JPH0350148Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a wheel crane such as a truck crane or a rough terrain crane, in which a compression column type jib (hereinafter simply referred to as a jib) is extended and retracted using the so-called jib twist method. This relates to a jib extension and storage device.

[Conventional technology]

An example of the basic configuration and jib storage procedure of a conventional device for extending and storing a jib using the above-mentioned jib twist method will be briefly explained with reference to FIGS. 16 to 19.

(A) Jib mounting shaft 1 on both left and right sides of the tip of boom 1
1 and 12 are installed protrudingly.

(B) Both sides of the base end of the jib 2 (left and right as seen from the driver's cab when the jib is extended, the same is true for the following left and right directionality), that is, the main girder 2 on both sides of the jib
Bifurcated jib feet 21 and 2 that can be engaged with and detached from the jib mounting shafts 11 and 12 are provided at the base ends of a and 2b.
2 will be provided.

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

(D) When the jib 2 is used, the movable jib foot 21 is attached to the left jib mounting shaft 11 as shown in Figures 16 and 17.
, attach the fixed jib foot 22 to the right jib mounting shaft 12.
Extend it from the tip of the boom with each of them engaged. In Fig. 16, S indicates jib 2 in this extended state.
It is a suspension rod that supports.

Jib storage procedure (a) Remove the suspension rod S and attach only the movable jib foot 21 to the left boom point pin 11.
In the engaged and connected state, the jib 2 is suspended below the tip of the boom as shown by the imaginary line in FIG. W
At this time, the end of the auxiliary wire rope supporting the jib 2 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 18.
Twist and rotate about 270° around the axis of the movable jib foot 21.

(c) Pass the auxiliary winding wire rope W through the guide sheave 23 provided at the tip of the jib, and with the end fixed to the boom base, slowly wind up the auxiliary winding wire rope W, as shown in Fig. 19. As shown in , pull the jib 2 to the left side of the boom 1 around the left boom point pin 11.

(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 attempts to solve]

However, according to the conventional device, as described above, the jib 2 is pulled to the left side of the boom using the movable jib foot 21 provided at the base end of the left main girder (lower main girder in the retracted state) 2a of the jib 2 as a fulcrum. Since the configuration is such that the jib is retracted, the left main girder 2 of jib 2 is
The majority of the section a (shown with diagonal lines in FIG. 19) is supposed to protrude 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, Japanese Unexamined Patent Publication No. 1986-86386, Utility Model Application No. 61-86386,
As shown in Publication No. 72583, after pulling the jib to the side of the boom, the jib and boom are connected via a pulley, and by extending the boom, the jib is moved to an upper position where it does not protrude downward as much as possible. A device that can be pulled up is known.

However, according to this configuration, the jib raising process (the reverse lowering process when the jib is extended) is required, which makes the stowing and extending operations troublesome, and has the disadvantage of deteriorating work efficiency.

Therefore, the present invention provides 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 jib raising and lowering operation in the storage position as described above. It is something to do.

[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 ends of the main girders on both sides of the jib to be detachably connected to both the jib mounting shafts. , the jib is placed vertically on the side of the boom, with the first jib foot and the first main girder to which the jib foot is attached are on the lower side, and the second jib foot and the second main girder to which the jib foot is attached are on the upper side. With the first jib foot connected to the first jib mounting shaft, the jib is suspended from the stowed position using this connection point as a fulcrum, then twisted, and then swung forward to attach it to the tip of the boom. This is a crane that is extended and retracted in the reverse order, and has the following configuration.

() Attach the first jib foot to the tip of the rod member bent into a crank shape.

() The first jib foot moves coaxially with the axis of the first main spar of the jib between a position where it engages and a position where it separates from the base end of the first main spar, and the jib retracts. The rod member is attached to a portion near the proximal end of the first main spar of the jib in a state in which it can rotate around an axis in the lengthwise direction of the jib located below the first main spar in the first main spar.

() Equipped with a jib moving means that moves the jib from the storage position to the hanging position when extended and vice versa when stored.

() A jib lifting means is provided for pulling the jib directly upward in a hanging state and engaging the base end of the first main girder of the jib with the first jib foot.

() A means is provided for detachably connecting the base end of the first main girder and the first jib foot in an engaged state.

[Effect]

With this configuration, when the jib is stored, the first main girder of the jib is drawn to the side 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.

In addition, since the first jib foot is coaxially connected to the first main girder of the jib and is engaged and connected to the first jib mounting shaft, the first
The length of the jib mounting shaft can be short. This is advantageous when performing crane work by passing the boom through a narrow space.

(Example) An example of the present invention will be described with reference to FIGS. 1 to 15.

Basic Embodiment (See FIGS. 1 to 13) 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 configured 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.

The boom 3 has a first jib attachment shaft 31 and a second jib attachment shaft 32 horizontally protruding from the left side and the right side of the tip of the movable boom 3B, respectively.

Reference numeral 5 denotes a known jib guide as a jib moving means provided on the left side of the tip of the basic boom 3A, and a pair of parallel guide rails 51 and 52 are attached to the left side of the boom in a U-shape. It is formed in the shape of a groove track 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 is provided with bifurcated first and second jib feet 41 and 42 on both sides of its base end, that is, at the base ends of both main beams 4a and 4b. In FIGS. 8 and 9, 41a and 42a are pin holes provided through these jib feet 41 and 42.

When the jib 4 is in use, it is extended from the tip of the boom with both jib feet 41 and 42 being engaged and connected to the jib mounting shafts 31 and 32, respectively, as shown in FIG. 7, and when not in use, as shown in FIG. and 8th and 9th
As shown in the figure, the first main girder 4a and the first jib foot 41 are located on the lower side, and the second main girder 4b and the second jib foot 42 are placed on the upper side. It is fixed by known jib fixing means (not shown).

Of the two jib feet 41, 42, the second jib foot 42 is fixed to the base end of the right main girder 4b, as in the conventional case.

On the other hand, the first jib foot 41, which is located on the lower side when the jib is stored, is attached to the vicinity of the base end of the first main girder 4a via a jib foot attachment device (hereinafter simply referred to as the attachment device) 6 as follows. There is.

The attachment device 6 is attached to the first main girder 4a in the jib storage state.
A box-shaped bracket 61 fixed to the bottom surface of the base of
It consists of a straight rod 62 inserted and supported by this bracket 61, and an L-shaped bent rod 63 connected to the base end of this straight rod 62 (the end in the direction of the base end of the jib). A jib foot 41 is fixed to the tip of the jib foot 41.

The straight rod 62 is parallel to the first main girder axis l at a position shifted downward by a predetermined distance d ₁ (shown in FIG. 8) with respect to the first main girder 4a, and is attached to the bracket 61 around the rod axis x. It is mounted so that it can rotate freely and slide freely on the coaxial center x.

In this way, the jib foot 41 is configured to be able to freely rotate around the axis (rod axis) x that is parallel to and shifted downward from the first main girder 4a in the jib retracted state, and to be able to slide along the rod axis x. ing.

Note that the straight rod 62 may be slightly inclined with respect to the first main girder axis l. Further, the first jib foot 41 is fixed to the bending rod 63 in a state in which it is eccentric by the same distance as the eccentric distance d ₁ of the straight rod 62 with respect to the first main girder 4a with respect to the rod axis x. Approximately in a predetermined direction relative to the main girder 4a from the state when the jib is stored as shown in Figures 8 and 9.
270°rotated state (states shown in Figures 11 to 13)
It is positioned coaxially with the first main spar 4a, and in this state can slide to engage with and separate from the base end portion 43 of the first main spar 4a.

Like both jib feet, the first main girder base end portion 43 is formed into a bifurcated shape, and engages with the bent portion 63a of the bending rod 63 so as to sandwich it when engaged with the first jib foot 41.

The main spar proximal end 43 and the bent portion 63a of the bent rod 63 (hereinafter referred to as the main spar side connecting portion and the jib foot side connecting portion) are provided with pin holes 44, 64 that match in the engaged state. are provided, and by inserting the connecting pins 7 (shown by imaginary lines in FIG. 13) into the pin holes 44, 64, these connecting portions 43, 63a, that is, the first main girder 4a and the first The jib foot 41 is coaxially connected and integrated.

In addition, in the mounting device 6, a thrust plate 65 is screwed and fixed to the base end of the straight rod 62.
With this thrust plate 65 in contact with the base end surface of the bracket 61, the straight rod 62 advances from the bracket 61 to the maximum direction toward the base end of the jib, and in this state, the first jib foot 41 is moved from the first main girder 4a. A maximum separation state is reached (hereinafter, this state is referred to as a maximum separation state. In FIG. 8, d ₂ indicates the separation dimension in this state).

Furthermore, as shown in FIGS. 8 to 10, the thrust plate 65 is provided with a projecting piece 65a on its outer periphery, and when the jib is retracted, this projecting piece 65a hits a stopper 66 provided on the base end surface of the bracket 61. This contact prevents the linear rod 62 from moving toward the tip of the jib, that is, from moving the first jib foot 41 toward the first main girder 4a (the effect of this point will be described in detail later). .

Note that the protrusions 65a are provided at two symmetrical locations, and any one of them can be selectively used. In FIG. 8, reference numerals 67, 67 are shaft bearings that rotatably and slidably support the linear rod 62.

On the other hand, as shown in FIGS. 1 and 2, a guide roller 45 is provided protruding from the upper surface of the base of the second main girder 4b located above the jib 4 in the retracted state, and this guide roller 45 and the jib guide 5 of the boom 3 Accordingly, the jib 4 moves from the storage position shown in FIG. 1 to the hanging position shown in FIG. 2 when the jib is extended, and vice versa when the jib is retracted.

The second jib foot 42 is in a positional relationship such that the position in the jib length direction matches the first jib foot 41 in the state shown in FIGS. 6 and 12 when the first jib foot 41 is connected to the first main girder 4a. It is attached to the base end portion of the second main girder 4b.

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

Jib Extension The jib 4 is fixed to the left side surface of the basic boom 3A at its tip and middle portion in the retracted state shown in FIG.
Also, at this time, the guide roller 45 is
The horizontal groove portion 5b is engaged with the horizontal groove portion 5b in the horizontal groove portion 5b.

(a) With the boom 3 fully retracted and laid down almost horizontally, move the first jib foot 41 to the first jib mounting shaft 31.
and insert the fixing pin 8 into the pin hole 41a to attach the jib foot 41 to the jib mounting shaft 31.
It is connected to the mounting shaft 31 so that it cannot be separated from the mounting shaft 31 and is rotatable about the mounting shaft 31.

(b) Unfasten the jib 4, raise the boom 3 to about 80 degrees, and simultaneously extend it.

This boom extension operation causes the guide roller 4 to
5 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 45, the jib 4 is moved to the first position relative to the first jib mounting shaft 31 as shown in FIG.
It assumes a hanging position using the connection point of the jib foot 41 (hereinafter referred to as the left connection point) as a fulcrum. In addition, in FIG. 2, 0 indicates the jib center of gravity.

(c) Twist the jib 4 about 270° around the rod axis x of the mounting device 6, and then
The state is as shown in FIGS. 5 and 11.

In this state, the main girder side connecting portion 43 faces the jib foot side connecting portion 63a, and the second jib foot 42 faces the second jib mounting shaft 32 from below. Furthermore, due to the approximately 270° twist rotation of the jib 4, the stopper 66 of the bracket 61 in the mounting device 6 is moved against the thrust plate 65.
Since the rod 6 comes off the protruding piece 65a (the state shown by the imaginary line in FIG. 10), the rod 6 becomes in a state in which it can move toward the tip of the jib.

(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 46 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 tension force causes the rod 62 of the attachment device to slide and the jib 4 to move. The connecting portion 43 of the first main girder 4a is connected to the jib foot side connecting portion 63a, and the second jib foot 42 is connected to the second
The jib mounting shafts 32 are respectively engaged (states shown in FIG. 6 and FIGS. 12 and 13). It is only in this state that the second jib foot 42 connects to the first jib foot 41.
line up in the same row on the left and right.

(F) When the auxiliary winding wire rope W is further wound up, the jib 4 is swung 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, the first jib foot 41 and the first main girder 4
A are connected to each other by the pin 7 at the connecting parts 43 and 63a, and a pin (not shown) is inserted into the pin hole 42 of the second jib foot 42 to fix the same jib foot 42 to the second jib mounting shaft 32. do.

(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 overhanging means in reverse.

To summarize the main points, lower the boom 3 almost horizontally, lock the auxiliary hook F to the tip of the jib, and lower the jib 4.
7, remove the suspension rod S, the second jib foot fixing pin, and the connecting pin 7.

Next, raise the boom 3 and use the auxiliary wire rope W.
After loosening and letting the jib 4 hang down as shown in Figure 6, and further lowering the jib 4 as shown in Figures 4 and 5,
Twist it approximately 270 degrees in the opposite direction to when it is stretched out to get the state shown in Figure 2.

At this time, the guide roller 45 faces the entrance of the jib guide 5, and by contracting the boom 3, the guide roller 45 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 automatically drawn to the left side of the boom using the connection point between the first jib mounting shaft 31 and the jib foot 41 as a fulcrum, and enters the retracted state shown in FIG. 1.

By the way, when the jib 4 is twisted approximately 270 degrees in the storage direction, the bracket 61 in the mounting device 6
The stopper 66 is the protrusion 6 of the thrust plate 65.
5a in the circumferential direction, as shown in FIGS. 8 to 10, and movement of the rod 62 toward the tip of the jib is thereby prevented. Therefore, when pulling the jib, the guide roller 4 relative to the jib guide 5
There is no fear that the rod 62 will move backward due to the movement resistance of 5, and the jib pulling action can be performed reliably.

When this device is used, when the jib is stored _in the state shown in FIG. Compared to a device in which the twist center is the jib foot axis coaxial with the first main girder, the entire jib 4 is retracted upward by this distance d ₁ minute. 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 is
The boom can be automatically stored in an upper position where it hardly protrudes downward, and good forward visibility can be ensured without the need to pull the jib 4 up again after pulling it to the upper position.

By the way, as a means to obtain the same effect as this device, both jib feet are fixedly installed at the base end of the main spar, as in the conventional case, and at the same time, a jib foot is installed from the first main spar 4a on the lower surface of the first main spar 4a when the jib is in the retracted state. A connecting tool that is rotatable and slidable around the shaft shifted downward is provided separately from the first jib foot, and this connecting tool is connected to a portion extending from the first jib mounting shaft,
A conceivable method is to suspend and twist the jib using this connection point as a fulcrum, and then pull up the jib to engage and connect both jib feet to both jib mounting shafts.

However, according to this method, on the left side of the boom tip,
Since it is necessary to install the mounting shaft for the jib foot and the shaft for the coupling on the same axis, the overall length of this shaft becomes long, which is disadvantageous for crane work that involves passing the boom through narrow spaces. be.

On the other hand, according to this device, the first jib foot 4
1 itself is configured to be freely rotatable and slidable around an axis
Since the structure is such that the main girder 4a is connected coaxially,
On the left side of the boom tip is the mounting shaft 3 for the first jib foot.
It is sufficient to provide only 1. Therefore, this shaft length can be shortened, which is advantageous for the above-mentioned crane operation.

Furthermore, according to this device, the first jib foot 4
1 is slidably attached to the first main girder 4a, and the jib foot 41 protrudes from the first main girder 4a by a distance d ₂ in the direction of the base end of the jib. Since the structure is such that the second jib foot 42 is pulled and stored in a state where it is located closer to the boom base end than the jib mounting shafts 31 and 32, the first jib foot 21 is attached to the first main girder 2a as shown in FIGS. 16 to 19. Compared to the conventional device which pulls and stores the jib with the jib foot 21 engaged with the jib mounting shaft 11, the entire jib 4 is stored (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 storing the jib, the first jib foot 41 is
As shown in the figure, there is no problem in keeping the rod 62 engaged with the first jib mounting shaft 31, but normally the rod 62 is rotated with the jib mounting shaft 31 removed from the first jib foot 41 due to boom extension. Then, the first jib foot 41 is moved toward the tip of the jib through a procedure of releasing the backward lock.

Other Embodiments (a) In the basic embodiment described above, the first jib foot 41 is formed into a bifurcated shape that can be engaged with and detached from the first jib mounting shaft 31 in the length direction of the jib. 41 may be formed into a U-shape, and when the jib is extended, the jib foot 41 may be rotated about the rod axis x and engaged with the jib mounting shaft 31.

(b) As another example of the mounting structure of the first jib foot 41, in the embodiment shown in FIG. It is mounted so that it can freely rotate and slide around the axis x. With this configuration as well, it is possible to obtain the same effects as in the above embodiment.

(c) In the basic embodiment, the slide stroke of the first jib foot 41 relative to the first main girder 4a was set relatively large in order to shift back the jib 4 to the boom base end side and store it as much as possible. If the jib foot 41 is not required, the slide stroke of the jib foot 41 may be only the stroke necessary to attach and detach the jib foot 41 to and from the main girder 4a.

(d) 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 45 illustrated in the above embodiment, the method disclosed in Japanese Patent Application Laid-Open No. 61-86386 Alternatively, a structure in which the jib is moved by a rope may be used, as shown in Japanese Patent Application Laid-open No. 58-130883 (Japanese Patent Publication No. 62-837).

[Effect of idea]

As described above, according to the present invention, the first jib foot can freely rotate around the axis that is shifted downward from the first main girder with respect to the base end of the first main girder, and can slide coaxially with the first main girder. with the first jib foot connected to the first jib mounting shaft, the jib is suspended about this connection point as a fulcrum,
In addition, since the structure is such that the jib is twisted around the axis, extended, and retracted, when the jib is stored, the jib can be set at an upper position on the side of the boom where there is almost no downward protrusion of the boom. It is possible to secure forward visibility.

Moreover, since the jib retracting operation to the upper position is automatically performed only by the jib pulling operation, there is no need to pull the jib back to the upper position after storing the jib.

In addition, since the first jib foot itself is configured to be freely rotatable and slidable around an axis that is shifted downward from the first main girder, a coupling device that performs the same function is provided on the jib separately from the jib foot. Compared to other methods in which the shaft portion of the jib is extended to the jib mounting shaft, the length of the jib mounting shaft can be shortened (same as before), which is advantageous for crane operations.

[Brief explanation of drawings]

Figures 1 to 13 show the basic embodiment of the present invention. Figure 1 shows the jib in the retracted state, Figure 2 shows the jib in the hanging state, Figure 3 shows the jib in the middle of twisting, and Figure 4 shows the jib in the completed twisting state. Side view shown, fifth
The figure is a front view of the state shown in Fig. 4, Fig. 6 is a front view of the state in which the jib is pulled up vertically, Fig. 7 is a side view of the jib extended state, and Fig. 8 is a partially enlarged view of Fig. 1. Figure 9 is an enlarged perspective view of the same, Figure 10 is Figure 8A.
-A line enlarged sectional view, Fig. 11 is a partial enlarged view of Fig. 5, Fig. 12 is a partial enlarged view of Fig. 6, Fig. 13 is a sectional view taken along the line B-B of Fig. 12, and Fig. 14 is a partial enlarged view of Fig. 5. FIG. 15 is a view equivalent to FIG. 9 showing another embodiment of the invention, FIG. 15 is a view equivalent to FIG. 11 showing another embodiment, FIG. FIG. 18 is a plan view of the jib, FIG. 18 is a side view showing the jib in the hanging state, and FIG. 19 is a side view showing the jib in the retracted state. 3... Telescopic boom, 31... First jib mounting shaft,
4... Jib, 4a... First main girder, 41... First jib foot, 42... Second jib foot, 6... First
Jib foot mounting device, 61... Bracket of the device, 62... Straight rod constituting a crank-shaped rod member, x... Axis center of the straight rod (axis shifted downward with respect to the first main girder), 63...Bending rod, 64, 44... Pin hole constituting the connecting means,
7... Connecting pin, 5... Jib guide constituting the jib moving means, 45... Guide roller, W...
Auxiliary winding wire rope constituting the jib pulling means, F
...The same supplement.

Claims (1)

[Scope of Claim for Utility Model Registration] 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. The first and second parts are removably connected to the mounting shaft.
A jib foot is provided, and the jib is placed in a vertical position in which the first jib foot and the first main girder to which the jib foot is attached are on the lower side, and the second jib foot and the second main girder to which the jib foot is attached are on the upper side. This jib is stored on the side of the boom and attached to the first
A crane in which, with the jib foot connected to the first jib mounting shaft, the jib foot is suspended from the storage position using this connection point as a fulcrum, then twisted, and further swung forward to extend over the tip of the boom, and then stored in the reverse order. A crane jib extension and storage device characterized by having the following configuration. () Attach the first jib foot to the tip of the rod member bent into a crank shape. () The first jib foot moves coaxially with the axis of the first main spar of the jib between a position where it engages and a position where it separates from the base end of the first main spar, and the jib retracts. The rod member is attached to a portion near the proximal end of the first main spar of the jib in a state in which it can rotate around an axis in the lengthwise direction of the jib located below the first main spar in the first main spar. () Equipped with a jib moving means that moves the jib from the storage position to the hanging position when extended and vice versa when stored. () A jib lifting means is provided for pulling the jib directly upward in a hanging state and engaging the base end of the first main girder of the jib with the first jib foot. () A means is provided for removably connecting the base end of the first main girder and the first jib foot in an engaged state.