JP3658116B2 - Jib overhang storage mechanism of self-propelled crane - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a jib overhanging storage mechanism for storing a jib for supplementing the length of a boom mounted on a crane vehicle or the like along the longitudinal direction of the boom and for extending the jib from the stored state to the tip of the boom. .
[0002]
[Prior art]
In general, a self-propelled crane is provided with a jib that projects from the tip of an extendable boom to compensate for the length of the boom.
Such a jib is normally stored along the length of the boom when not in use, with its proximal end directed toward the boom distal end and its distal end directed toward the boom proximal end. ing. And the jib stored in this way is conventionally projected over the tip of the boom by various means. An example is shown in FIGS. 10 and 11.
[0003]
FIG. 10 shows a conventional example in which a jib 105 stored on one side of the boom 100 is projected to the tip of the boom 100 only by a crane lifting rope 104. That is, first, in a state where the base end portion of the jib 105 stored on one side surface of the boom 100 is rotatably locked to the locking portion 109 of the boom head 103, the crane lifting rope 104 is connected to the boom 100 side. The guide sheave 101 and the rooster sheave 102, the guide sheave 106 on the jib 105 side, and the guide sheave 107 on the base end portion of the boom 100, and the tip of the rope 104 are hooked on the rope hooking portion 108 of the jib 105. . In this state, the rope 104 is once wound up and tensioned, and then the rope 104 is unwound while passing over the boom 100, so that the jib 105 is locked by its own weight as shown in FIG. Rotate with the portion 109) as a fulcrum and hang from the tip of the boom 100. Next, after removing the rope 104 from the guide sheave 107 at the base end portion of the boom 100, the rope 104 is wound up so that the jib 105 is projected forward of the boom 100.
[0004]
FIG. 11 shows that a truss-like jib 105 stored on one side of the boom 100 is extended to the tip of the boom 100 by a jib overhanging storage mechanism detachably attached to the boom head 103 and a crane lifting rope 104. A conventional example is shown.
[0005]
In this case, the jib overhanging storage mechanism is detachably attached to the boom head 103 via the rotation coupling device 112, and overhangs at the end of the boom 100 and on the side of the boom 100 rotated 180 degrees from this position. It consists of a jib mounting frame 111 that can be rotated laterally (side of the boom 100) with a reversing position along, and a hydraulic cylinder 113 that is mounted on the frame 111. The jib 105 is rotatably attached to the frame body 111 whose lower end on the base end side is in the inverted position in the state shown in FIG. The upper part on the base end side is connected to the telescopic rod 115 of the hydraulic cylinder 113. Further, in this state, the crane lifting rope 104 is attached to a hook 110 whose tip can be brought into contact with the jib 105 after being hung around a sheave provided on each of the boom 100 and the jib 105.
[0006]
When the jib 105 is projected from the tip of the boom 100 from the state shown in FIG. 11A, the rod 115 of the hydraulic cylinder 113 is first extended with the boom 100 raised at an appropriate angle. As a result, the jib 105 rotates downward about the support shaft 114 to be in the state shown in FIG. In this state, this time, the rope 104 is wound up. Accordingly, the frame body 111 is rotated by the tension of the rope 104 via the rotation coupling device 112 and is inverted to the front of the boom 100. At this time, the jib 105 is also reversed together with the frame body 111. Then, from this state, when the rod 115 of the hydraulic cylinder 113 is contracted, the jib 105 pivots upward about the support shaft 114 and protrudes from the tip of the boom 100.
[0007]
[Problems to be solved by the invention]
However, as shown in FIG. 10, in the method of projecting the jib 105 to the tip of the boom 100 using only the crane lifting rope 104, it is necessary to hang the rope 104 around a large number of sheaves. The overhanging work of 105 becomes very complicated, and the jib 105 cannot be easily and quickly overhanged.
[0008]
These disadvantages are slightly eliminated by the method of FIG. 11 using the jib overhanging storage mechanism. However, the thing of FIG. 11 does not change that the jib 105 is extended by the winding operation of the rope 104 after all, and two different operations such as the operation of the hydraulic cylinder 113 and the winding operation of the rope 104 are performed. Therefore, it is difficult to say that the jib 105 can be easily and quickly extended. In addition, attaching the jib overhanging storage mechanism to the boom 100 increases the weight of the boom 100. As a result, the lifting ability is reduced, and the falling moment of the vehicle body is increased, thereby improving the stability of the vehicle body. There is also the problem of getting worse.
[0009]
The present invention is made by paying attention to the above circumstances, and its purpose is to easily and quickly project the jib to the tip of the boom without impairing the lifting ability or the stability of the vehicle body, It is another object of the present invention to provide a jib overhanging storage mechanism that can store a jib on the side of a boom easily and quickly.
[0010]
[Means for Solving the Problems]
In order to solve the problem, the present invention moves a jib that compensates for the length of the boom between a position protruding forward of the boom and a retracted position along one side surface of the boom. In the jib overhang storage mechanism of a self-propelled crane that overhangs and retracts,
A support portion capable of rotatably supporting one end of the jib, forming a distal end portion of the boom, and rotatably supported with respect to a proximal end portion of the boom, the distal end being the distal end of the boom A boom head movable at a projecting position toward the side and a retracted position toward the base end side portion of the boom;
A first drive cylinder device for moving the boom head to an extended position and a retracted position;
A second drive cylinder device for rotating the jib rotatably supported by the support portion of the boom head around the support portion;
Comprising
In a state where one end of the jib is supported by the support portion of the boom head, the boom head is rotated by the first driving cylinder device, and the jib is rotated by the second driving cylinder device. A self-propelled crane characterized in that the jib is moved between a retracted position along one side of the boom and a position projecting forward of the boom by rotating around a support portion. Jib overhang storage mechanism.
In addition, the present invention extends and stores the jib by moving a jib that compensates for the length of the boom between a position protruding forward of the boom and a storage position along one side of the boom. In the jib overhang storage mechanism of a self-propelled crane,
A first support portion that can rotatably support one end of the jib, and a second support portion that can rotatably support one end of a tension rod that applies a projecting tension to the jib, Formed at the front end of the boom, supported pivotably with respect to the base end side portion of the boom, at a position where the front end projects toward the front end side of the boom and a storage position toward the base end side of the boom A movable boom head;
A first drive cylinder device for moving the boom head to an extended position and a retracted position;
A second cylinder device attached to the other end of the jib and having a telescopic rod connected to the other end of the tension rod;
Comprising
One end of the jib and one end of the tension rod are supported by the first support portion and the second support portion of the boom head, respectively, and the jib is attached to the boom by the first cylinder device. The boom head is moved between a retracted position along a side surface and a forward projecting position of the boom, and the jib and the tension rod are moved by expanding and contracting the telescopic rod of the second cylinder device. The jib and the tension rod are moved between a retracted position along one side surface of the boom and a position projecting forward of the boom by rotating about the first support portion and the second support portion. A self-propelled crane jib overhanging storage mechanism characterized in that
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a wheel crane (rough terrain crane) 1. The wheel crane 1 is provided with a dual-purpose cab (hereinafter referred to as a cab) 14 that can be used for both crane work and traveling operation, and travels with the boom 18 tilted down to the lower side of the cab 14. Can do. As a result, a sufficient lateral field of view during traveling can be secured, and the center of gravity of the vehicle body can be lowered, so that the stability of the vehicle body during traveling can be improved.
[0012]
The wheel crane 1 includes a carrier 10 as a traveling vehicle body, and a turntable 12 is placed on the carrier 10. On the swivel base 12, a swivel body 16 including a cab 14 and a telescopic boom 18 is rotatably mounted. In this case, the telescopic boom 18 is formed by connecting a plurality of booms so as to be telescopic, and can be extended by an unillustrated telescopic cylinder, and is stretched between the revolving body 16 and the lower surface of the base end side boom 18a. The hoisting cylinder 19 is adapted to move up and down.
[0013]
Outriggers 26 are attached to both the front and rear sides of the carrier 10. These outriggers 26 are attached to the lower end of the jack portion 26a by extending the beam to the side of the carrier 10 during crane work and extending the jack portion 26a of the cylinder / piston structure attached to the tip of the beam. A grounding plate is pressed against the ground to support the carrier 10.
[0014]
Further, the revolving body 16 is provided with a winch (not shown), and the wire 22 is wound or fed out by the winch. The wire 22 fed out from the winch was hooked to the first sheave 32 on the upper side attached to the boom head 25 located at the tip of the boom 18 (the most advanced boom 18b located at the most tip side in the extended state). Thereafter, the rope is wound around the second sheave 33 on the lower side, which is also attached to the boom head 25, and the sheave of a hook block (not shown) having a load hanging hook, so that the load hanging hook is started from the tip of the boom 18. Can be hung up and down freely. In the state shown in FIG. 1, the boom head 25 is rotated by a boom head storage mechanism, which will be described later, to a state where the tip is directed to the base end side of the boom 18 and stored in the side of the boom 18. ing.
[0015]
Further, a sheave bracket 15 having an auxiliary sheave 34 is preferably provided at the tip of the boom head 25 so as to protrude and retract. Therefore, especially during lightly loaded crane work, it is possible to carry out a single rope crane work with a high lifting speed by hanging a separate single rope wire hung on the first sheave 32 of the boom head 25 over the auxiliary sheave 34. It becomes.
[0016]
Further, a jib 60 for compensating for the length of the telescopic boom 18 is stored on the side surface of the base end side boom 18a. The jib 60 includes a pair of leg portions 61 and 61 connected by a plurality of connecting portions, and the leg portions 61 and 61 extend in a bifurcated manner toward the base end side of the jib 60. That is, the jib 60 is tapered from the proximal end side toward the distal end side, and has a generally flat V shape (ladder shape) as a whole. The jib 60 extends along the side surface of the boom 18 (18a) in a state where the base end side is directed to the distal end side of the boom 18 and the leg portions 61 and 61 are horizontally positioned with respect to each other. Stored in a fixed state.
[0017]
In addition, a hydraulic cylinder 99 is mounted on the tip side of the jib 60 to constitute a jib overhanging storage mechanism together with the boom head 25 so as to extend and store the jib 60. The hydraulic cylinder 99 is attached to the jib 60 so that the rod 99a extends toward the base end side of the jib 60, and one end of a tension rod 70 that holds the protruding state of the jib 60 is attached to the tip of the rod 99a. It is connected. In the state shown in FIG. 1, the tension rod 70 is stored in a fixed state on the side surface of the boom 18 so as to extend along the jib 60.
[0018]
The sheave shafts 33a and 33a of the second sheave 33 protrude from both sides of the boom head 25, and the jib 60 is a concave engagement formed at the distal ends of the leg portions 61 and 61 (base ends of the jib 60). The joints 62 and 62 are projected from the tip of the boom 18 with the sheave shafts 33a and 33a engaged (see FIG. 2). In the state shown in FIG. 1, the jib 60 is moved from the retracted position along the side surface of the boom 18 to the tip side of the boom 18, and the engaging portions 62 and 62 are engaged with the sheave shafts 33 a and 33 a. Is shown in the state.
[0019]
As shown in FIGS. 2 to 4, the boom head 25 is attached to the most advanced boom 18 b so as to be rotatable about a rotation shaft 35. Specifically, the rotation shaft 35 is fixed to the side end portion of the tip member 49 provided at the tip of the most advanced boom 18b in a state inclined toward the front of the boom 18, and the boom head 25 is attached to the pivot head 35. When the pivot head 35 is pivoted about the pivot shaft 35 so that the distal end is directed to the proximal end side of the boom 18 and positioned on the side of the boom 18, the distal end of the boom head 25 is obliquely above the longitudinal axis direction of the boom 18 In order to be directed to the right (so as to be in the state of FIG. 1), a predetermined angle θ is made with respect to a straight line Z perpendicular to the longitudinal axis direction of the boom 18. And the connection part 25a provided in the one side edge part of the base end of the boom head 25 is attached with respect to this rotation axis | shaft 35 so that rotation is possible.
[0020]
In order to rotate the boom head 25 about the rotation shaft 35, a hydraulic cylinder 65 is disposed inside the most advanced boom 18b. The hydraulic cylinder 65 rotates the boom head 25 about the rotation shaft 35 by operating a link mechanism 68 connected to the boom head 25.
[0021]
As specifically shown in FIG. 3 as viewed in the direction of arrows AA in FIG. 2, a bracket 90 is provided at the base end of the boom head 25 inside the connecting portion 25a. The bracket 90 and the hydraulic cylinder 65 is connected by a link mechanism 68. Specifically, the link mechanism 68 includes a long rectangular first link 68a, one end of which is pivotally connected to the bracket 90 of the boom head 25 via a pivot shaft 91, and a first link 68a. The second link 68b is connected to the other end of the second link 68b through a swivel shaft 92 so as to be pivotable. The other end of the second link 68b is a support that supports the hydraulic cylinder 65. It is connected to 69 via a turning shaft 93 so as to be able to turn. Further, the rod portion of the hydraulic cylinder 65 is connected to the middle portion of the second link 68b via the pivot shaft 94. In this case, the pivot shafts 92, 93, 94 are located in the vicinity of each vertex of the triangle of the second link 68b.
[0022]
Therefore, according to such a boom head storage mechanism including the rotation shaft 35, the hydraulic cylinder 65, and the link mechanism 68, when the hydraulic cylinder 65 is extended from the state of FIG. The boom head 25 is pushed forward via the pivot, and the boom head 25 rotates about the rotation shaft 35. In a state where the rod portion of the hydraulic cylinder 65 is extended by a predetermined amount, the link mechanism 68 is completely deployed, and the boom head 25 is in a state in which the distal end thereof is directed to the proximal end side of the boom 18 and the length of the boom 18 is increased. It is stored in the side of the boom 18 in a state of being directed obliquely upward with respect to the axial direction (a state indicated by a solid line in FIGS. 1 and 4).
[0023]
Further, when the rod portion of the hydraulic cylinder 65 is contracted from the retracted state and the boom head 25 is pulled toward the tip end side of the boom 18 via the link mechanism 68, the boom head 25 rotates around the rotation shaft 35. Thus, the boom head 25 is positioned at the tip of the most advanced boom 18b (the state of the two-dot chain line in FIGS. 2, 3 and 4). In this state, when the fixing pin 51 is inserted into, for example, the fixing hole 53 provided at the other end of the boom head 25 and the corresponding hole of the tip member 49, the boom head 25 protrudes to the tip of the most advanced boom 18b. Fixed in state. In this case, it is desirable to automatically insert the fixing pin 51 into the fixing hole 53 by using, for example, a hydraulic cylinder. In FIG. 4, the hydraulic cylinder 65 and the link mechanism 68 are not drawn for simplicity.
[0024]
In addition, when the boom head 25 is pivoted about the pivot shaft 35 inclined forward of the boom 18 in this way, the boom head 25 is in a state where the boom head 25 projects over the tip of the most advanced boom 18b. The tip is oriented obliquely downward with respect to the longitudinal axis direction of the boom 18. Therefore, the jib 60 also has a longitudinal direction of the boom 18 when the engaging portions 62, 62 are engaged with and attached to the sheave shafts 33a, 33a of the second sheave 33, as shown by a one-dot chain line in FIG. It is directed obliquely downward with respect to the axial direction. Accordingly, the tension rod 70 that connects the tip of the jib 60 (in this embodiment, the rod 99a of the hydraulic cylinder 99 provided at the tip of the jib 60) and the tip of the boom head 25 to apply the projecting tension to the jib 60, Depending on the length, it is impossible to connect to the portion of the boom head 25 located in the vicinity of the first sheave 32 as in the prior art.
[0025]
Therefore, in this embodiment, a separate fixing link body 75 is provided so as to be able to project and retract on the boom head 25, and the other end of the tension rod 70 can be fixed to the fixing link body 75. That is, the fixing link body 75 includes three link portions 75a, 75b, and 75c, and one end of the first link portion 75a is pivotably attached to a portion of the boom head 25 located in the vicinity of the second sheave 33. ing. The other end of the first link portion 75a is provided with a first fixing portion 82 to which the other end of the tension rod 70 is detachably fixed. At the other end of the first link portion 75 a, an extension portion 59 extending laterally therefrom is formed, and the extension portion 59 is connected to one end of the second link portion 75 b via a turning shaft 83. Are pivotally connected. Further, the other end of the second link portion 75b is connected to a portion near one end of the third link portion 75c via a turning shaft 85 so as to be turnable. Moreover, the 2nd fixing | fixed part 84 fixed to the support body 55 fixed to the boom head 25 is provided in the end of the 3rd link part 75c. The other end of the third link portion 75c is connected to the sheave shaft 86 of the first sheave 32 so as to be pivotable.
[0026]
The second fixing portion 84 is formed as, for example, a pin insertion hole. By inserting the fixing pin 58 into this pin insertion hole and, for example, the insertion hole of the support body 55, the fixing link body 75 is The contracted and retracted state indicated by the dotted line is maintained. Further, when the fixing link body 75 in the contracted and retracted state indicated by the two-dot chain line in the figure is manually pulled forward, for example, the fixing link body 75 is stretched so as to form a triangle as indicated by the solid line in the figure. Is issued. In this overhanging state, the first fixing portion 82 for fixing the tension rod provided at the end of the first link portion 75a protrudes forward of the boom head 25 as a triangular apex. Therefore, in this state, even when the jib 60 is oriented obliquely downward with respect to the longitudinal axis direction of the boom 18 as indicated by a one-dot chain line in the drawing, one end of the jib 60 is the tip of the jib 60 (in this embodiment, the jib 60 The other end of the tension rod 70 fixed to the rod 99a) of the hydraulic cylinder 99 provided at the front end of the hydraulic cylinder 99 can be fixed to the first fixing portion 82.
[0027]
Next, a method for projecting and storing the jib 60 by the jib projecting storage mechanism including the pivotable boom head 25 and the hydraulic cylinder 99 will be described.
As shown in FIG. 1, when the jib 60 stored along one side surface of the boom 18 is projected to the distal end of the boom 18, first, it is inverted and stored with the distal end facing the proximal end side of the boom 18. The engaging portion 62 of the leg portion 61 of the jib 60 is engaged with the sheave shaft 33a of the boom head 25, and the other end of the tension rod 70 whose one end is connected to the rod 99a of the hydraulic cylinder 99 is stretched in a triangular state. It fixes to the 1st fixing | fixed part 82 of the taken out link body 75 for fixation. In this state, as shown by a solid line in FIG. 5, the boom 18 is lifted by a predetermined angle, and the front end boom 18 b is extended by a predetermined length, whereby the jib 60 is moved to the front end side of the boom 18. To move away from the fixing part 97 of the boom 18.
[0028]
From this state (the state indicated by the solid line in FIG. 5), when the rod 99a of the hydraulic cylinder 99 is extended, the jib 60 rotates downward with the sheave shaft 33a as a fulcrum, and the tension rod 70 also rotates downward together with the jib 60 with the fixed portion 82 as a fulcrum. When the rod 99a of the hydraulic cylinder 99 is extended by a predetermined amount, the jib 60 and the tension rod 70 are suspended from the tip of the boom 18 as shown by a two-dot chain line in FIG.
[0029]
Further, when the rod portion of the hydraulic cylinder 65 (see FIG. 2) is contracted in this state (a) and the boom head 25 is pulled toward the tip end side of the boom 18 via the link mechanism 68, the rotating shaft 35 is moved. The boom head 25 is inverted 180 degrees in the center, the boom head 25 is positioned in front of the most advanced boom 18b, and the tension rod 70 and the jib 60 are also inverted together with the boom head 25 to be in the (b) state. At this time, the fixing pin 51 is inserted into the fixing hole 53 provided at the other end of the boom head 25 and the corresponding hole of the tip member 49 (see FIG. 4), and the boom head 25 is moved to the most advanced boom 18b. Secure it overhanging the tip of the.
[0030]
Next, in this state (B), when the rod 99a of the hydraulic cylinder 99 is contracted by a predetermined amount, the jib 60 and the tension rod 70 rise upward and project to the front of the boom 18 as shown in FIG. Fixed in state.
[0031]
When the jib 60 together with the tension rod 70 is retracted along the one side surface of the boom 18 from the state in which the boom 18 is projected forward, the operation opposite to that described above may be performed. In this retracted state, as shown in FIG. 1, the boom head 25 is stored in an upwardly inclined state on the side of the boom 18, and the jib 60 attached to the boom head 25 is also in an upwardly inclined state on the side of the boom 18. Located at.
[0032]
As described above, according to the jib overhanging storage mechanism of the present embodiment, the jib 60 can be boomed only by remotely operating the hydraulic cylinders 65 and 99 sequentially without using a crane lifting wire rope. It can be moved between the retracted position along the 18 side surface and the extended position of the tip of the boom 60. That is, since the jib 60 can be automatically moved between the extended position and the retracted position without performing complicated work of manually wrapping the wire rope, it is easy and quick to extend and retract the jib 60. Can be done.
[0033]
Further, since the jib overhanging storage mechanism of the present embodiment is configured to overhang and store the jib 60 by rotating the boom head 25, the frame body 111 as in the conventional example shown in FIG. It becomes unnecessary. That is, there are few additional members required for overhanging and storing the jib 60, and as a result, there is no possibility that the lifting ability decreases and the vehicle body overturning moment increases with the increase in the weight of the boom 100.
[0034]
Further, in the jib overhanging storage mechanism of the present embodiment, the jib 60 is rotated to the side of the boom 18 by rotating the jib 60 to the side of the boom 18 in order to rotate and store the jib 60 under the boom 18. Compared to the method of overhanging and storing, the space for overhanging storage of the jib 60 can be reduced.
[0035]
Further, according to the present embodiment, the boom head 25 is rotated around the rotation shaft 35 with respect to the boom 18 from the state shown in FIG. 6A, as shown in FIG. Can be stored in the side of the boom 18. Therefore, the total length of the crane vehicle can be shortened from L (see FIG. 6 (a)) to L ′ (see FIG. 6 (b)). As a result, the boom head 25 moves forward when the crane vehicle moves. The danger of colliding with a traveling vehicle or an obstacle can be avoided, or a crane vehicle can pass smoothly at a corner of a narrow road.
[0036]
In this embodiment, since the pivot shaft 35 of the boom head 25 is inclined toward the front of the boom 18 as described above, the boom head 25 is inclined upward as shown in FIG. In this state, it can be stored on the side of the boom 18. As a result, the boom head 25 can be stored without greatly projecting to the lower side of the boom 18, and as a result, the approach angle (a straight line connecting the lower edge of the boom head 25 and the grounding portion of the front wheel becomes the ground). The angle can be increased from α (see FIG. 6A) to α ′ (see FIG. 6B).
[0037]
Thus, the fact that the boom head 25 can be stored in an upwardly inclined state without greatly projecting to the lower side of the boom 18, in particular, is a crane that travels with the boom 18 in a lying position above the cab 14 as shown in FIG. 7. Useful in cars. That is, in the crane vehicle as shown in FIG. 7, when the boom head 25 is changed from the protruding state shown in FIG. 7A to the retracted state shown in FIG. Safety during driving is ensured without being blocked. If the boom head 25 is rotated about an axis substantially perpendicular to the longitudinal direction of the boom 18, the protrusion amount of the boom head 25 to the lower side of the boom 18 does not change. The view from the cab 14 may be blocked by the boom head 25. On the other hand, in the present embodiment, the boom head 25 can be stored in a state where the boom head 25 is tilted upward by the tilt shaft 35, and the amount of protrusion of the boom head 25 to the lower side of the boom can be reduced or eliminated. Good visibility from can be secured.
[0038]
In this embodiment, since the hydraulic cylinder 65 for rotating the boom head 25 is disposed in the inner space of the most advanced boom 18b located on the innermost side of the telescopic boom 18, it is caused by collision with an obstacle. Damage to the hydraulic cylinder 65 can be prevented. Further, since it is not necessary to secure a mounting space for the hydraulic cylinder 65 outside the boom 18, the space can be used effectively and the degree of freedom in design is improved.
[0039]
Further, in the present embodiment, since the link body 75 for fixing the tension rod is provided in the boom head 25 so as to be able to project and retract, the disadvantage caused by providing the rotating shaft 35 in an inclined manner, that is, depending on the length thereof. Can eliminate the inconvenience that the tension rod 70 cannot be attached to the boom head 25. In the case of this embodiment, the link body 75 forms a triangle in its overhanging state, which is very advantageous in terms of strength. In the present embodiment, the link body 75 is manually extended, but this may be automatically performed using a hydraulic cylinder or the like.
[0040]
In the above-described embodiment, the boom head 25 only pivots about the pivot shaft 35. However, as shown in FIG. 8, the boom head 25 can be further raised and lowered. May be.
[0041]
That is, in FIG. 8, a hydraulic cylinder 88 that raises and lowers the boom head 25 is provided on the boom 18 side. Also in this case, the boom head 25 can be reversed around the rotation shaft 35 as in the above-described embodiment (see the two-dot chain line in the figure), but the mechanism is shown in FIG. 8 for simplicity. It has not been.
[0042]
Thus, if the boom head 25 is raised and lowered in the vertical direction, as shown in FIG. 9, the lift can be increased by the amount indicated by H in the drawing, and the working radius is also increased by the amount indicated by L in the drawing. Can do.
[0043]
In this configuration, since a heavy load is applied to the hydraulic cylinder 88, it is desirable that the hydraulic cylinder 88 be a push cylinder rather than a pulling cylinder.
Further, in the conventional example shown in FIG. 11, the same effect as that of the above-described embodiment can be obtained by removing the jib mounting frame 111 and attaching the hydraulic cylinder 113 and the jib 105 to the boom head 25 of the present invention. Can play. In this case, the hydraulic cylinder 113 performs the same function as the hydraulic cylinder 99.
[0044]
Further, in the embodiment described above, the hydraulic cylinder 99 is provided on the upper side of the jib 60, but may be provided on the lower side of the jib 60. In this case, the jib 60 rotates downward about the sheave shaft 33a by contracting the hydraulic cylinder 99 from the extended state.
[0045]
【The invention's effect】
As described above, according to the jib overhanging storage mechanism of the present invention, the jib can be easily and quickly extended to the tip of the boom without impairing the lifting ability and the stability of the vehicle body. It can be easily and quickly stored on the side of the boom.
[Brief description of the drawings]
FIG. 1 is an overall view of a wheel crane provided with a jib overhanging storage mechanism according to an embodiment of the present invention.
2 is an enlarged view of a main part of a boom head storage mechanism constituting the jib overhanging storage mechanism of FIG. 1; FIG.
FIG. 3 is a view taken in the direction of arrows AA in FIG. 2;
FIG. 4 is a plan view of a boom tip portion where a boom head is located.
FIG. 5 is an operation explanatory diagram of the jib overhanging storage mechanism of FIG. 1;
6 is an explanatory diagram for explaining the operation of the boom head retracting mechanism of FIG. 2, wherein (a) shows a state in which the boom head is positioned at the tip of the boom by the boom head retracting mechanism provided on the wheel crane. The figure which shows, (b) is a figure which shows the state which stored the boom head to the side of the boom by the boom head storing mechanism from the state of (a).
7 is an explanatory diagram for explaining the operation of the boom head retracting mechanism of FIG. 2; FIG. 7 (a) is an illustration of a boom head retracting mechanism provided on a crane vehicle that travels with the boom lying down above the cab. The figure which shows the state which located the boom head at the front-end | tip of a boom, (b) is a figure which shows the state which stored the boom head to the side of the boom by the boom head storing mechanism from the state of (a).
FIG. 8 is a diagram schematically showing a mechanism for raising and lowering a boom head up and down.
FIG. 9 is a diagram for explaining the effect obtained by the mechanism of FIG. 8;
FIG. 10 is a diagram showing a first conventional example of a jib overhanging operation.
FIG. 11 is a diagram showing a second conventional example of a jib overhanging operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wheel crane 18 (18a, 18b) ... Boom 25 ... Boom head 33a ... Sheave shaft (1st support part)
35 ... Rotating shaft 60 ... Jib 65 ... Hydraulic cylinder (reversing means)
68 ... Link mechanism (reversing means)
70 ... tension rod 75 ... link body (second support part)
99 ... Hydraulic cylinder (cylinder device)

Claims (2)

A jib for a self-propelled crane that extends and retracts the jib by moving a jib that compensates for the length of the boom between a position where the boom extends forward and a retracted position along one side of the boom. In the overhang storage mechanism,
A support portion capable of rotatably supporting one end of the jib, forming a distal end portion of the boom, and rotatably supported with respect to a proximal end portion of the boom, the distal end being the distal end of the boom A boom head movable at a projecting position toward the side and a retracted position toward the base end side of the boom;
A first drive cylinder device for moving the boom head to an extended position and a retracted position;
A second drive cylinder device for rotating the jib rotatably supported by the support portion of the boom head around the support portion;
Comprising
In a state where one end of the jib is supported by the support portion of the boom head, the boom head is rotated by the first driving cylinder device, and the jib is rotated by the second driving cylinder device. A self-propelled crane characterized in that the jib is moved between a retracted position along one side of the boom and a position projecting forward of the boom by rotating around a support portion. Jib overhang storage mechanism. A jib for a self-propelled crane that extends and retracts the jib by moving a jib that compensates for the length of the boom between a position where the boom extends forward and a retracted position along one side of the boom. In the overhang storage mechanism,
A first support portion that can rotatably support one end of the jib, and a second support portion that can rotatably support one end of a tension rod that applies a projecting tension to the jib, Formed at the front end of the boom, supported pivotably with respect to the base end side portion of the boom, at a position where the front end projects toward the front end side of the boom and a storage position toward the base end side of the boom A movable boom head;
A first drive cylinder device for moving the boom head to an extended position and a retracted position;
A second cylinder device attached to the other end of the jib and having a telescopic rod connected to the other end of the tension rod;
Comprising
One end of the jib and one end of the tension rod are supported by the first support portion and the second support portion of the boom head, respectively, and the jib is attached to the boom by the first cylinder device. The boom head is moved between a retracted position along a side surface and a forward projecting position of the boom, and the jib and the tension rod are moved by expanding and contracting the telescopic rod of the second cylinder device. The jib and the tension rod are moved between a retracted position along one side surface of the boom and a position projecting forward of the boom by rotating about the first support portion and the second support portion. A jib overhanging storage mechanism for a self-propelled crane, characterized in that

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