JPH0328069Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a jib extension system for wheel cranes such as truck cranes and rough terrain cranes, in which a compression column type jib is extended and retracted using the so-called jib twist method. , relating to storage devices.

[Conventional technology]

An example of the basic configuration of a conventional device for extending and storing a jib using the above-mentioned jib twist method and a procedure for storing the jib will be briefly explained with reference to FIGS. 21 to 24.

(A) First and second on both sides of the tip of boom 1.
Both jib mounting shafts 11 and 12 are provided protrudingly.

(B) Both sides of the base end of the jib 2 (left and right as seen from the operator's cab when the jib is extended; the same is true for the left and right directions below), that is, the base ends of both the first and second main girders 2a and 2b of the jib. , both bifurcated first and second jib feet 21 and 22 which can be engaged with and disengaged from the jib mounting shafts 11 and 12 are provided.

(C) Of the jib feet 21 and 22 on both sides, the first jib foot 21 is configured as a movable jib foot that can rotate around its axis, and the second jib foot is configured as a fixed jib foot that cannot rotate.

(D) When using the jib 2, as shown in Figs. 21 and 22, the first jib foot 21 is connected to the second jib mounting shaft 11.
, the second jib foot 22 is attached to the second jib mounting shaft 12.
Extend it from the tip of the boom with each of them engaged. In Fig. 21, S indicates jib 2 in this extended state.
It is a suspension rod that supports.

Jib storage procedure (a) With the suspension rod S removed and only the first jib foot 21 engaged and connected to the first jib mounting shaft 11, move the jib 2 below the tip of the boom as shown by the imaginary line in Figure 21. hang. W is an auxiliary wire rope that supports the jib 2 at this time, and its end is fixed near the tip of the jib 2.

(b) After removing the end of the auxiliary wire rope W from the jib tip, attach the jib 2 as shown in Figure 23.
270° around the axis of the first jib foot 21.

(c) Pass the auxiliary winding wire rope W through the guide sheep 23 provided at the tip of the jib, and with the end fixed to the boom base, wind up the auxiliary winding wire rope W, as shown in Fig. 24. The jib 2 is attached to the boom 1 using the first jib mounting shaft 11 as a fulcrum.
Pull it to the left side of the

(iv) After this pulling, the jib 2 is fixed at the base and tip using known jib fixing means (not shown).

In this way, the jib 2 is stored vertically on the left side of the boom 1 in a so-called sideways position.

[The problem that the idea aims to solve]

However, according to the conventional device, as described above, the jib 2 is pulled and stored on the left side of the boom using the first jib foot 21 provided at the base end of the first main girder 2a of the jib 2 as a fulcrum. In the retracted state, most of the first main girder 2a of the jib 2 (shown with diagonal lines in FIG. 24) protrudes below the boom.

For this reason, this jib protrusion reduces the forward visibility from the driver's cab while the crane is moving, especially in the case of rough terrain cranes where the boom overhangs in front of the operator's cab is large and the forward visibility is poor. The protruding part of the jib was an obstacle to running.

On the other hand, as shown in Japanese Patent Application Laid-open No. 61-86386, after the jib is pulled to the side of the boom, the jib and boom are connected via a pulley, and the jib is moved downwards by the boom extension. There is a known device that is pulled up to an upper position that does not protrude as much as possible.

However, with this configuration, an extra jib raising process is required at the stowed position (the opposite lowering process when the jib is extended), which makes the jib stowing and extending work troublesome, and has the disadvantage of deteriorating work efficiency. .

Therefore, the present invention has developed a jib extension and storage device for a crane that can set the jib in the upper position only by pulling the jib, without requiring the lifting and lowering operations of the jib in the stowed position as described above. This is what we provide.

[Means to solve the problem]

In this invention, there is a first
A jib mounting shaft and a second jib mounting shaft are provided on the other side, while first and second jib feet are provided at the base end of the jib to be detachably connected to both of the jib mounting shafts. The jib is stored on the side of the boom in a vertical position with the first jib foot on the lower side and the second jib foot on the upper side, and the jib goes through the steps of hanging, twisting, and pulling up, and then the first jib foot is attached to the first jib mounting axis. , the second jib foot is
In a crane that extends from the tip of the boom while connected to each jib mounting shaft, and stores it in the reverse procedure, the lower side of the base end of the jib when the jib is stored is attached to the first jib mounting shaft. a coupling device that is detachable from the jib and rotatably engaged about the attachment axis, is attached rotatably about an axis in the length direction of the jib that is shifted downward from the lower side of the jib when the jib is stored, and jib moving means for moving the jib from a storage position to a hanging position using this connection point as a fulcrum with the connecting tool connected to the first jib mounting shaft when the jib is extended, and vice versa when retracting the jib; It is equipped with the following.

[Effect]

With this configuration, when the jib is stored, the lower side of the jib is drawn to the side surface of the boom in a state located above the jib attachment shaft. That is, the jib is automatically set to the upper position only by the jib pulling operation without requiring any operation to raise or lower the jib in the storage position.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 20.

Basic Embodiment (See FIGS. 1 to 11) The boom 3 is usually composed of a basic boom and a plurality of movable booms. However, in order to make the explanation easier to understand, here, a case is shown in which the boom 3 is constructed as a one-stage telescoping type consisting of only a basic boom 3A and a single-stage movable boom 3B.

The jib 4 has a tapered ladder shape with a plurality of connecting bars 4c attached between the first and second main girders 4a, 4b.

First and second jib attachment shafts 31 and 32 are horizontally protruded from the boom 3 on both left and right sides of the distal end of the movable boom 3B. Of these, the first jib mounting shaft 31 on the left side has an auxiliary mounting portion 31b integrally extending from a main mounting portion 31a having the same length as the second mounting shaft 32 on the right side (Figs. 5 and 6). and Figure 11).

Reference numeral 5 denotes a known jib guide (jib moving means) provided on the left side of the tip of the basic boom 3A.A pair of parallel guide rails 51 and 52 are attached to the left side of the boom in a U-shape to provide a groove rail. It is formed in a shape and consists of an inclined groove part 5a which is inclined downwardly when the boom is in a horizontal state, and a horizontal groove part 5b connected to the rear of this inclined groove part 5a.

33 is an idler sheave provided at the tip of the movable boom 3B, 34 is the main sheave, and 35 is the auxiliary sheave.

On the other hand, the jib 4 has bifurcated first and second jib feet 41 and 42 fixedly installed on both left and right sides of the base end, that is, on the base ends of both the main beams 4a and 4b.
In FIGS. 8 and 9, reference numerals 41a and 42a are fixing pin holes provided through these jib feet 41 and 42.

When in use, the jib 4 is
As shown in FIG. 1, the first jib foot 41 and the second jib foot 42 are respectively engaged and connected to the first jib attachment shaft 31 and the second jib attachment shaft 32, and are extended from the tip of the boom.

When the jib is not in use, the first jib foot 41 and the first main girder 4a are positioned on the lower side, and the first jib foot 42 and the second main girder 4b are positioned on the upper side, as shown in Fig. 1 and Figs. 8 and 9. It is stored on the left side of the boom in a vertical position, and is fixed by a known jib fixing means (not shown).

A box-shaped bracket 43 is fixed to the lower surface of the proximal end of the first main girder 4a of the jib 4, and the connector 6 is attached to the bracket 43 via a rod 61.

Like the jib feet 41 and 42, this connector 6 is
It is formed into a bifurcated shape and is fixed to one end of the rod 61.

The rod 61 is attached to the bracket 43 in a state parallel to the first main girder 4a at a position shifted a predetermined distance d ₁ (shown in FIG. 8) downward from the first main girder 4a in the jib retracted state. Axis center (axis in jib length direction) x
It is rotatably supported around the periphery and slidably supported on the coaxial center x. Note that the rod 61 may be slightly inclined with respect to the axis of the first main girder 4a.

Thereby, the connector 6 is configured to be rotatable around the rod axis x and slidable on the same axis x.

Further, a thrust plate 62 is screwed and fixed to the other end of the rod 61.
2 is in contact with the end surface of the bracket 43,
The rod 61, that is, the connector 6 is in a state in which it protrudes to the maximum extent toward the proximal end of the jib (hereinafter, this state is referred to as an advanced state, and the state in which it slides toward the distal end of the jib from this state is referred to as a retracted state).

In this advanced state, the connecting tool 6 is connected to the first jib foot 41.
The connector 6 protrudes further toward the base end of the jib (d ₂ indicates this protrusion dimension in Fig. 8), and at this extended position, the connector 6
can be engaged with the auxiliary attachment portion 31b of the first jib attachment shaft 31.

Further, as shown in FIGS. 8 to 10, a protruding piece 63 is provided on the outer periphery of the thrust plate 62,
When the jib is retracted, this projecting piece 63 comes into contact with the stopper 44 provided on the front end surface of the bracket 43, thereby preventing the rod 61, that is, the connector 6, from moving backward (the effect of this point will be explained in detail later). ). Note that the protruding pieces 63 are provided at two symmetrical locations,
You can select and use any one.
In FIGS. 8 and 9, numerals 45 and 45 are shaft bearings that rotatably and slidably support the rod 61, and 6a is a pin hole formed through the tip of the connector 6.

On the other hand, as shown in FIGS. 1 and 2, a guide roller 46 is provided protruding from the base of the second main girder 4b of the jib 4, and this guide roller 46 and the jib guide 5 of the boom 3
Accordingly, when the jib is extended, the jib 4 moves from the storage position shown in FIG. 1 to the hanging position shown in FIG. 2, and vice versa when the jib is retracted.

Next, the procedure for extending and retracting the jib using this device will be explained.

Jib extension As shown in FIG. 1, the jib 4 is stored on the side of the boom with the connecting tool 6 facing the first jib mounting shaft 31 from behind, and in this stored state, the tip and middle parts of the basic boom 3A is fixed to the left side of the

Further, at this time, the guide roller 46 is engaged with the horizontal groove portion 5b in the jib guide 5.

(a) With the boom 3 fully retracted and laid down almost horizontally, engage the connector 6 with the auxiliary attachment part 31b of the first jib attachment shaft 31, and insert the fixing pin P into the pin hole 6a. Connector 6 to auxiliary mounting part 31b
The connector is connected so that it cannot be detached from the connector and is rotatable around the attachment portion 31b.

(b) Unfix the jib 4 and raise the boom 3 to about 80 degrees and simultaneously extend it. This boom extension operation causes the guide roller 4
6 is removed from the jib guide 5 from the horizontal groove 5b of the jib guide 5 through the inclined groove 5a. Due to this movement of the guide roller 46, the jib 4 assumes a hanging position with the first jib mounting shaft 31 (auxiliary mounting portion 31b) as a fulcrum, as shown in FIG. In addition,
In FIG. 2, 0 indicates the jib center of gravity.

(c) Twist the jib 4 about 270 degrees around the rod axis x to the state shown in Fig. 3 and then in Figs. 4 and 5.

In the state shown in Figures 4 and 5, both jib feet 41 and 4
2 are in a state of facing both jib mounting shafts 31 and 32 from below, respectively. Furthermore, due to the approximately 270° twist of the jib 4, the stopper 44 of the coupling mounting bracket 43 comes off the protrusion 63 of the thrust plate 62 (as shown by the imaginary line in FIG. 10), so that the coupling 6 moves backward. It becomes possible to do so.

(d) Pass the auxiliary winding wire rope W, which has been passed through the idler sheave 33 and the auxiliary sheave 35 in advance, through the guide sheave 47 at the tip of the jib, and lock the auxiliary hook F attached to the end of the guide sheave to the tip of the jib.

(E) In this state, when the auxiliary wire rope W is hoisted (normally, the boom 3 is extended with the rope fixed), the jib 4 is pulled up while the connector 6 is moved backward due to the tensile force. , the left jib foot 41 is the main attachment part 31 of the first jib attachment shaft 31.
In a, the right jib foot 42 is connected to the right jib mounting shaft 3.
2 (state shown in FIG. 6). In this state, the jib feet 41, 42 and the coupling tool 6 are aligned coaxially.

(f) When the auxiliary winding wire rope W is further wound up, the jib 4 is pulled forward about the jib attachment shafts 31 and 32, and at the same time, the boom 3 is lowered almost horizontally, resulting in the state shown in FIG. 7. In this state, fixing pins (not shown) are inserted into the pin holes 41a, 42a of the jib feet 41, 42 on both sides, respectively, to fix the jib feet 41, 42 on both sides to the jib mounting shafts 31, 32.

(G) Install the suspension rod S between the jib 4 and the tip of the boom, as shown by the imaginary line in Figure 7.

With the above steps, the extension of the jib 4 is completed.

Jib storage Jib storage is performed by following the above-mentioned extension procedure in reverse. To summarize, the boom 3 is laid down almost horizontally, and the suspension rod S is removed in the state shown in FIG. 7 in which the jib 4 is supported by locking the auxiliary hook F to the tip of the jib. Also, remove the left and right jib foot fixing pins, and then raise the boom 3. Next, loosen the auxiliary wire rope W to let the jib 4 hang down as shown in Figure 6, then lower the jib 4 as shown in Figures 4 and 5, and then twist it approximately 270 degrees in the opposite direction to when it was stretched out. The state shown in FIG. 2 is obtained.

At this time, the guide roller 46 faces the entrance of the jib guide 5, and by contracting the boom 3, the guide roller 46 enters the jib guide 5 and moves from the inclined groove part 5a to the horizontal groove part 5b. As a result, the jib 4 is connected to the connecting tool 6 and the first jib mounting shaft 31.
The boom is automatically pulled to the left side of the boom using the connecting point as a fulcrum, and becomes the retracted state shown in Figure 1.

By the way, when the jib 4 is twisted approximately 270 degrees in the storage direction, the stopper 44 of the bracket 43 is in the state shown in FIGS. Reverse movement is prevented by these. Therefore, when pulling the jib, there is no fear that the connector 6 will move backward due to movement resistance of the guide roller 46 with respect to the jib guide 5, and the jib pulling action is reliably performed.

When this device is used, in _the jib retracted state shown in FIG. This distance d ₁ compared to a device whose twist center is the jib foot axis coaxial with the girder.
The entire jib 4 is retracted upward.

That is, by pulling the jib 4 from the hanging state shown in FIG. 2 to the left side of the boom, the jib 4 can be automatically stored in an upper position where it hardly protrudes below the boom, and after pulling the jib 4, it can be retracted upward again. Good forward visibility can be ensured without the need to pull the vehicle up into position.

Further, according to this embodiment, the connecting tool 6 is attached to the jib 4 so as to be able to slide forward and backward, and the connecting tool 6 projects from the jib feet 41 and 42 by a distance d ₂ in the direction of the base end of the jib. jib foot 4
1 and 42 are located closer to the base end of the boom than the jib mounting shafts 31 and 32, so that the jib is pulled and stored with the jib foot engaged with the jib mounting shaft. In comparison, the jib 4 is retracted (shifted back) to the rear position.

Therefore, during crane work with the jib retracted, the jib 4 is shifted back as described above, and the center of gravity of the boom is shifted toward the base end of the boom, reducing the overturning moment, thereby increasing the crane capacity. , the front and rear axle loads are well balanced due to the boom weight when traveling.

Note that after the jib is retracted, the connector 6 may be left in the extended state shown in FIG. Remove from Rod 6
The connector 6 is moved backward by rotating the connector 1 to release the backward lock.

Other Embodiments (a) In the above embodiments, the connector 6 is formed into a bifurcated shape, but the connector 6 may be formed into a ring shape as shown in FIG. 12.

In this case, as a means for removably connecting the ring-shaped connector 6 to the jib attachment shaft 31, in the embodiment shown in FIG.
1b is formed into a hollow pin shape separate from the main attachment part 31a, this auxiliary attachment part 31b is passed through a ring-shaped connector 6, fitted onto the main attachment part 31a, and connected with a pin 31c. There is.

According to this configuration, by removing the auxiliary attachment part 31b when the jib is not in use, the protrusion of the attachment shaft 31 from the side surface of the boom tip can be reduced, making it easier to operate the crane by entering the boom 3 into narrow spaces. be advantageous to

(b) In the embodiment shown in FIGS. 13 and 14, the length of the auxiliary attachment portion 31b of the first jib attachment shaft 31 is This allows the dimensions to be reduced.

Note that this configuration can also be adopted in an embodiment in which the ring-shaped connector 6 shown in FIG. 12 is used and the main attachment part 31a and the auxiliary attachment part 31b of the first jib attachment shaft 31 are configured separately. I can do it.

(c) In the embodiment shown in FIGS. 15 to 17, the rod 61 is arranged so that the connecting tool 6 is located on the axis of the first jib foot 41 in the jib twisted state shown in FIG. The side end of the connector 6 is bent into a crank shape, and this bent portion including the connector 6 is formed by two parallel plates. In the case of this configuration, when the jib 4 is pulled up after twisting the jib, the upper end surface of the first jib foot 41 comes into contact with the lower surface of the bent portion, and this is pushed up so that the jib foot 41 engages with the jib mounting shaft 31. That will happen.

According to this configuration, there is no need to provide the auxiliary attachment part 31b on the first jib attachment shaft 31, so
The protruding dimension of this mounting shaft 31 can be minimized.

(d) In the embodiment shown in FIG.
1 is fixed to the jib 4 via a bracket 43, and a connector 6 is attached to the end of the rod 61 so as to be rotatable and slidable around the rod axis.

(e) In the embodiment shown in FIG.
1 is rotatably fixed to the bracket 43 of the first main girder 4a of the jib, but is fixed in the axial direction, and the connector 6 is formed into a long bifurcated shape.

According to this configuration, after the jib is twisted during extension,
When the jib 4 is pulled up, the connector 6 slides upward together with the jib 4 within the range of crotch depth relative to the jib mounting shaft, and the jib foot 41 engages with the jib mounting shaft. Alternatively, in the case of adopting the configuration shown in FIG. 12, the same effect as described above can be obtained even if the ring-shaped connector 6 is formed to be long in the axial direction of the rod 61.

(f) In each of the above embodiments, in order to shift and store the jib 4 as far as possible toward the boom base end as described above, the connector 6 is moved with a relatively large stroke with respect to the jib 4 or the first jib mounting shaft 31. However, if the shift back function is not required, the sliding stroke of the coupling device 6 is such that the jib feet 41 and 42 move toward the jib mounting shaft 31 and Only the stroke necessary to move from the position facing closely below the mounting shafts 31 and 32 to the position engaging the mounting shafts 31 and 32 is sufficient.

Alternatively, if the jib feet 41 and 42 are formed into a U-shape as shown in FIG. 20, these will directly engage the jib mounting shafts 31 and 32 when the jib is twisted, so that sliding of the coupling tool 6 will be unnecessary.

(g) As a jib moving means for moving the jib 4 between the hanging position and the storage position, in addition to the jib guide 5 and guide roller 46 exemplified in the above embodiment, the method disclosed in Japanese Patent Application Laid-Open No. 61-86386 can be used. Alternatively, a structure in which the jib is moved by a rope may be used, as shown in Japanese Patent Application Laid-Open No. 130883/1983 (Japanese Patent Publication No. 62-837).

[Effect of idea]

As described above, according to the present invention, a coupling device is provided on the lower side of the jib when the jib is in the retracted state, and is rotatable around the longitudinal axis of the jib that is shifted downward with respect to the lower side of the jib. 1 When connected to the jib mounting shaft, the jib is suspended using this connection point as a fulcrum, and is twisted around the shaft to extend and store, so when the jib is stored,
The jib can be set at an upper position on the side of the boom with almost no downward protrusion of the boom.
This makes it possible to ensure good forward visibility when driving.

Furthermore, since the jib retracting action to the above-mentioned upper position is automatically accomplished only by the jib pulling operation, it is not possible to , there is no need for the troublesome work of lowering the jib in the stowed position when extending it, and then pulling it up again after pulling the jib when stowing it.
The work efficiency of extending and retracting the jib can be improved.

[Brief explanation of the drawing]

Figures 1 to 11 show the basic embodiment of the present invention, with Figure 1 showing the jib in the retracted state, Figure 2 in the hanging state, Figure 3 in the middle of twisting the jib, and Figure 4 in the completed state of twisting the jib. Fig. 5 is a side view showing the 4th
Figure 6 is a front view of the state in which the jib is pulled up vertically, Figure 7 is a side view of the jib in its extended state, Figure 8 is a partially enlarged view of the state shown in Figure 1, and Figure 9 is a front view of the state shown in Figure 1. FIG. 10 is an enlarged sectional view taken along the line A-A in FIG. 8, FIG. 11 is a partially enlarged view of FIG. 6, and FIG. 13 is a diagram equivalent to FIG. 9 showing another embodiment, FIG. 14 is a diagram equivalent to FIG. 11 of the embodiment in FIG. 13, and FIG. 15 is a diagram equivalent to FIG. 11 showing yet another embodiment. 5 is a partially enlarged front view of the stage, FIG. 16 is a view corresponding to FIG. 11, FIG. 17 is a sectional view taken along line B-B in FIG.
Fig. 19 is a perspective view showing yet another embodiment, Fig. 20 is a view equivalent to Fig. 8 showing yet another embodiment, and Fig. 21 is a side view of the conventional example with the jib extended. , FIG. 22 is a plan view of the same, FIG. 23 is a side view showing the same jib in the hanging state, and FIG. 24 is a side view showing the same jib in the retracted state. 3... Telescopic boom, 31... First jib mounting shaft,
31a... Main mounting part of the mounting shaft, 31b... Auxiliary mounting part, 4... Jib, 4a... First main spar of the jib (lower side of the jib), 4b... Second main spar, 41... 1st
Jib foot, 42... Second jib foot, 5... Jib guide as jib moving means, 46... Guide roller, 6... Connecting tool, 61... Rod for attaching the connecting tool, x... Rod axis center ( (axis in the jib length direction that is offset downward from the bottom of the jib).

Claims (1)

[Scope of utility model registration request] A first jib mounting shaft is provided on one side of the left and right sides of the tip of the telescopic boom, and a second jib mounting shaft is provided on the other side, while a second jib mounting shaft is provided at the base end of the jib that is detachably connected to both of the jib mounting shafts. A first and a second jib foot are provided, and the jib is placed so that the first jib foot is on the lower side and the second jib foot is on the lower side.
Store the jib on the side of the boom in a vertical position with the jib foot at the top, let the jib hang down from the stored position, then twist it, swing it forward, extend it to the tip of the boom, and store it in the reverse order. In the crane, a connector is attached to the lower side of the base end of the jib in the jib stored state, and is connected to the first jib mounting shaft in a removable and rotatable manner around the first jib mounting shaft. The state in which the jib is rotatably mounted around an axis in the longitudinal direction of the jib that is shifted downward relative to the lower side of the jib, and when the jib is extended, the jib is connected to the first jib attachment shaft. A jib extension and storage device for a crane, characterized in that the jib is moved from a storage position to a hanging position using this connection point as a fulcrum, and is moved in the opposite direction when the jib is stored.