JP4613897B2 - Crane jib assembly method and crane jib - Google Patents

Description

  The present invention relates to a crane jib assembling method and a crane jib.

  2. Description of the Related Art Conventionally, a crane including a crane jib composed of a main jib and a supplemental jib connected in order from the crane main body side is known (see, for example, Patent Document 1).

In the crane described in the prior art section of Patent Document 1, the auxiliary jib (tower jib) is connected to the tip of the main jib (tower boom) provided on the crane main body so as to be raised and lowered by a connecting pin. Yes. In this crane, when assembling the main jib and the auxiliary jib, the auxiliary jib is laid on the ground so that the tip side thereof faces the crane body side, and the leading end of the main jib is provided by the strut provided at the leading end of the main jib. Is lifted from the ground and disposed above the proximal end of the auxiliary jib, and in this state, the distal end of the main jib and the proximal end of the complementary jib are connected.
JP-A-5-186187

  In the above-described conventional crane, when the base end of the auxiliary jib is connected to the tip of the main jib lifted from the ground, the base end of the auxiliary jib is lifted by an auxiliary crane or the like to complement the pin hole of the main jib. After aligning the pin holes of the jib so as to be in communication with each other, the connecting work is performed by connecting the main jib and the auxiliary jib by inserting the connecting pins into these pin holes.

  However, when performing the connecting work in such a procedure, the pin hole of the main jib and the pin hole of the auxiliary jib are positioned while finely adjusting the position and inclination of the auxiliary jib, which is a heavy object, in the vertical and horizontal directions. It is necessary to match, and such work requires a lot of labor. For this reason, the work burden in this alignment work becomes very large. In addition, when performing the connecting operation according to the above procedure, since the distal end side of the auxiliary jib is grounded with the proximal end portion of the auxiliary jib being lifted, the auxiliary jib can be freely moved in any direction in this state. It is difficult to move. For this reason, it becomes difficult to accurately align the pin hole of the auxiliary jib with the pin hole of the main jib, and as a result, a slight shift may remain in the positions of both pin holes after the alignment operation. If the displacement remains in this way, it will be difficult to smoothly insert the connecting pin into both pin holes, so when inserting the connecting pin into both pin holes, the tip of the main jib that will be high In addition, a large amount of labor is required, for example, a large number of workers gather and forcefully drive the connecting pin with a large hammer. For this reason, the work burden in the insertion work of a connecting pin becomes very big. Therefore, when the connecting work is performed according to the procedure as described above, there is a problem that the work load in the connecting work becomes very large.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce the work load in the connecting operation of the main jib and the auxiliary jib.

In order to achieve the above object, the crane jib assembly method according to the present invention is characterized in that the auxiliary jib is inserted by inserting connecting pins into pin holes respectively provided at the distal end of the main jib and the proximal end of the auxiliary jib. there a method of assembling a crane jib for connecting the auxiliary jib with undulating freely the main jib and the connecting pin as an axis with respect to the main jib, bottom and of the auxiliary jib tip of the main jib A positioning hole is provided at an upper portion of the base end portion at an equal distance from each of the pin holes, and an insertion hole that is larger than the positioning hole is provided in one of the main jib and the auxiliary jib. It is provided so as to be continuous with the positioning hole, and when connecting the auxiliary jib to the main jib, the base end of the auxiliary jib placed on the ground and the tip of the main jib are aligned, The tip of the complementary jib The main jib is arranged above the auxiliary jib as in the direction towards the proximal end portion of the main jib along the lower side of the main jib, by lifting the base end portion of the auxiliary jib in this state, the The positioning hole and the insertion hole are aligned, the positioning pin is inserted into both, and then the lifting end of the auxiliary jib is released to lower the proximal end portion of the auxiliary jib so that the positioning pin is inserted into the insertion hole. To the continuous positioning hole, and in this state, the tip of the auxiliary jib is lifted to rotate the auxiliary jib around the positioning pin, and the pin hole of the main jib and the auxiliary jib The pin holes are aligned, and in this state, the connecting pins are inserted into both pin holes to connect the main jib and the auxiliary jib.

  In this crane jib assembly method, an insertion hole that is larger than the positioning hole is provided in one of the main jib and the auxiliary jib so as to continue to the positioning hole, and when the auxiliary jib is connected to the main jib, Alignment of the other positioning hole of the main jib and auxiliary jib with the insertion hole and insertion of the positioning pin through both of them makes the insertion work of the positioning pin easier because the insertion hole is larger than the positioning hole Can be done. Moreover, after inserting the positioning pin into the insertion hole and the positioning hole, the lifting of the auxiliary jib is released, so that the base end of the auxiliary jib is lowered by its own weight, and the positioning pin naturally fits in the positioning hole. Both positioning holes can be accurately aligned via the positioning pins. For this reason, since the positioning holes can be accurately aligned by roughly aligning the insertion holes and positioning holes that are widely opened and inserting the positioning pins, the work load in the positioning work of both positioning holes Can also be reduced. In addition, since the main jib and the auxiliary jib are provided with positioning holes at positions equidistant from the respective pin holes, the positioning pins inserted into both positioning holes when connecting the auxiliary jib to the main jib If the auxiliary jib is rotated around the axis, the pin hole of the main jib and the pin hole of the auxiliary jib can be easily aligned. In other words, the main jib pin hole and the auxiliary jib pin hole can be aligned only by adjusting only the vertical position of the base end portion of the auxiliary jib by lifting the tip of the auxiliary jib. Therefore, unlike the conventional case where the auxiliary jib is simply lifted to align both pin holes, both pin holes can be aligned without manually adjusting the position and inclination of the auxiliary jib in the horizontal direction. Therefore, the work load in the alignment work of both pin holes can be reduced accordingly. Further, in this crane jib assembly method, the main jib and the auxiliary jib are each provided with positioning holes at equidistant positions from the respective pin holes, and when connecting the auxiliary jib to the main jib, By lifting the tip of the auxiliary jib, the auxiliary jib is rotated around the positioning pin inserted into both positioning holes to align the pin hole of the main jib and the pin hole of the auxiliary jib. The pin hole of the main jib and the pin hole of the auxiliary jib can be accurately aligned with reference to the positioning pin inserted through the pin. As a result, the connecting pins can be smoothly inserted into both pin holes, so that it is difficult for many workers to gather at high places and force the connecting pins into the pin holes with a large hammer as in the past. The connecting pin can be easily inserted into both pin holes without performing the above. For this reason, the work burden in the insertion work of a connection pin can be reduced. Therefore, in this crane jib assembling method, it is possible to reduce the work load in the connecting work of the main jib and the auxiliary jib.

In the crane jib according to the present invention, pin holes are respectively provided in a lower portion of the front end portion of the main jib and an upper portion of the base end portion of the auxiliary jib, and the connecting pin is inserted into each pin hole, whereby the auxiliary jib is inserted into the main jib. A main jib and a supplemental jib that are connected to the jib in an up-and-down manner with the connection pin as an axis, and the lower end of the front end of the main jib and the upper end of the base end of the auxiliary jib Positioning holes arranged at equidistant positions from the holes are respectively provided, and positioning pins inserted through the positioning holes are provided so as to be insertable / removable. One of the main jib and the auxiliary jib is provided with the positioning hole And an insertion hole that is larger than the positioning hole is provided, and the insertion hole aligns the position of the base end portion of the auxiliary jib placed on the ground with the tip end portion of the main jib, and The tip of the main jib When placed the main jib above the auxiliary jib along the lower side of the main jib in the direction towards the base end portion connecting said auxiliary jib to the main jib, a base end portion of the auxiliary jib The positioning pin inserted into the positioning hole provided in the other of the main jib and the auxiliary jib is insertable, and the lifting of the proximal end of the auxiliary jib is released In this state, the positioning pin in the insertion hole is configured to be movable to a positioning hole continuous with the insertion hole, and the auxiliary jib can be rotated about the positioning pin moved into the positioning hole. ing.

  In this crane jib, one of the main jib and the auxiliary jib is provided with an insertion hole that is continuous with the positioning hole and is larger than the positioning hole, and the insertion hole can be inserted with a positioning pin. Therefore, when positioning the other positioning hole of the main jib and the auxiliary jib to the insertion hole and inserting the positioning pin into both, the insertion hole is larger than the positioning hole, so that the positioning pin The insertion operation can be easily performed. Moreover, after the positioning pin is inserted into the insertion hole and the positioning hole, the positioning pin in the insertion hole can be moved to the positioning hole continuous with the insertion hole in a state where lifting of the proximal end portion of the auxiliary jib is released. Since the insertion hole is configured, after the positioning pin is inserted into the insertion hole and the positioning hole, the base end of the auxiliary jib is lowered by its own weight in the state where lifting of the base end of the auxiliary jib is released. The pins naturally fit in the positioning holes, and as a result, the positioning holes can be accurately aligned via the positioning pins. For this reason, since the positioning holes can be accurately aligned by roughly aligning the insertion holes and positioning holes that are widely opened and inserting the positioning pins, the work load in the positioning work of both positioning holes Can also be reduced. In addition, the main jib and the auxiliary jib each have a positioning hole through which the positioning pin is inserted at a position equidistant from each pin hole, and the auxiliary jib rotates around the positioning pin in the positioning hole. Because it is possible, when connecting the auxiliary jib to the main jib, if the auxiliary jib is rotated around the positioning pin inserted into both positioning holes, the pin hole of the main jib and the pin hole of the auxiliary jib Can be easily aligned. In other words, the main jib pin hole and the auxiliary jib pin hole can be aligned only by adjusting only the vertical position of the base end portion of the auxiliary jib by lifting the tip of the auxiliary jib. For this reason, similarly to the above, it is possible to reduce the work load in the alignment work of both pin holes. In this crane jib, the main jib and the auxiliary jib are each provided with a positioning hole through which a positioning pin is inserted at an equal distance from each pin hole, and the auxiliary jib is positioned in the positioning hole. Since the pin can be rotated around the axis, when the auxiliary jib is connected to the main jib, the auxiliary jib is rotated around the positioning pin inserted into the positioning holes as an axis to complement the pin hole of the main jib. If the pin holes of the jib are aligned, the pin holes of the main jib and the pin holes of the auxiliary jib can be accurately aligned with reference to the positioning pins inserted into both positioning holes. Thereby, since a connection pin can be smoothly inserted in both pin holes, the work burden in the insertion operation of a connection pin can be reduced like the above. Therefore, in this crane jib, it is possible to reduce the work load in the connecting work of the main jib and the auxiliary jib.

  As described above, according to the present invention, it is possible to reduce the work load in the connecting work of the main jib and the auxiliary jib. In addition, since it is not necessary to drive the connecting pin with a large hammer at a high place, work safety is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a state of assembling a crane attachment 2 (crane jib) according to an embodiment of the present invention. FIG. 2 shows a tower boom 21 and a tower jib 22 constituting the crane attachment 2. The structure of the connecting portion is partially shown. The tower crane by this embodiment is provided with the crane main body 1, the crane attachment 2, and the strut 3, as shown in FIG.

  The crane body 1 includes a crawler-type lower traveling body 1a and an upper revolving body 1b that is rotatably mounted on the lower traveling body 1a.

  The crane attachment 2 is configured by sequentially connecting a tower boom 21 (main jib) and a tower jib 22 (auxiliary jib) from the crane body 1 side. The base end portion of the tower boom 21 is attached to the front portion of the upper swing body 1 b, and is configured to be raised and lowered with respect to the crane body 1. Note that the tower crane is configured to perform the hanging work in a state where the tower boom 21 is raised to a substantially vertical position. A tower cap 21a is provided at the distal end of the tower boom 21 (the end opposite to the crane body 1), and the base end 22a of the tower jib 22 is connected to the tower cap 21a so as to be raised and lowered. The tower jib 22 is positioned below the tower boom 21 in a state where the tower boom 21 is laid down, and moves up and down on the front side (opposite side of the crane body 1) of the tower boom 21 when the tower boom 21 is upright. It is configured.

  As shown in FIG. 2, a pin hole 21b is provided at the distal end portion of the tower cap 21a, and a base end portion 22a of the tower jib 22 is provided as a specific configuration of the connecting portion between the tower boom 21 and the tower jib 22. A pin hole 22b is provided. The connecting pin 23 is inserted into the pin holes 21b and 22b to connect the tower cap 21a of the tower boom 21 and the base end portion 22a of the tower jib 22, and the tower jib 22 is connected to the tower boom with the connecting pin 23 as an axis. 21 can be raised and lowered freely. Further, the tower jib 22 is configured by connecting a proximal end side jib constituent member 32a, a plurality of intermediate jib constituent members 32b, and a distal end side jib constituent member 32c in order from the tower cap 21a side.

  In the present embodiment, the bracket 21c is welded to the lower portion of the tower cap 21a with the tower boom 21 and the tower jib 22 lying down, while the bracket 22c is welded to the upper portion of the base end portion 22a of the tower jib 22. Yes. The bracket 21c may be fastened to the tower cap 21a by bolts and nuts instead of welding, and the bracket 22c may also be fastened to the tower jib 22 by bolts and nuts instead of welding.

  The bracket 21c on the tower boom 21 side is provided with a positioning hole 21d and an insertion hole 21e that opens larger than the positioning hole 21d. The positioning hole 21d and the insertion hole 21e are opened to a size that allows the positioning pin 24 to be inserted. In the insertion hole 21e, the opening width along the length direction of the tower boom 21 and the opening width in the vertical direction are both larger than the corresponding opening width of the positioning hole 21d, and the opening area of the insertion hole 21e is as follows. It is larger than the opening area of the positioning hole 21d. And the insertion hole 21e is provided so that it may continue on the upper side of the positioning hole 21d in the state in which the tower boom 21 was laid down, and the positioning hole 21d was formed in the diameter corresponding to the pin diameter of the positioning pin 24. It is configured in a semicircular shape. The bracket 22c on the tower jib 22 side is provided with a circular positioning hole 22d having a diameter corresponding to the pin diameter of the positioning pin 24, and the positioning pin 24 can be inserted into the positioning hole 22d.

  The positioning hole 21d and the positioning hole 22d are located at positions where the distance from the pin hole 21b of the positioning hole 21d on the tower boom 21 side and the distance from the pin hole 22b of the positioning hole 22d on the tower jib 22 side are equal. Is provided. A positioning pin 24 is inserted into the positioning holes 21d and 22d when the tower jib 22 is connected to the tower cap 21a of the tower boom 21, and a pin on the tower boom 21 side with reference to the inserted positioning pin 24. The holes 21b and the pin holes 22b on the tower jib 22 side can be aligned.

  Moreover, the opening width of the boundary part between the insertion hole 21e and the positioning hole 21d is larger than the diameter of the positioning pin 24, and the positioning pin 24 can move from the insertion hole 21e to the positioning hole 21d. When the positioning pin 24 is inserted into the positioning hole 21d on the tower boom 21 side and the positioning hole 22d on the tower jib 22 side, the positioning hole 22d of the tower jib 22 and the tower boom are in a state where the tower boom 21 and the tower jib 22 are lying down. After aligning the insertion hole 21e on the 21st side and inserting the positioning pin 24 into both, the base end portion 22a of the tower jib 22 is lowered to lower the positioning pin 24 from the insertion hole 21e to the continuous positioning hole 21d. Thus, the positioning pins 24 are inserted into the positioning holes 21d and 22d.

  The procedure at the time of assembling the crane attachment 2 by this embodiment is shown by FIGS. Next, with reference to FIGS. 3-12, the assembly method of the crane attachment 2 by this embodiment is demonstrated.

  In the present embodiment, as shown in FIG. 3, first, a mark M1 indicating the center position of the pin hole 21b of the tower cap 21a is written on the ground in a state in which the tower boom 21 is tilted. A mark M2 (see FIG. 5) indicating the position is marked on the ground. Thereafter, the strut 3 is raised until it leaves the ground.

  Next, the tower boom 21 is raised at a low speed, and the tower boom 21 is raised to a position where the elevation angle is about 20 ° as shown in FIG. Thereafter, as shown in FIG. 5, a space for assembling the tower jib 22 is created by turning the upper turning body 1 b in the horizontal direction by about 20 °.

  Next, as shown in FIG. 6, the base end side jib constituting material 32a constituting the tower jib 22 is placed on the ground in accordance with the marks M1 and M2 (see FIG. 5) previously written on the ground. At this time, the base end side jib constituent member 32a is placed on the ground with the surface on which the bracket 22c is provided facing up, the center position of the pin hole 22b is aligned with the mark M1, and the base end side jib constituent member 32a in the width direction. The center position is adjusted to the mark M2.

  Thereafter, as shown in FIG. 7, the intermediate jib component 32b is connected to the proximal jib component 32a based on a predetermined configuration table, and the end of the intermediate jib component 32b on the crane body 1 side is connected to the distal end side. The tower jib 22 is assembled by connecting the jib components 32c.

  Next, as shown in FIG. 8, the upper swing body 1 b is turned in the horizontal direction and returned to the original position, and the center position in the width direction of the tower boom 21 and the center position in the width direction of the tower jib 22 are matched. Thereafter, the strut 3 that has been raised is lowered and the tower boom 21 is lowered at a low speed. And as shown in FIG. 9, the strut 3 supports the front-end | tip part of the tower boom 21 in the state lifted from the ground. In this way, the tower boom 21 is arranged above the tower jib 22 along the tower jib 22 placed on the ground.

  Next, in the present embodiment, as shown in FIG. 10, the auxiliary crane 100 lifts the base end portion 22a side of the tower jib 22 so that the positioning hole 22d on the tower jib 22 side and the tower boom 21 side are shown in FIG. The insertion hole 21e is aligned. Then, as shown in FIG. 12, the positioning pin 24 is inserted into the positioning hole 22d and the insertion hole 21e. As shown in FIG. 12, a pair of brackets 21c formed with insertion holes 21e are provided at a predetermined interval, and the bracket 22c of the tower jib 22 is inserted between the pair of brackets 21c and 21c for positioning and positioning. The positioning pin 24 is inserted through the hole 22d and the insertion hole 21e.

  Then, after the positioning pin 24 is inserted into the positioning hole 22d and the insertion hole 21e, the washer 24a is fitted to the end of the positioning pin 24 on the insertion side to the positioning hole 22d and the insertion hole 21e. Then, the positioning pin 24 is prevented from coming off by inserting the lock pin 24c into a through hole 24b provided so as to penetrate the end of the positioning pin 24 outside the washer 24a in the radial direction.

  Thereafter, the lifting of the tower jib 22 on the base end portion 22a side by the auxiliary crane 100 is released, and the tip end portion 22f of the tower jib 22 is hung by the auxiliary crane 101 as shown in FIG. And the positioning pin 24 is lowered from the insertion hole 21e to the continuous positioning hole 21d.

  When the alignment between the insertion hole 21e and the positioning hole 22d of the tower jib 22 is slightly shifted, the positioning pin 24 is caught by the convex portion 21f (see FIG. 11) at the boundary between the insertion hole 21e and the positioning hole 21d. In this case, the tip 22f of the tower jib 22 is moved up and down by the auxiliary crane 101, and the positioning pin 24 hooked by the projection 21f (see FIG. 11) is lowered to the positioning hole 21d. . In this manner, the positioning hole 21 d on the tower boom 21 side and the positioning hole 22 d of the tower jib 22 are aligned via the positioning pins 24.

  Next, in this state, the auxiliary crane 101 lifts the tip end portion 22f side of the tower jib 22 to rotate the tower jib 22 around the positioning pin 24, and as shown in FIG. 2, the pin hole 21b of the tower cap 21a and the tower jib The 22 pin holes 22b are aligned. At this time, the distance between the positioning hole 21d on the tower boom 21 side and the pin hole 21b and the distance between the positioning hole 22d on the tower jib 22 side and the pin hole 22b are equal. Due to this, the pin hole 21b on the tower boom 21 side and the pin hole 22b on the tower jib 22 side are accurately aligned.

  In this state, the tower cap 21a of the tower boom 21 and the tower jib 22 are connected by inserting the connecting pin 23 into both the pin holes 21b and 22b. In addition, when inserting the connecting pin 23 into both the pin holes 21b and 22b, since the positions of both the pin holes 21b and 22b are accurately aligned, the connecting pin 23 can be smoothly inserted into the both pin holes 21b and 22b. In this insertion work, one operator can easily drive the connecting pin 23 into both the pin holes 21b and 22b using a small hammer. As described above, the crane attachment 2 according to the present embodiment is assembled.

  As described above, in the present embodiment, the insertion hole 21e that is larger than the positioning hole 21d is provided on the tower boom 21 side so as to continue to the positioning hole 21d, and the tower jib 22 is connected to the tower boom 21. When positioning, the positioning hole 22d of the tower jib 22 is aligned with the insertion hole 21e, and the positioning pin 24 is inserted through the positioning hole 24e. Therefore, the insertion hole 21e is larger than the positioning hole 21d and the positioning pin 24 The insertion operation can be easily performed. Moreover, after the positioning pin 24 is inserted into the insertion hole 21e and the positioning hole 22d, the lifting of the tower jib 22 on the base end 22a side is released, so that the base end 22a of the tower jib 22 is lowered by its own weight, and the positioning pin 24 Naturally fits in the positioning hole 21d, and as a result, the positioning holes 21d and 22d can be accurately aligned via the positioning pin 24. For this reason, the positioning holes 21d and 22d can be accurately aligned only by roughly aligning the insertion hole 21e and the positioning hole 22d which are widely opened and inserting the positioning pin 24. , 22d can be reduced in work load.

  In the present embodiment, the tower boom 21 and the tower jib 22 are provided with positioning holes 21d and 22d at positions equidistant from the pin holes 21b and 22b, respectively, so that the tower jib 22 is connected to the tower boom 21. When the tower jib 22 is rotated about the positioning pin 24 inserted into the positioning holes 21d and 22d, the pin hole 21b of the tower boom 21 and the pin hole 22b of the tower jib 22 are easily aligned. be able to. That is, by lifting only the front end portion 22f of the tower jib 22 and adjusting only the vertical position of the base end portion 22a of the tower jib 22, the pin hole 21b of the tower boom 21 and the pin hole 22b of the tower jib 22 are aligned. be able to. Therefore, unlike the conventional case where the tower jib 22 is simply lifted to align the pin holes 21b and 22b, the pin holes 21b and 22b are not adjusted manually by adjusting the horizontal position and inclination of the tower jib 22. Therefore, the work load in the alignment work of the pin holes 21b and 22b can be reduced accordingly.

  In the present embodiment, the tower boom 21 and the tower jib 22 are provided with positioning holes 21d and 22d at equal distances from the pin holes 21b and 22b, respectively, and the tower jib 22 is connected to the tower boom 21. When the tower jib 22 is lifted, the tower jib 22 is pivoted around the positioning pin 24 inserted into the positioning holes 21d and 22d, and the pin hole 21b of the tower boom 21 and the pin of the tower jib 22 are lifted. By aligning the holes 22b, the pin holes 21b of the tower boom 21 and the pin holes 22b of the tower jib 22 can be accurately aligned with reference to the positioning pins 24 inserted into the positioning holes 21d and 22d. . Thereby, since the connection pin 23 can be smoothly inserted into both the pin holes 21b and 22b, the work load in the insertion work of the connection pin 23 can be reduced. Therefore, in the method for assembling the crane attachment 2, it is possible to reduce the work burden in the connecting work between the tower boom 21 and the tower jib 22.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, in the above-described embodiment, the insertion hole 21e is provided so as to be continuous with the positioning hole 21d on the tower boom 21 side. However, the present invention is not limited to this, and the insertion hole 21e is continuous with the positioning hole 22d on the tower jib 22 side. A large opening may be provided. In this case, the insertion hole is provided so as to be continuous with the lower side (tower jib 22 side) in FIG. 2 of the positioning hole 22d. In this case, after the positioning pin 24 is inserted into the insertion hole and the positioning hole on the tower boom 21 side, the positioning end 24a is not moved by lowering the proximal end portion 22a of the tower jib 22, but from the insertion hole. The continuous positioning hole 22d descends, and the positioning pin 24 naturally fits in the positioning hole 22d.

  Moreover, although the said embodiment demonstrated the example which applied this invention to the crane attachment 2 of the tower crane which suspends the tower boom 21 in the state which stood up substantially perpendicularly, it is not restricted to this, Other than a tower crane It is also possible to apply the present invention to a crane attachment of a type of crane. For example, the present invention can be applied to a crane attachment or the like of a luffing crane that suspends a tower jib with a predetermined elevation angle.

It is the side view which showed the state at the time of assembling the crane attachment of the tower crane by one Embodiment of this invention. It is the figure which showed partially the structure of the connection part of the tower boom and tower jib which comprise the crane attachment of the tower crane shown in FIG. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is the figure which looked at the tower crane for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention from upper direction. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is the figure which looked at the tower crane for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention from upper direction. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is a figure for demonstrating the procedure at the time of assembling the crane attachment by one Embodiment of this invention. It is the figure which showed partially the structure of the connection part of the tower boom and tower jib which comprise the crane attachment shown in FIG. It is sectional drawing along the XII-XII line of the tower cap and tower jib of the tower boom shown in FIG.

Explanation of symbols

21 Tower Boom (Main Jib)
22 Tower jib (supplementary jib)
21b, 22b Pin hole 23 Connecting pin 2 Crane attachment (crane jib)
21d, 22d Positioning hole 21e Insertion hole

Claims (2)

By inserting a connecting pin into pin holes respectively provided at the distal end of the main jib and the proximal end of the auxiliary jib, the auxiliary jib can be raised and lowered with the connecting pin as an axis relative to the main jib. And an assembly method of a crane jib for connecting the auxiliary jib and
A positioning hole is provided at a position equidistant from each pin hole at the lower part of the front end part of the main jib and the base end part of the auxiliary jib, and one of the main jib and the auxiliary jib is provided. Is provided such that an insertion hole that is larger than the positioning hole is continuous with the positioning hole,
When connecting the auxiliary jib to the main jib, the base end of the auxiliary jib placed on the ground is aligned with the front end of the main jib, and the front end of the auxiliary jib is the base end of the main jib The main jib is arranged above the auxiliary jib so as to be along the lower side of the main jib in a direction toward the part ,
In this state, by lifting the proximal end portion of the auxiliary jib, the positioning hole and the insertion hole are aligned, a positioning pin is inserted into both, and then the auxiliary jib is lifted to release the auxiliary jib. Moving the positioning pin from the insertion hole to the positioning hole continuous by lowering the base end of
In this state, by lifting the tip of the auxiliary jib, the auxiliary jib is rotated about the positioning pin as an axis to align the pin hole of the main jib and the pin hole of the auxiliary jib, and this state A method for assembling a crane jib, wherein the main jib and the auxiliary jib are connected by inserting the connecting pin into both pin holes. Pin holes are provided in the lower part of the front end part of the main jib and the upper part of the base end part of the auxiliary jib, and the connecting pin is inserted into each pin hole so that the auxiliary jib is connected to the main jib. It has a main jib and a supplemental jib that are connected up and down as a shaft ,
Positioning holes arranged at equal distances from the respective pin holes are provided in the lower part of the front end part of the main jib and the upper part of the base end part of the auxiliary jib , and are inserted through these positioning holes. Positioning pins are provided so that they can be inserted and removed.
One of the main jib and the auxiliary jib is provided with an insertion hole that is continuous with the positioning hole and opens larger than the positioning hole.
The insertion hole aligns the base end of the auxiliary jib placed on the ground and the tip of the main jib, and the main jib extends in a direction toward the base end of the main jib. the auxiliary jib by arranging the main jib above the auxiliary jib along the lower side when connected to the main jib, in a state of lifting the base end portion of the auxiliary jib, the main jib and The positioning pin in the insertion hole is configured so that the positioning pin inserted into the positioning hole provided on the other side of the auxiliary jib can be inserted, and the lifting of the proximal end portion of the auxiliary jib is released Is configured to be movable to a positioning hole continuous with the insertion hole,
The auxiliary jib is a crane jib that is rotatable about a positioning pin that has moved into the positioning hole.

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