JPH0350149Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a jib extension and storage device for extending and storing a jib (compression column type jib) using a so-called jib twist method in a truck crane, rough terrain crane, etc. It is something.

[Conventional technology]

In the crane that uses the jib twist method described above, the jib is stored vertically on the side surface, and when extended, the jib is connected to the tip of the boom on either the left or right side of the base end so that it can rotate around the horizontal horizontal axis. After hanging down using this connection point as a fulcrum, the jib is twisted at a predetermined angle (for example, about 270°), and the jib is operated in the opposite direction when retracting (for example, as disclosed in Japanese Patent Laid-Open No. 58-130883, 58
-Refer to Publication No. 130884).

[The problem that the idea attempts to solve]

In this case, when using the conventional jib extension and storage device, the above-mentioned twisting operation of the jib must be performed manually by the worker (crane operator), which not only imposes a large labor burden on the operator, but also (b) This manual twisting operation requires the operator to come down from the operator's cab each time, resulting in poor work continuity; and (b) the extra step of lowering the boom to the position where the jib can be manually twisted. The efficiency of jib extension and retraction work was poor due to the necessity of

Therefore, the present invention provides a jib extension and storage device for a crane that can automatically perform jib twisting operations when extending and retracting the jib.

[Means to solve the problem]

The present invention provides horizontal horizontal shafts on both left and right sides of the tip of the boom, and connecting parts on both sides of the base end of the jib that are detachably connected to the shafts and rotatable around the coaxial bodies. One of the joints of the jib has a rod rotatably supported on the jib around the longitudinal axis of the jib, and when the joint with this rod is connected to one shaft, the jib is is suspended from the storage position using this connection point as a fulcrum, then twisted, and then swung forward.
This crane has the following configuration, in which the connecting parts on both sides extend from the tip of the boom while being connected to the shafts on both sides, and are stored on the sides of the boom in the reverse order.

() Around the rod of one of the above connection parts,
Both the first and second springs are wound in opposite winding directions.

() When the rod rotates in one direction, elastic force is accumulated in the direction opposite to this rotation, and when the rod rotates in the other direction, elastic force is not accumulated in the first spring. is fixed to the jib,
The other end must be secured to the rod.

() When the rod rotates in the other direction, the second spring accumulates an elastic force in a direction that opposes this rotation, and when the rod rotates in the one direction, no elastic force is accumulated. , one end is fixed to the jib and the other end is locked to the rod.

() A means is provided to stop the jib from twisting due to the elastic force of the two springs until the jib reaches the twisting start position when the jib is extended and when the jib is retracted.

[Effect]

With this configuration, the jib can be automatically twisted in the extending and retracting directions by the elastic force accumulated in the pair of springs, thereby realizing automation of the twisting process and continuous work.

〔Example〕

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

Basic Embodiment (See Figures 1 to 12) 1 is a telescopic boom, and 2 is a compression column type jib. The boom 1 usually includes a basic boom and multiple stages of movable booms. However, in order to make the explanation easier to understand, here, a case is shown in which the boom 1 is configured as a one-stage telescoping type consisting of only a basic boom 1A and a single-stage movable boom 1B.

The jib 2 has a tapered end with a plurality of connecting bars 2c attached between the main girders 2a and 2b on both sides (the left and right as seen from the driver's cab when the jib is extended; the same goes for the left and right directions below). It is structured like a ladder.

The boom 1 has jib attachment shafts (shaft bodies) 11 and 12 horizontally protruding from both left and right sides of the tip of the movable boom 1B.

Of these, the left jib mounting shaft 11 has an auxiliary mounting portion 11b extending integrally with a main mounting portion 11a having the same length as the right jib mounting shaft 12 (fifth,
6 and 12).

3 is a known jib guide provided on the left side of the tip of the basic boom 1A, and is formed into a groove track shape by attaching a pair of parallel guide rails 31 and 32 to the left side of the boom in a shape seen from the side. is,
Slanted groove part 3 that slopes downward when the boom is horizontal
a, and a horizontal groove 3b connected to the rear of the inclined groove 3a.

13 is an idler sheave provided at the tip of the movable boom 1B, 14 is the main sheave, and 15 is the auxiliary sheave.

On the other hand, the jib 2 has bifurcated jib feet 21 and 22 fixedly installed on both left and right sides of its base end, that is, at the base ends of both main beams 2a and 2b.

Of these two jib feet 21, 22, the left side jib foot 21 is formed into a bifurcated shape with both legs having the same length, and the right side jib foot (right side connecting portion) 22 is formed into a bifurcated shape with one leg longer than the other. It is formed in the shape of In FIGS. 8 and 9, reference numerals 21a and 22a are fixing pin holes provided through both of these jib feet 21 and 22.

As shown in Figures 6, 7 and 12, the jib 2 is extended from the tip of the boom with jib feet 21 and 22 on both sides engaged and connected to the jib mounting shafts 11 and 12 on both sides, respectively, and when not in use. As shown in Fig. 1 and Figs. 8 and 9, the left main girder 2a and left jib foot 21 are located on the lower side, and the right main girder 2b and right jib foot 22 are placed on the upper side. , by a known jib fixing means (not shown).

In this jib 2, a cylindrical housing 23 is fixed to the lower surface of the proximal end of the lower main girder 2a in the retracted state via a bracket 23a.
A connecting body 4 is attached to the body via a rod 41.

In this way, the left side jib foot 21 and the connecting body 4 with the rod 41 constitute a left side connecting portion.

This connecting body 4, like the jib feet 21 and 22,
It is formed into a bifurcated shape and is fixed to one end of the rod 41.

The rod 41 is attached to the housing 23 with bearings on both sides in a position parallel to the lower main girder 2a at a position deviated a predetermined distance d ₁ (shown in FIG. 8) downward from the left main girder 2a in the jib retracted state. The rod is rotatably supported via 24, 24 around the rod axis x and slidably on the coaxial center x. Note that the rod 41 may be slightly inclined with respect to the axis of the lower main girder 2a.

Thereby, the connecting body 4 is configured to be rotatable around the rod axis x and slidable on the same axis x.

Further, a thrust plate 42 is fixed to the other end of the rod 41, and with this thrust plate 42 in contact with one end surface of the housing 23, the rod 41, that is, the connecting body 4 is moved as far as possible in the direction of the base end of the jib. Prominent state (hereinafter referred to as advanced state)
The state in which the jib slides toward the tip from this state is called the backward state). In this advanced state, the connecting body 4 protrudes from the lower (left side) jib foot 21 toward the base end of the jib (in FIG. 8, d ₂ indicates the dimension of this protrusion). In FIG. 9, 4a is a pin hole penetrated through the tip of the connecting body 4.

Further, as shown in FIG. 8 and FIGS. 10 and 11, inside the housing 23, both the first and second spiral springs 5 and 6 are wound around the rod 41 with their respective winding directions reversed. There is.

The inner peripheral ends 51, 61 of both springs 5, 6 are engaged with spring hooks 41a, 41b which are partially stepped on the outer peripheral surface of the rod, and the outer peripheral ends 52, 62
is fixedly attached to a spring fixing pin 25 extending through the housing 23 in the axial direction.

In this way, rotation of the rod 41 in one direction (for example, rotation to the left when viewed from the tip of the jib as indicated by the arrow in FIG. 10) causes the first spring 5 to be activated, and rotation in the opposite direction as indicated by the arrow in FIG. An elastic force is accumulated in each of the springs 6, and the accumulated elastic force acts as a relative rotational force between the rod 41 and the housing 23, that is, between the connecting body 4 and the jib 2. has been done.

Therefore, when the rod 41 (coupling body 4) is fixed, the above elastic force acts on the jib 2 as a torsional force in the extending or retracting direction.

Both springs 5 and 6 are fixed in the axial direction with respect to the rod 41 by washers 43, 44, and 44 fixed to the rod 41 between the two springs and on the outside of both springs, and with respect to the housing 23. pin 25
Since they are respectively attached so as to be movable in the axial direction along the rod 41, they slide together with the rod 41.

The washers 43 also serve to prevent the springs 5, 6 from coming into contact with each other, and the washers 44, 44 also serve to prevent the springs 5, 6 from coming into contact with the bearings 24, 24 on both sides.

On the other hand, as shown in FIGS. 1 and 2, a guide roller 26 is provided protruding from the upper surface of the base of the upper main girder 2b in the stored state of the jib 2, and this guide roller 26 and
The jib guide 3 of the boom 1 allows the jib 2 to move 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.

Further, as shown in FIGS. 4 to 7, at the tip of the jib, a substantially U-shaped hook hook 7 on which an auxiliary hook F is hooked when the jib is extended is provided at the portion where the guide sheave 27 is provided. There is.
The hook hanging device 7 has two positions, centered around the attachment point to the tip of the jib, in a forward hooking position as shown by the solid line in FIG. It is mounted so that it can rotate between the

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

Jib extension The jib 2 is fixed to the left side surface of the basic boom 1A at its tip and middle part in the retracted state shown in FIG.
Also, at this time, the guide roller 26 is
The horizontal groove portion 3b is engaged with the horizontal groove portion 3b.

(b) With the boom 1 fully retracted and laid down almost horizontally, the connecting body 4 is
(Rod 41) is rotated to the left by a predetermined angle (basically, the jib twist angle = approximately 270°).

As a result, the first spring 5 is tightened to accumulate elastic force in the direction of resisting rod rotation, that is, rotational force in the direction of twisting the jib 2 when extended. At this time, since the rod 41 idles relative to the second spring 6, the spring 6 is kept in a free state (loose state) and no elastic force is accumulated.

(b) Engage the connecting body 4 to be rotated as described above with the auxiliary attachment part 11b of the left jib attachment shaft 11, and insert the fixing pin P into the pin hole 4a as shown in FIGS. 8 and 9. Connecting body 4 to auxiliary mounting part 11b
It is connected to the mounting portion 11b so that it cannot be separated from the mounting portion 11b and is rotatable about the mounting portion 11b.

Further, the hook hooking tool 7 at the tip of the jib is set at the hook hooking position shown by the solid line in FIG. 4.

(c) Unfasten jib 2, raise boom 1 to about 80 degrees, and simultaneously extend it.

This boom extension operation causes the guide roller 2
6 is removed from the jib guide 3 from the horizontal groove 3b of the jib guide 3 through the inclined groove 3a. Due to this movement of the guide roller 26, the jib 2 assumes a hanging position with the left jib mounting shaft 11 (auxiliary mounting portion 11b) as a fulcrum, as shown in FIG. In addition,
In FIG. 2, 0 indicates the jib center of gravity.

(d) When the jib 2 reaches the hanging position, which is the twisting start position, (when the guide rollers 26 come off the jib guide 3), the jib 2 is freed from its restraints and can freely rotate to the left. , the jib 2 is automatically twisted around the rod axis x by the elastic force (jib rotational force) accumulated in the first spring 5.

Therefore, there is no need for the operator to get out of the operator's cab and manually twist the jib 2, as is the case in the past. Further, due to this manual twisting, there is no need for the process of lowering the boom 1 to a position where the tip of the jib can be reached.

(e) In this way, jib 2 moves from the state shown in Figure 2 to the third position.
It is further twisted approximately 270 degrees to the state shown in FIGS. 4 and 5, and the long piece of the right jib foot 22 hits the right jib mounting shaft 12.

At this time, the left jib foot 21 is located directly below the main attachment portion 11a of the left jib attachment shaft 11.

(F) Lower the auxiliary hook F suspended from the auxiliary winding wire rope W and hang it on the hook hook 7 (state shown in Figs. 4 and 5).

(G) In this state, when the auxiliary winding wire rope W is wound up (normally, the boom 1 is extended with the same rope fixed), the pulling force causes the connecting body 4
The jib 2 is pulled up while the rod (rod 41) is moving backward, and the left jib foot 21 is attached to the left jib mounting shaft 1.
The right jib foot 22 engages with the right jib attachment shaft 12 in the main attachment portion 11a of No. 1 (the sixth
state). In this state, the jib feet 21 and 22
and the connecting body 4 are arranged coaxially.

(H) When the auxiliary winding wire rope W is further wound up, the jib 2 is pulled forward about the jib attachment shafts 11 and 12, and at the same time, the boom 1 is lowered almost horizontally, resulting in the state shown in FIG. 7. In this state, insert the fixing pins (not shown) into the pin holes 21a, 22a of both side jib feet 21, 22, respectively, and fix both side jib feet 21, 22.
are fixed to the jib mounting shafts 11 and 12.

(li) Install the suspension rod S between the jib 2 and the tip of the boom, as shown by the imaginary line in Figure 7. Further, the auxiliary hook F is removed from the hook hanging device 7 and set in a predetermined position as shown by the imaginary line A in FIG. The hook hanging device 7 is stored on the back (lower surface) side of the jib.

With the above steps, the extension of the jib 2 is completed.

Jib stowage Jib stowage is performed by almost the reverse procedure of the above-mentioned extension.

To summarize the main points, with the boom 1 laid down almost horizontally, the auxiliary hook F is engaged with the tip of the jib as shown by the imaginary line B in Fig. 7, unlike when it is extended, to support the jib 2. In this state, remove the suspension rod S.

Also, the connecting body 4 is removed from the auxiliary attachment part 11b of the left jib attachment shaft 11, and as in the case of extension, the operator manually operates to rotate it in the opposite direction to the direction of extension, and the second spring 6 is attached to the second spring 6 when the jib is retracted. After accumulating the torsional force, the connecting body 4 is connected to the auxiliary attachment part 11b again. Also, remove the left and right jib foot fixing pins.

Next, the auxiliary winding wire rope W is loosened to allow the jib 2 to hang down as shown in FIG. During this time, the second spring 6
A clockwise rotation force of is applied to jib 2, but jib 2
is restrained by the tensile force of the auxiliary winding wire rope W, so that rotation can be stopped until the drooping is completed. After the jib is lowered, when the auxiliary winding wire rope W is loosened and the auxiliary hook F is removed from the jib tip (when the jib starts to twist), the jib 2 is released.
The spring force accumulated in the second spring 6 automatically twists in the storage direction.

Therefore, even when the jib is stored, the jib must be manually twisted by the operator, allowing continuous work.

In addition, in order to prevent direct contact between the jib 2 and the left side surface of the boom, a stopper may be provided on the tip boom 1B, the jib base, or both.

At this time, the guide roller 26 faces the entrance of the jib guide 3, and by contracting the boom 1, the guide roller 26 enters the jib guide 3 and moves from the inclined groove part 3a to the horizontal groove part 3b. This allows the jib 2 to connect to the connecting body 4 and the left jib mounting shaft 11.
The boom is automatically pulled toward the left side surface of the boom using the connection point with the auxiliary attachment portion 11b as a fulcrum, and enters the retracted state shown in FIG. 1.

In this way, when using this device, the jib 2 can be automatically twisted by the spring force in a hanging state both when the jib is extended and when it is retracted, so the labor burden on the operator is reduced, and (a) There is no need for the operator to get out of the operator's cab to perform the jib twisting operation. (b) Boom 1 must be moved to a position where the jib can be manually rotated.
By eliminating the need for the process of folding down the jib, it is possible to extend and retract the jib continuously, greatly improving work efficiency.

Furthermore, when using the embodiment apparatus, in the jib storage state shown in FIG. 1, the jib lower main girder 2a is located above the rod 41, which is the torsion center axis, by a distance d ₁ . This distance d ₁ compared to the conventional device shown in Publication No. 130883, etc., in which the lower jib foot axis is coaxial with the lower main girder and the twisting center is the center of the lower jib foot.
The entire jib 2 is retracted upward.

That is, by pulling the jib 2 from the hanging state shown in FIG. 2 to the left side of the boom, the jib 2 can be automatically stored in an upper position where it hardly protrudes below the boom. For this reason, forward visibility is good when the crane is running.

Further, according to this embodiment, the connecting body 4 is attached to the jib 4 so as to be able to slide forward and backward, and the connecting body 4 projects from the jib feet 21 and 22 by a distance d ₂ toward the base end of the jib, or vice versa. Jibft 2
1 and 22 are located closer to the base end of the boom than the jib mounting shafts 11 and 12, so that the jib is pulled and stored with the jib foot engaged with the jib mounting shaft. In comparison, the jib 2 is retracted (shifted back) to the rear position.
Therefore, during crane work with the jib retracted, as the jib 2 is shifted back as described above, the center of gravity of the boom shifts toward the base end of the boom, reducing the overturning moment, which increases the crane capacity. , the front and rear axle loads are well balanced due to the boom weight when traveling.

Note that the connecting body 4 may be left in the advanced state shown in FIG. 1 etc. after the jib is retracted; however,
Normally, it is moved backward and removed from the jib mounting shaft 11.

Other Embodiments (a) In the above embodiment, the connecting body 4 is formed into a bifurcated shape, but the connecting body 4 may be formed into a ring shape as shown in FIG. 13. In this case, as a means for removably connecting the ring-shaped connecting body 4 to the jib attachment shaft 11, in the embodiment shown in FIG. This auxiliary attachment part 11
b through the ring-shaped connecting body 4 to the main attachment part 11a.
A means is taken to fit it externally and connect it with a pin 11c. According to this configuration, by removing the auxiliary attachment part 11b when the jib is not in use,
Since the protrusion of the mounting shaft 11 from the side surface of the boom tip can be small, it is advantageous for crane work when the boom 1 enters into narrow spaces.

(b) In the embodiment shown in FIG.
The length of the auxiliary attachment portion 11b of the left jib attachment shaft 11 can be reduced by bending the side portion on the side of the connecting body 4 of 1 into a crank shape. Note that this configuration can also be adopted in an embodiment in which the ring-shaped connecting body 4 shown in FIG. 13 is used and the main attachment part 11a and the auxiliary attachment part 11b of the jib attachment shaft 11 are configured separately. .

(c) In the embodiment shown in FIGS. 15 and 16, the connecting body of the rod 41 is arranged so that the connecting body 4 is located on the axis of the jib foot 21 in the jib twisted state shown in FIG. The four side ends are bent into a crank shape, and this bent portion including the connecting body 4 is formed by two parallel plates.
In this configuration, when the jib 2 is pulled up after twisting the jib, the upper end surface of the jib foot 21 comes into contact with the lower surface of the bent portion, and this is pushed up, causing the jib foot 21 to engage with the jib mounting shaft 11. .

According to this configuration, there is no need to provide the auxiliary attachment portion 11b on the jib attachment shaft 11, so that the protruding dimension of the attachment shaft 11 can be minimized.

(d) In the embodiment shown in FIGS. 17 and 18,
As a modification of the embodiment configuration in (c) above, when the jib 2 is pulled up after twisting the jib during extension,
The jib foot 21 is the crank part 41 of the rod 41
a, and in the jib extended state, these engaging portions are connected by pins through pin holes 21b and 45. In this configuration, the connecting body 4
This will also function as a jib foot during work.

(e) In the embodiment shown in FIG.
1 is fixed to the jib 2 via a bracket 28, and the connecting body 4 is attached to the end of the rod 41 via a housing 46 so as to be rotatable and slidable about the axis of the rod. In this case, both the first and second springs 5, 6 may be provided by being wound around the rod 41 within the housing 46.

(f) In each of the above embodiments, in order to store the jib 2 at a position above the side of the boom, a connecting body 4 is provided further below the jib lower main girder 2a in addition to the left side jib foot 21, and the left side connecting portion However, as shown in Fig. 20, the left jib foot 21
This is used as the connecting body (left side connecting part) of each of the above embodiments, and is attached to the lower main girder 2a via the rod 8 so as to be rotatable and slidable about the axis of the main girder, and the rod 8 is attached within the main girder 2a. Both first and second springs (not shown) may be wound around the spring.

Further, as a modification of this embodiment, if the shift back function when storing the jib is not required, the rod 8 may be attached only rotatably to the main girder 2a.

(g) As a spring that applies automatic twisting force to jib 2,
A torsion coil spring may be used instead of a spiral spring.

[Effect of idea]

As described above, according to the present invention, a pair of springs are wound in opposite winding directions around the rod of the connection part, which is the center of the jib's twisting when the jib is extended and retracted, and the springs are rotated by the rotation of the rod. Since the jib is configured to automatically twist in the extended direction and the retracted direction in a hanging state by the elastic force of both springs accumulated over time, there is no need for a manual jib twisting device required by an operator as in the case of conventional equipment. becomes.

Therefore, the labor burden on the operator is reduced, and there is no need for the operator to get out of the operator's cab to perform jib twisting operations, and there is no need for the process of once lowering the boom to a position where manual twisting operations can be performed. By making the storage work continuous and reducing the number of man-hours, work efficiency can be greatly improved.

[Brief explanation of drawings]

Figures 1 to 12 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 with the jib pulled up vertically, Figure 7 is a side view with the jib extended, Figure 8 is a partially enlarged view of Figure 1, and Figure 9 is the same. 10 is an enlarged sectional view taken along line A-A in FIG. 8, FIG. 11 is an enlarged cross-sectional view taken along line B-B in FIG. 8, FIG. 12 is a partially enlarged view of FIG. FIG. 14 is a diagram equivalent to FIG. 9 showing another embodiment, FIG. 14 is a diagram equivalent to FIG. 12 showing another embodiment, and FIG.
16 is a view corresponding to FIG. 12, and FIG. 17 is a partially enlarged front view of the stage shown in FIG. 5, showing yet another embodiment. Figure 18 is a diagram equivalent to Figure 12, Figure 1.
FIG. 9 is a diagram corresponding to FIG. 12 showing yet another embodiment;
FIG. 20 is a diagram corresponding to FIG. 1 showing yet another embodiment. 1...Telescopic boom, 11, 12...Jib mounting shaft (shaft body) provided on both left and right sides of the tip of the boom,
2... Jib, 21... Jib foot constituting one of the connecting parts of the jib, 4... The connecting body, 41, 8...
Rod of the connected body, x... Rod axis center, 22...
...Jib foot as the other connection part, 5...1st
Spring, 6...Second spring, 3...Jib guide as a means to stop the jib from twisting until the jib reaches the twisting start position when the jib is extended, 26...The same guide roller, W...The jib starts twisting when the jib is retracted. Auxiliary wire rope as a means of stopping the twisting of the jib until the position is reached, F... Auxiliary hook.

Claims (1)

[Claims for Utility Model Registration] Horizontal shafts on both left and right sides of the tip of the boom, and connecting parts on both sides of the base end of the jib that are detachably connected to the shafts and rotatably connected to the same shafts. one of the connecting parts of the jib has a rod rotatably supported about the longitudinal axis of the jib, and the connecting part with this rod is connected to one of the shafts. In this state, the jib is suspended from the stowed position using this connection point as a fulcrum, then twisted, and then swung forward to extend the jib to the tip of the boom with both side connections connected to both shafts, and vice versa. A crane jib extension and storage device for a crane that is stored on the side of the boom in a procedure, characterized by having the following configuration. () Around the rod of one of the above connection parts,
Both the first and second springs are wound in opposite winding directions. () When the rod rotates in one direction, the first spring accumulates an elastic force in a direction that opposes this rotation, and when the rod rotates in the other direction, no elastic force is accumulated. is fixed to the jib,
The other end must be secured to the rod. () When the rod rotates in the other direction, the second spring accumulates an elastic force in a direction that opposes this rotation, and when the rod rotates in the one direction, no elastic force is accumulated. , one end is fixed to the jib and the other end is locked to the rod. () A means is provided to stop the jib from twisting due to the elastic force of the two springs until the jib reaches the twisting start position when the jib is extended and when the jib is retracted.