JP4811896B2 - Tower crane jib fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a jib fixing device for a tower crane used in a high-rise building or the like.
[0002]
[Prior art]
Among the tower cranes, the mobile tower crane is an upper revolving structure in which a main winding drum 3, an auxiliary winding drum 4, and an undulation drum 5 are mounted on a lower traveling body 1 as shown in FIG. A certain crane body 2 is mounted, and on the crane body 2, the base end portion of the post 7 as a skeleton structure is attached in a undulating manner with four cord pipes and a connecting material for connecting them, and the post 7 One end of the post support rope 6 is attached to the tip, the other end of the post support rope 6 is attached to the equalizer 9, and between the equalizer 9 and the yoke 11 of the A frame 10 erected on the crane body 2. The hoisting rope 12 fed from the hoisting drum 5 is hung around the hoisting drum 5 so that the post 7 can be hoisted by winding and unwinding the hoisting rope 12. The base end portion of the tower jib 8 that is a frame structure is connected to the pipe pipe and a connecting material for connecting them, and the main winding rope 13 fed from the main winding drum 3 is guided to the tip end portion of the tower jib 8. A load hanging hook (not shown) provided on the tip end side of the tower jib 8 so as to be movable up and down is suspended by the main winding rope 13 and the tower jib 8 is lifted around a connection point to the post 7. Therefore, one apex angle portion of the triangular strut 14 is swingably attached to the tip end portion of the post 7, and the front apex angle portion of the other two apex angles of the strut 14 is The top end of the tower jib 8 is connected with a support rope 15, and one end of the strut support rope 16 is attached to the apex portion on the rear side of the strut 14, and the other end of the strut support rope 16 is connected to the middle. It is attached to the collizer 17, and the auxiliary rope 19 fed from the auxiliary winding drum 4 is hung between the middle equalizer 17 and the middle yoke 18, and the post 7 is placed on the undulating drum 5 on the crane body 2. The tower jibb 8 is raised and lowered by the auxiliary rope 19 wound around the auxiliary winding drum 4 via the strut 14 while being raised and lowered by the wound up and down rope 12.
[0003]
Also, in this type of tower crane, when the post 7 is tilted down to the ground or when the post 7 is lifted from the ground, the jib is fixed so that both can be fixed with the tower jib 8 folded to the post 7 side. The device 20 is equipped.
[0004]
As shown in FIG. 5 and FIG. 6, the jib fixing device 20 includes a cord pipe 8 a that is positioned on the post side when folded among the plurality of cord pipes 8 a that constitute the tower jib 8, and a tip side that is on the post 7 side. A support plate 24 is attached so as to protrude, and a latch bar 25 is attached to the front end portion of the support plate 24 in a right angle direction. On the other hand, a plurality of cord pipes 7a constituting the post 7 are placed on the folded tower jib 8 side. A support plate 27 is horizontally attached toward the opposite side of the tower pipe jib 8 of the cord pipe 7a, and a support shaft 28 is attached to the support plate 27 in parallel with the latch bar 25. The latch plate 26 has a latch pawl 26a that can be engaged with the latch bar 25 and a notch 26b is provided on the lower side of the central portion. In addition, one end of the jib detection lever 31 is attached to a required portion of the outer surface of the base end side of the latch plate 26 so as to be rotatable by a shaft 32, and one end of the jib detection lever 31 and the latch plate 26 are The spring 29 is interposed between the base end and the upper position so that the jib detection lever 31 is always rotated downward by the spring 29 until the latch plate 26 is engaged with the latch bar 25. 5, the jib detection lever 31 is in a standby position where it overlaps with the notch 26 b as shown by a solid line in FIG. 5, the latch plate 26 is engaged with the latch bar 25, and the latch bar 25 is notched in the latch plate 26. 26b, the jib detection lever 31 is rotated counterclockwise in FIG. 5 and displaced to the engagement position indicated by the two-dot chain line. Furthermore, the jib detection lever 31 is attached to one end of the jib detection lever 31 when the jib detection lever 31 is displaced to the position indicated by the two-dot chain line on the outer side surface of the latch plate 26 on the base end side. The limit switch 30 is attached to the striker piece 33 so that the operation piece 30a is pushed to operate, and the engagement between the latch plate 26 and the latch bar 25 can be confirmed by the operation of the limit switch 30. (Japanese Patent Laid-Open No. 10-17276).
[0005]
Reference numerals 34 and 35 denote stoppers that restrict the rotational displacement of the jib detection lever 31.
[0006]
[Problems to be solved by the invention]
However, in the case of the jib fixing device 20 shown in the above-mentioned JP-A-10-17276, the limit switch 30 which is a precision instrument is attached to the outer surface of the latch plate 26 and is exposed to the outside. There is a problem that the limit switch 30 is likely to cause a breakage accident during handling of the tower crane. That is, at the construction work site, when the work of one day is finished, the post 7 shown in FIG. 4 is parked on the ground with the tower jib 8 folded, but the post 7 and the tower jib 8 are on the ground. In the vicinity where the material lies, the material is transported. Therefore, the transport material or the like may accidentally contact the limit switch 30 attached to the outer surface of the latch plate 26. There is a risk of damage or failure. When transporting the tower crane, the post 7 and the tower jib 8 are usually disassembled. However, the limit switch 30 may be damaged or broken when the post 7 and the tower jib 8 are disassembled, assembled or transported. This may cause
[0007]
Therefore, the present invention is intended to prevent damage to the limit switch and occurrence of failure due to contact with materials, etc., when the post and tower jib are folded in a folded state. is there.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a tower crane jib that is fixedly held in a folded state by a tower jib connected to the tip of the post so that the tower jib can be raised and lowered. In the fixing device, a latch bar is attached to the tower jib so that the tower jib is folded horizontally in a direction intersecting the direction in which the tower jib and the post face each other, and one end side protrudes from the tower jib. A base end portion of a latch plate having a downward notch for engaging with the latch bar is integrally attached to a horizontal support shaft that is rotatably attached to the support shaft, and is supported in a vertically rotatable manner together with the support shaft. is, and on the end side of the latch bar than the latch plate, preparative proximal end pivotably in the vertical direction to the support shaft The jib detection lever attached, and arranged in parallel at a predetermined interval, between the base end of the base end side and the latch plate of the jib detection lever, downward tip side of the jib detection lever A spring is interposed so as to urge the rotation, and a limit switch is attached to the surface on the latch plate side of the jib detection lever between the latch plate and the jib detection lever, and is engaged with the notch. A striker plate for actuating the operating piece of the limit switch when the tip side of the jib detection lever is pushed up by the latch bar , and the jib detection lever of the latch plate between the latch plate and the jib detection lever. It is set as the structure attached to the side surface .
[0009]
Since the limit switch is attached to the latch plate side surface of the jib detection lever between the latch plate and the jib detection lever, the tower jib is folded and fixed while the post is lying down. Even if the material or the like accidentally contacts the jib detection lever, it is possible to prevent the occurrence of an accident that would damage the limit switch.
[0010]
In addition, the limit switch operation piece is positioned on the opposite side of the jib detection lever latch plate through the jib detection lever, and the striker plate is aligned with the limit switch operation piece to latch the jib detection lever. Even if the configuration is extended to the opposite side of the plate, it is possible to avoid damage to the limit switch.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
1 and 2 show an embodiment of the present invention. For the post 7 composed of four front and rear, left and right cord pipes 7a similar to those shown in FIG. 4 and a connecting member for connecting them. Similarly, in order to fix the tower jib 8 composed of four cord pipes 8a, front, rear, left and right, and a connecting material for connecting them, the latch plate on the post 7 side is engaged with the latch bar on the tower jib 8 side. In the tower crane jib fixing device to be fixed, a horizontal support member 8b is attached to the required portion of the tower jib 8 between the left and right cord pipes 8a located on the post 7 side by a U bolt 21, A support plate 37 is attached to the horizontal support member 8b so as to protrude toward the post 7 side, and a latch bar 36 is attached to the support plate 37 from the end of the horizontal support member 8b. The left and right cord pipes 7a located on the tower jib 8 side at the position corresponding to the latch bar 36 on the tower jib 8 side are attached to the post 7 in a horizontal manner so that the end portion protrudes outward in the left-right direction. A horizontal support member 7b is attached to the horizontal support member 7b with a U-bolt 22, and a support plate 39 is attached to the horizontal support member 7b so as to project toward the tower jib 8 side. A base end portion of a latch plate 40 for integrally supporting and releasing the latch bar 36 is integrally attached to the support shaft 38, and the support shaft 38 is vertically attached together with the support shaft 38. It is supported so that it can rotate freely.
[0013]
The latch plate 40 is formed with an engagement guide surface 42 inclined backward at an angle of 45 ° on the front end surface, and a latch claw portion 43 is provided at a lower end portion of the engagement guide surface 42, and a lower side portion. In addition, a U-shaped notch 41 for engaging with the latch bar 36 is formed so as to be continuous with the latch claw portion 43, and on the base end side from an attachment portion to the support shaft 38. In addition, a stopper piece 44 that protrudes rearward from the lower position is provided, and the stopper piece 44 abuts on the lower surface of the horizontal support member 7b, so that the downward rotational displacement due to the entire weight is restricted. It is.
[0014]
Further, a jib detection lever 45 is arranged in parallel with the outer surface of the latch plate 40 at a predetermined distance from the outer surface of the latch plate 40, and the base end portion of the jib detection lever 45 is rotated around the support shaft 38. A bulging portion 46 that projects downward by a required amount is formed at the base end of the jib detection lever 45, and is attached to the bulging portion 46 and the stopper piece 44 of the latch plate 40. A tension spring 48 is interposed between the bracket 47 and the tip end side of the jib detection lever 45 so that the tip end side of the jib detection lever 45 is always rotated downward with the support shaft 38 as a fulcrum. A stopper plate 50 in which a long hole 49 having a required length extending in the width direction is formed at the front end portion is fixed to the outer surface of the outer surface of the jib detection lever 45 so that the long hole 49 is in the vertical direction. Insert the tip Then, the jib detection lever 45 can be rotated between a standby position (dashed line) where the tip of the jib detection lever 45 is lowered to the position of the notch 41 and an engagement position (solid line) located above the notch 41. Like that.
[0015]
Further, the limit switch 30 is attached to the inner surface of the jib detection lever 45, the operating piece 30a of the limit switch 30 is set upward toward the support shaft 38, and the operating piece 30a of the limit switch 30 is mounted. A striker plate 51 for pushing downward is attached to the upper position of the outer surface on the base end side of the latch plate 40 so as to extend horizontally, and the jib detection lever 45 is actuated above the standby position against the force of the tension spring 48. When the latch bar 36 is pushed up to the position (two-dot chain line), the striker plate 51 is brought into contact with the operating piece 30a so that the limit switch 30 is operated.
[0016]
Reference numeral 52 denotes an operation lever for detaching the latch plate 40 from the latch bar 36. An operation rope 53 for guiding the operation rope 53 to the cab side by fixing the base end at a required angle on a support shaft 38 extending in the horizontal direction at a required angle. It is designed to be connected to the tip.
[0017]
When the tower jib 8 is folded to the post 7 side and the post 7 and the tower jib 8 are laid down on the ground side in front of the crane body 2, the latch bar 36 is engaged with the latch plate 40 and fixed. However, in this case, when the tower jib 8 is moved closer to the post 7, the latch bar 36 comes into contact with the engagement guide surface 42 of the latch plate 40, so that the stopper piece 44 contacts the lower surface of the horizontal support member 7b. The front end side of the latch plate 40 that is in contact with and is restricted from rotating downward is pushed up with the support shaft 38 as a fulcrum, so that the latch bar 36 is relatively lowered, and the latch claw portion By getting over 43, the notch 41 is engaged. At this time, on the latch plate 40, the jib detection lever 45 in a state in which the distal end side is biased downward by the tension spring 48 is in a standby position where it overlaps the notch 41, and therefore the latch bar 36 is latched by the latch claw portion. 43, the jib detection lever 45 in the standby position is pushed up when it is lifted relative to the latch plate 40, and when the jib detection lever 45 is pushed up from the operating position indicated by the two-dot chain line. The operating piece 30a of the limit switch 30 comes into contact with the striker plate 51 and the limit switch 30 is operated. Accordingly, it can be confirmed by lamp display or the like that the tower jib 8 is folded and fixed to the post 7 based on the operation of the limit switch 30.
[0018]
In the above, since the jib detection lever 45 is configured to be rotatably attached to the support shaft 38 of the latch plate 40, one support shaft 38 can be used effectively, and a dedicated shaft for the jib detection lever 45 needs to be provided separately. Therefore, the configuration can be simplified and the functions can be sufficiently exhibited.
[0019]
By setting the fixed state as described above, it is possible to prevent the tower jib 8 from being inadvertently rotated when the post 7 is tilted forward. Further, when standing up from the lying down state, it can be performed stably in the same manner.
[0020]
In the above-described lying state of the post 7, the jib fixing device is positioned at a height where there is a possibility of contact with materials passing through the side, but the limit switch 30 is located on the inner surface of the jib detection lever 45. Since it is attached and is not exposed on the outer surface, it can be protected from contact with transporting materials and the like, and damage accidents and breakdowns can be prevented. Further, even when the post 7 and the tower jib 8 are disassembled and assembled, it is possible to prevent the limit switch 30 from being damaged. Therefore, it can be used stably for a long time without taking any special measures against damage. Further, since the limit switch 30 is attached to the inner surface of the jib detection lever 45, it is not necessary to secure a mounting space for the limit switch 30 in the latch plate 40, and therefore the latch plate 40 can be downsized. In addition, there is an advantage that the degree of freedom in the shape design of the latch plate 40 can be increased. Furthermore, since the tip of the jib detection lever 45 is guided by the long hole 49 of the stopper plate 50, it can be displaced stably in the vertical direction, and a reliable operation can be obtained.
[0021]
Next, FIG. 3 shows another embodiment of the present invention. In the same configuration as that shown in FIGS. 1 and 2, only the operating piece 30a of the limit switch 30 is attached to the jib detection lever 45. The striker plate 51 is formed to have a long projecting length by being positioned on the outer surface portion of the jib detection lever 45 through the provided through hole 23 and in accordance with the position of the operating piece 30a.
[0022]
The limit switch 30 may need to be replaced with the operating piece 30a that repeatedly contacts the striker plate 51 due to long-term use, but only the operating piece 30a is disposed on the outer surface of the jib detection lever 45 as shown in FIG. By making it exposed to the position, it is possible to easily replace the working piece 30a. At this time, by making the striker plate 51 sufficiently long, contact with the material or the like can be prevented by the striker plate 51, and damage accidents and failures can be prevented.
[0023]
In the above-described embodiment, the support plates 39 and 37 are attached to the post 7 and the tower jib 8 via the horizontal support members 7b and 8b. However, the horizontal support members 7b and 8b are interposed therebetween. Of course, the support plates 39 and 37 may be directly attached to the post 7 and the tower jib 8, and various changes can be made without departing from the scope of the present invention.
[0024]
【The invention's effect】
As described above, according to the tower crane jib fixing device of the present invention, the tower jib connected to the tip end of the post so as to be able to be raised and lowered is fixedly held in a folded state on the post attached to the crane body. In the tower crane jib fixing device, a latch bar is provided on the tower jib so that the tower jib is folded horizontally in a direction intersecting the direction in which the tower jib and the post face each other, and one end projects from the tower jib. The base end portion of the latch plate having a downward notch for engaging with the latch bar is integrally attached to a horizontal support shaft that is rotatably attached to the post side, and is vertically moved together with the support shaft. rotatably is supported to, and on the end side of the latch bar than the latch plate, the supporting base end portions In the vertical jib detection lever mounted pivotably to, and arranged in parallel at a predetermined interval, between the base end of the base end side and the latch plate of the jib detection lever, the jib A spring is interposed so as to urge the front end of the detection lever downward, and a limit switch is provided on the surface of the jib detection lever between the latch plate and the jib detection lever. A striker plate for operating the operating piece of the limit switch when the tip side of the jib detection lever is pushed up by the latch bar engaged with the notch is provided between the latch plate and the jib detection lever. since a structure in which the attachment to the surface of the jib detection lever side of the latch plate, the posts while fixing fold the Tawajibu Etc. When you are allowed to Fushimi, since the limit switch is not exposed to the outside than the jibs detection lever located between the latch plate and the jib detection lever, the Tawajibu incorrectly materials, etc. during transportation are Even if they come into contact, it is possible to prevent the occurrence of an accident or failure of the limit switch, and the limit switch operating piece is inserted through the detection lever to the opposite side of the jib detection lever latch plate. Even if the striker plate is extended to the opposite side of the latch plate of the jib detection lever in accordance with the operating piece of the limit switch, damage to the limit switch and occurrence of failure can be avoided. Exhibits the excellent effect of being able to.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a jib fixing device for a tower crane according to the present invention.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
FIG. 3 is a schematic diagram showing another embodiment of the present invention.
FIG. 4 is a schematic view showing an example of a tower crane.
FIG. 5 is a schematic view showing an example of a conventional jib fixing device.
6 is a BB direction arrow view of FIG.
[Explanation of symbols]
2 Crane body 7 Post 8 Tower jib 30 Limit switch 30a Actuating piece 36 Latch bar 38 Support shaft 40 Latch plate 41 Notch 45 Jib detection lever 48 Tension spring 51 Striker plate

Claims (2)

A tower crane jib fixing device for fixing a tower jib connected to a tip of the post so as to be able to be raised and lowered to a post attached to the crane main body so as to be raised and lowered , wherein the tower jib includes a latch bar and the tower jib. In a state where the tower jib and the post in the folded state are horizontally mounted in a direction intersecting with the facing direction, and one end side protrudes from the tower jib, and is attached to a horizontal support shaft rotatably mounted on the post side. A base end portion of a latch plate having a downward notch for engaging with the latch bar is integrally attached, and is supported so as to be pivotable in the vertical direction together with the support shaft, and the end of the latch bar is more than the latch plate. the part side, a jib detecting lever proximal portion mounted rotatably in the vertical direction to the support shaft, the required spacing Arranged in parallel Te, between the base end of the base end side and the latch plate of the jib detection lever, via a spring so as to urge pivot the distal end side of the jib detection lever downward Otherwise, further, attaching the limit switch on the surface of the latch plate side of the jib detection lever in between the latch plate and the jib detection lever, the latch bar engaged with the notch tip side of the jib detection lever A striker plate for operating the operating piece of the limit switch when pushed up is attached to the surface of the latch plate on the jib detection lever side between the latch plate and the jib detection lever. A tower crane jib fixing device. The limit switch operation piece is positioned on the opposite side of the jib detection lever latch plate through the jib detection lever, and the striker plate is aligned with the limit switch operation piece and the latch plate of the jib detection lever. The tower crane jib fixing device according to claim 1, wherein the tower crane extends to the opposite side.

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