seesaw at both positions and collides with the lower surface of the boom, and a stable rotation operation can be performed.

Also, this enables the jib feet 4, 4 on both sides.
The upper and lower positions of the jib feet 4, 4 are determined by the stopper 31 at the jib holding position, so that the positioning of the both jib feet 4, 4 with respect to the jib support shafts 3, 3 can be performed easily and accurately. Can be done.

The boom 1 is fully contracted so that the both-side jib feet 4 and 4 are engaged with the both-side jib support shafts 3 and 3 and these are inseparably connected by jib holding pins (not shown).

The second connecting pin 2 of the intermediate support mechanism 14
Remove 6. In this state, the jib 2 is connected to the jib support frame 17 only by the first connection pin 22.

Next, the boom 1 is raised (for example, 60 °
The boom 1 is slightly extended with the jib 2 supported by the auxiliary rope 5, auxiliary hook 6, and auxiliary rope 7 shown in FIG.

Thus, the jib 2 is moved in the direction of the boom tip, and the first connecting pin 22 is detached from the jib support frame 17.

Thereafter, the auxiliary hoisting rope 5 is gradually lowered, and thereafter, the jib 2 is hung down as shown by a solid line in FIG.
Swing forward like 3 (jib swinging process).

On the other hand, the storage of the jib 2 can be basically performed by the reverse procedure and operation.

To explain only the essential points, the jib 2 is dropped from the overhang position shown by the two-dot chain line in FIG. 13 as shown by the solid line in FIG. 12 (the hanging step when the jib is stored), and further shown by the two-dot chain line in FIG. Thus, the jib support frame 17 is engaged with the jib-side bracket 18 and the first connecting pin 22 is automatically inserted into the pin hole 17a.

Next, after the boom 1 is tilted horizontally, the jib holding pins on both sides are pulled out to release the fixing of the both jib feet 4 and 4 of the jib 2 and the both jib support shafts 3 and 3, and the second connecting pin 26 is set. I do.

In this state, the boom 1 is extended to separate the two jib feet 4 and 4 from the two jib support shafts 3 and 3.

Further, after the jib rotation cylinder 19 is reduced to return the jib 2 from the lower holding position to the lower position, the jib elevating cylinder 21 is reduced to set the jib 2 to the horizontal holding position, and the distal end side fixing mechanism is set. 13, the jib 3 is finally fixed at this storage position.

As in this embodiment, the jib 2 is not moved from the storage position to the holding position at once, as in the conventional case, but is temporarily moved to a lower position located on the lower surface of the boom in a horizontal position. After that, the tilt angle β (shown in FIG. 1) of the jib 2 in the horizontal holding state is made smaller than the conventional tilt angle α (shown in FIG. 10) by adopting a configuration in which the jib 2 is rotated to the lower holding position. Can be.

Accordingly, the amount of protrusion A2 of the jib tip toward the boom side can be reduced as compared with the conventional case (A1 in FIG. 10), so that the vehicle width can be reduced or the jib can be maintained at the same vehicle width as the conventional one. 2 can be lengthened.

Next, a configuration and an operation for preventing a trouble in the hanging process at the time of extending the jib shown in FIG. 12 will be described.

As a sensor, a boom angle sensor 32 (shown in FIG. 2) for detecting the elevation angle θ1 of the boom 1 and a first pin sensor (for example, a proximity switch) for detecting the set state of the first connecting pin 22 in the intermediate support mechanism 14 A second pin sensor (for example, a limit switch is used) 34 for detecting the set state of the second connection pin 26 is provided.

The detection signals from the sensors 32, 33, and 34 are input to the arithmetic and control unit 36 of the controller 35 shown in FIG. As the controller 35, a controller of an overload prevention device (a so-called moment limiter) which is provided as a standard feature in a wheel type crane is used.

The controller 35 is provided with a mode selection switch 37 for selecting a work mode from a plurality of types (boom work mode, jib work mode, traveling mode, jib extension / storage mode, etc.). Sometimes the jib overhang / storage mode is selected.

The arithmetic control unit 36 includes the auxiliary rope 5 and the auxiliary rope 7
The lower limit of the boom angle (for example, 50 °, hereinafter referred to as “safety boom angle”) θ0 at which there is no risk of collision between the jib 2 and the crane main body A even when the method of hanging the jib 2 by its own weight without using the method is adopted. (I) that the boom angle θ1 detected by the boom angle sensor 32 is less than the safety boom angle θ0; (II) that the first connecting pin 22 is set (first
(III) The boom extension stop valve 3 only when the three conditions of (III) that the second connecting pin 26 is not set (the second pin sensor 34 is off) are satisfied.
8, an operation signal (a signal for inhibiting the boom extension operation) is output.

This will be described with reference to the flowchart of FIG.

At the start of the control, it is determined whether or not the overhang / storage mode has been selected (step S1), and YES
In the case of (2), it is determined based on the signal from the second pin sensor 34 whether or not the second connection pin 26 is in the non-set state (step S2).

Here, YES, that is, the second connecting pin 26
Is removed, it is determined in step S3 whether or not the first connection pin 22 is set based on a signal from the first pin sensor 33. If the first connection pin 22 is set, the process proceeds to step S4. It is determined whether the boom angle θ1 is less than the safe angle θ0.

If θ1 <θ0, it is determined whether a boom extension operation has been performed (step S5).
If so, a boom extension stop signal is output to the boom extension stop valve 38.

On the other hand, if NO in any of steps S1 to S5, no boom extension stop signal is output (step S7).

The boom extension stop valve 38 is provided in the operation circuit of the boom telescopic cylinder, and the operation of the valve 38 stops the supply of oil to the cylinder extension side oil chamber and stops the extension operation of the cylinder.

Thus, there is no possibility that the jib 2 collides with the crane main body A in the hanging process at the time of extending the jib, and the same operation can be performed safely.

Here, of the above three conditions, (II) (II
I) is a condition for entering the hanging operation when the jib is extended. Only under this condition, the extension operation of the boom is stopped when the detected boom angle θ1 is less than the safety boom angle θ0 (dangerous angle).

Therefore, under other circumstances, even if the boom angle is less than the safe boom angle θ0, the boom extension operation can be performed.

For this reason, in the jib overhanging operation, (a) as shown in FIG. 13, the jib swing-up operation for extending the boom 1 while tilting it down, and (b) as shown in FIG. In order to avoid interference between the jib feet 4 and 4 and the boom head 1c, any operation of slightly extending the boom 1 can be performed.

That is, as in the case where only the above condition (I) is set as the boom extension operation prohibition condition, the above (a) and (b)
The disadvantage that the operation cannot be performed does not occur.

Other Embodiments (1) As means for inhibiting the extension operation of the boom 1 based on the boom extension inhibition signal from the arithmetic and control unit 36 of the controller 35, the boom extension stop valve 37 as in the above embodiment is used.
Instead of the means for operating the boom, an extension lock mechanism operated by an electromagnet may be provided on the boom, and the extension operation of the boom may be mechanically locked by the mechanism.

Alternatively, a similar lock mechanism may be provided at the operation portion of the control valve for extending and retracting the boom so that the operation of the control valve for extension of the boom cannot be performed.

(2) In the above embodiment, when the jib is extended, the jib 2 is temporarily moved from the horizontal holding position to the lower position, and then is set to the lower holding position. The present invention can be applied to the case where the second embodiment is configured to move from the horizontal holding position to the lower holding position at once.

[0090]

As described above, according to the present invention, it is assumed that the jib is connected to the jib support member at the lower holding position by the first connecting means of automatic detachable type and the second connecting means of manual detachable type. When the boom angle is less than the set angle (dangerous angle) only in a situation where the first coupling means is in the coupled state and the second coupling means is in the non-coupled state, that is, under the situation where the hanging operation is performed at the time of extending the jib Since the boom extension operation is prohibited, the boom extension operation can be performed in other situations even if the boom angle is smaller than the set angle.

Therefore, in the jib extension operation, both the jib swing-up operation of extending the boom while tilting it and the operation of slightly extending the boom before performing the rotation operation at the time of the jib extension can be performed.

In other words, the jib extension operation can be safely performed without causing any adverse effects.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a jib retracted state according to an embodiment of the present invention.

FIG. 2 is a schematic side view of a state where the jib has been moved from the state of FIG. 1 to a lower position.

FIG. 3 is a schematic plan view of the state shown in FIG. 2;

FIG. 4 is a partially enlarged view of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is an enlarged sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a block diagram of a control system.

FIG. 8 is a flowchart for explaining the operation of the control system.

FIG. 9 is a schematic side view of a jib retracted state for explaining a conventional technique.

FIG. 10 is a schematic plan view of the same.

FIG. 11 is an enlarged sectional view taken along line XI-XI of FIG. 9;

FIG. 12 is a schematic side view of a state in which the jib is suspended as one step of the jib overhang.

FIG. 13 is a schematic side view of the jib being swung up from the state of FIG. 12 toward the overhang position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boom 3, 3 Jib support shaft of boom 2 Jib 4, 4 Jib foot on both sides of jib 14 Intermediate support mechanism 17 supporting the middle part of jib 17 Jib support frame (jib support member) 17a Pin hole 22 of connection means 1 connection pin 26 second connection pin 32 boom angle sensor 33 1st pin sensor 34 2nd pin sensor 35 controller (control means) 36 operation control unit of controller 37 mode selection switch 38 boom extension stop valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-114294 (JP, A) JP-A-5-155558 (JP, A) Full-scale operation Sho-59-179885 (JP, U) Real-time operation Sho-62 144294 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B66C 23/00-23/94

Claims (1)

(57) [Claims] 1. A boom distal end in which the base end of a jib is telescopic.
With the jib detachably connected to the front of the boom tip
The jib and drop it using the connection point as a fulcrum.
Jib hanging process, after this hanging, pull down to the bottom of the boom
Boom through jib pulling process to set to lower holding position
It is configured to store and overhang by the reverse operation
Wheel crane equipped with the following configuration
Jib overhang and storage equipment for wheel crane
Place. (I) A jib that supports the jib at the lower holding position on the boom
A support member is provided. (II) Attach the jib and the jib support member at the lower holding position.
Set the jib in the lower holding position as a means of detachable connection.
Automatically straddles the jib and jib support when
First connecting means to be inserted;
Jib and jib at a position shifted in the jib length direction from the jib support point.
Manually detachable second link that detachably connects the valve support member
And a tying means. (III) A boom angle sensor for detecting the boom undulation angle.
Sensor and a first pin for detecting a connection state of the first connection means.
And a second sensor for detecting a connection state of the second connection means.
A two-pin sensor is provided. (IV) Control means to which detection signals of these sensors are input
The control means is in the jib overhang / retract mode.
And the boom angle is set to the set angle based on each sensor signal.
Less than the first connecting means is in a connected state
That the second connecting means is not in the connected state;
Prohibits boom extension operation only when two conditions are met
Output signals.