JPH0641360B2 - Wheel crane - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel crane such as a rough terrain crane. A general construction of a conventional wheel crane is shown in FIG. A is a lower traveling body, B is an upper revolving body mounted on the lower traveling body A, 1 is a revolving frame of the upper revolving body B, and either one of the left and right sides of the revolving frame 1 (usually, On the right side, which will be described below in this example), a cabin 1a is installed which is commonly used as a cockpit for both crane work and traveling. In FIG. 6, 1b is a winch box provided at the rear of the revolving frame 1, W1 and W2 are both main and auxiliary winches provided in the winch box 1b, and R1 and R2 are The main winding rope and the auxiliary winding rope 2 drawn out from the winches W1 and W2 are counterweights attached to the rear surface of the winch box 1b. Further, a boom 3 is mounted on the revolving frame 1 so as to be able to move up and down. In the boom 3, the boom foot 31 at the lower end of the boom base is pivotally attached to the upper part of the revolving frame 1 by a boom foot bin 32, and can be hoisted around the boom foot bin 32 by the boom hoisting cylinder 3a. Has become. Reference numeral 4 is a gantry provided at the base end of the boom 3, and has two gantry sheaves 41 and 42,
The main winding and auxiliary winding ropes R1 and R2 drawn out from the winches W1 and W2 are guided toward the boom tip end by the gantry sheaves 41 and 42. [0007] The wheel crane is
Since it can be used on narrow roads, including urban areas, and can be used in narrow spaces, it is required to have a small vehicle length, vehicle width, and vehicle height, and a lift similar to that of a truck crane. Therefore, in the conventional wheel crane, the hoisting fulcrum of the boom 3 is set as high as possible in order to increase the hoisting height, and the boom 3 is hoisted horizontally during traveling of the crane. It was However, according to this structure, the boom 3 is at the upper part of the left side surface of the cabin 1a during traveling, that is, the eye point P which is the standard viewpoint position of the driver in the cabin 1a.
(For the definition of eye points, see the page 68 of the New Vehicle Examination Standards under the supervision of the Vehicle Examination Division, Land Safety Department, Ministry of Transport, Vehicle Examination Division, Ministry of Transportation, Traffic Safety and Pollution Research Institute, Ministry of Transport.) It was. As a result, the lateral field of view during traveling becomes extremely poor, and there is a problem in traveling safety. Although it is conceivable to arrange the boom above the eye point, this makes the boom higher than the ceiling of the cabin and increases the vehicle height. Also,
If the boom, which occupies about 1/4 of the total weight of the crane, is raised to a high position, the center of gravity of the crane becomes high, and the wheel crane with a small vehicle width cannot secure the standard value of the rollover angle for safety. [0012] The way left there is the actual Kaisho 60-133
No. 889, the boom is pivoted at the lowest possible position (below the eyepoint). However, although this improves the lateral field of view, the boom hoisting fulcrum lowers, resulting in a sacrifice in the lifting height. Since a crane cannot work unless the lifting hook can be hoisted to the working position height, if the lifting height decreases, even if the lifting height is several cm, the load cannot be hung by the difference of several cm. It falls, and the whole crane becomes useless and long. Therefore, this hoisting height is a very important condition for the crane, and it was a strong demand of both the producer and the user to extend even 1 cm. As described above, in the wheel crane, the lift that determines the crane capacity and the traveling field of view for traveling safety are trade-offs. In the technique described in the above publication, the boom is of a middle-bending type in order to secure a high lift. However, because of this, the boom weight increases, the boom structure becomes complicated, and the weight of the front side becomes larger than the weight of the rear side during traveling, resulting in poor axial balance. On the other hand, as another measure, it is conceivable to lengthen the boom to provide it at a lower position, but this increases the amount of overhang of the boom forward when traveling (forward protrusion amount, X in FIG. 5). To do. In this case, (a) the minimum turning radius is increased by the increase of the vehicle length, (b) it becomes difficult to sense the boom tip from the driver's seat, and (c) the forward visibility is deteriorated by the boom. As a result, the ability to enter narrow spaces becomes worse, the driver and pedestrians in the vicinity feel intimidated when driving in an urban area, and a rear-end collision accident easily occurs. The situation becomes difficult to see. In addition, there is an adverse effect such as a delay in coping with the jumping out of the boom side of the child. In the first place, if one is prepared for such an adverse effect, it is technically necessary to achieve the two propositions of high lift and side view, including the provision of the boom above the eye point as described above. It is really easy to achieve, and it is essential to achieve compatibility without such adverse effects. Therefore, the present invention provides a wheel crane capable of achieving both a high lift and a good traveling visibility without causing any adverse effects such as an increase in the amount of boom overhang. According to the present invention, an upper revolving structure is mounted on a lower traveling structure so as to be rotatable about a vertical axis, and a rotating frame of the upper revolving structure is used for crane work and traveling. In a wheel crane equipped with a cabin that is shared as both cockpits and a boom that can be raised and lowered freely,
The upper end of the boom at the base end of the boom in the collapsed state of the boom is projected upward to form this boom as a boom foot. (I) The boom foot is lower than the ceiling of the cabin. At a position higher than the upper surface of the rear end of the traveling body and closer to the center of rotation than the rear end surface of the lower traveling body, it is pivotally attached to the upper end of the revolving frame to serve as a boom undulation fulcrum, and (II) the front end is the base end. In the front lowering position, which is located lower than the above, crosses the side of the cabin below the eye point in the cabin, and (III) in the retracted state when traveling, the tip portion protrudes from the front end of the lower traveling body. In addition, it is arranged so as to end at a position close to the lower traveling body. According to this structure, the boom crosses the side surface of the cabin below the eye point during traveling of the crane, so that the side view can be secured (improvement of the side view). On the other hand, according to the requirement of (III), the overhang amount of the boom during traveling becomes small, so that the minimum turning radius becomes small and the feeling of the boom tip from the driver's seat becomes easy to grasp, and the front view is also improved. To be done. As a result, the ability to enter narrow spaces is improved. Also,
Even in urban areas, drivers and pedestrians in the surrounding area will not be intimidated, it will be easy to see the course of the road when turning, and it will be possible to quickly deal with children jumping out from the boom side. In addition, by tilting the boom in a forward-downwardly inclined posture during traveling, the undulation fulcrum can be raised and the boom length can be increased even if the overhang amount is small as described above. That is, the lifting height can be increased. In this case, since the boom base end is projected upward to form the boom foot, the boom hoisting fulcrum can be further raised while the boom is kept at a low position, and the hoisting range can be further increased. Further, according to the requirement of (I), the boom does not increase the vehicle height and the rear end turning radius can be reduced. Therefore, workability in a narrow space is further improved. On the other hand, the combination of the boom tilting downward in the maximum laid-down state and the swivel function enables various works that were impossible with conventional cranes. Embodiments of the present invention will be described with reference to FIGS. C is a lower traveling body, D is an upper swing body, 5 is a swing frame, and 6 is a boom. In this wheel crane, the upper end portion of the boom 6 at the base end portion of the boom 6 in the collapsed state of the boom is projected upward to form this protruding portion as a boom foot 61. The boom foot 61 is located above the ceiling of the cabin 5a. Is also at a lower position, and is above the upper surface of the engine box 10 provided at the rear end portion of the lower traveling body C (the rear end upper surface of the lower traveling body C) and at the rear end of the engine box (the lower traveling body C). A boom foot pin 62 pivotally attaches to the rear end and the upper end of the revolving frame 5 at a position closer to the center of revolving than the rear end). By setting the boom hoisting fulcrum as described above, the vehicle height is not increased by the boom 6 (above requirement), and the rear end turning radius can be reduced (above requirement). Of the above, the engine box 1
Due to the requirement of a position above 0, the engine box 10 can be provided at a position closer to the turning center,
The vehicle length can be reduced. The boom 6 is in a retracted state, at a position lower than the eye point P in the cabin 5a, and
With the portion facing the lower traveling body C positioned above the upper surface of the lower traveling body C, the boom tip end may be lower than the boom base end so as to traverse one side surface of the cabin 5a in a downwardly inclined posture. It is attached to the swivel frame 5. In other words, the vertical position of the boom hoisting fulcrum, the stroke of the boom hoisting cylinder 6a, etc. are set so as to obtain such a maximum laid state. By doing so, it is possible to secure a left-side field of view during traveling. On the other hand, if the height of the boom tip is the same as in the case where the boom 6 is laid down horizontally below the eyepoint P, the height of the boom base should be increased. You can However, in this case, if the boom hoisting fulcrum is set too high, the position of the boom 6 itself also becomes high, so that it is not preferable in terms of the lateral field of view even within the condition below the eye point P. Therefore, in the present crane, as a measure against this point, the boom base end is projected upward and this protruding portion is used as the boom foot 61. Therefore, the boom undulating fulcrum should be raised without raising the position of the boom 6 itself. You can That is, compared with the case where the base end of the boom itself is pivotally attached to the revolving frame as a boom foot without providing such a protruding portion, if the height position of the boom itself is the same, the boom hoisting fulcrum is Can be further increased to further increase the lifting height. Further, the boom 6 is arranged in a state in which the boom 6 is in a contracted and laid-down state during traveling, in which a tip portion thereof projects further forward than a front end of the lower traveling body C and ends at a position close to the lower traveling body C. There is. As a result, the amount of overhang X of the boom 6 during traveling is reduced, the minimum radius of rotation is reduced, the sense of the boom tip from the driver's seat is easily grasped, and the forward visibility is also improved. For this reason, it is easy to enter narrow spaces, does not give a sense of intimidation to the surrounding drivers and pedestrians even in urban areas, and it is easy to check the course condition on the boom side when turning around, and it is also quick for children to jump out from the boom side. It is possible to drive safely as if it were a large passenger car. The wheel crane is designed so that the approach angle (hill-entry angle) θ is a certain angle or more, and the boom overhang amount X is also set so that the tip of the boom does not greatly enter the approach angle θ. Is set. In this case, in this wheel crane, since the boom 6 is tilted forward and downward during traveling, the boom 6
The height of the boom tip is lower than that in the case where the boom is tilted horizontally, and the boom overhang amount X is naturally reduced due to the relationship with the approach angle θ. That is, the boom tip portion comes close to the lower traveling body C. On the other hand, by tilting the boom 6 downward (upward), it is possible to raise the height position of the undulating fulcrum of the boom 6. As described above, the boom length can be increased even if the overhang amount X is small. With these two points, it is possible to increase the lifting height during crane work while reducing the overhang amount X of the boom 6. In the figure, reference numeral 7 is a winch box in which both main winding and auxiliary winding winches W1 and W2 are housed. The winch box 7 is installed on the upper surface of the boom 6 (the upper surface when the boom is lying down). ing. 63 is both winches W
1, both main winding and auxiliary winding ropes R1, drawn from W2
It is a rope hook that lowers R2 below the eyepoint P and guides it toward the boom tip. On the other hand, the boom rest 8 is provided on the front upper surface of the lower traveling structure C, and the boom side mounting bracket 64 of the boom hoisting cylinder 6a is fixed in the left and right direction by the boom rest 8 during traveling of the crane. Supported. As a result, the boom 6 is pivotally locked during traveling. Further, 9 is a counterweight provided at the rear end of the revolving frame 5. By the way, the wheel crane, that is,
In the crane where the upper structure (upper revolving structure) revolves including the boom, and lifting work is performed by this revolving function,
When the boom 6 is laid down in a non-conventional state in which the boom 6 is tilted forward and downward, the following unique effect (operation effect due to a combination of the turning function and the tip-down tilt of the boom 6) is achieved. (I) As shown in FIG. 5, when performing indoor installation work on the first floor of a building where the crane cannot enter, after the crane is laid horizontally in front of the entrance and after turning to the entrance side, The boom 6 will be extended and inserted indoors. In this case, when the height h of the entrance is low, and when the height of the entrance is low and the actual indoor height is low due to the obstacles such as the beams F, the conventional crane in which the boom can only be laid down horizontally , It was impossible to work because the boom could not be inserted indoors. On the other hand, in the present crane, after the boom 6 is turned, it is extended in the maximum fall state of the tip so that the boom 6 can be indoors without hitting any obstacles such as the upper entrance or the ceiling beam F. You can plug it in and work freely with the swivel function. (2) Since the wheel crane has a turning function, a turning lock is required during traveling. When the swing lock is performed by the boom rest 8 as in this embodiment, if the boom 6 is horizontal, the following problems occur. In the wheel crane, a rotary joint J is attached to the center of the slewing bearing G as shown in FIG. 1 in order to exchange electric signals and pressure oil between the lower traveling structure C and the upper rotating structure D.
Is provided. The rotary joint J has a relatively large vertical dimension, and is usually arranged so as to project above the upper surface of the lower traveling body C. Therefore, even if the boom 6 is installed at a low position, it is limited to above the rotary joint J. Moreover, since the boom hoisting cylinder 6a is located above the rotary joint J, the position of the boom 6 is further above. Therefore, when the boom rest 8 is pivotally locked as in this embodiment, when the traveling posture of the boom 6 is horizontal, the distance between the boom 6 and the upper surface of the lower traveling body C becomes relatively large. The required height of the boom rest 8 (protruding dimension from the upper surface of the lower traveling body) also becomes high, and there arises a problem that the boom rest becomes an obstacle when various work is performed on the lower traveling body C during crane work. . On the other hand, in the case of the present crane in which the boom 6 is inclined forward and downward, the boom tip 8 can be brought close to the upper surface of the lower traveling body C, so that the boom rest 8 can be low. (3) As a working example of the wheel crane,
There is a case where it is desired to move an object at a low position on the ground without dragging it in the air while keeping it in the grounded state by dragging it using only the turning function. During such work, it is desirable to apply the turning force to the object as a horizontal moving force in a straight line. To that end, it is desirable to minimize the distance between the boom tip and the object (we want to hoist the suspension hook close to the limit and shorten the sling rope). In this case, according to this crane in which the maximum fall angle of the boom is smaller than 0 °, the distance between the boom tip and the object can be minimized (this distance becomes smaller as the boom 6 is extended). Can fully meet various work demands. As described above, according to the present invention, since the boom crosses the side surface of the cabin below the eye point during traveling of the crane, a side view can be secured. Further, since the overhang amount of the boom during traveling becomes small, the minimum turning radius becomes small, and it becomes easy to grasp the feeling of the boom tip from the driver's seat. For this reason, the narrow space penetration is improved. Also,
Even in urban areas, drivers and pedestrians in the surrounding area will not be intimidated, it will be easy to see the course of the road when turning, and it will be possible to quickly deal with children jumping out from the boom side. In addition, by tilting the boom in a downward-sloping posture during traveling, the undulation fulcrum can be raised and the boom length can be increased even if the overhang amount is small as described above. That is, the lifting height can be increased. In particular, in the present invention, the boom base end portion is projected upward, and this protruding portion is used as the boom foot, so that the boom can be raised and lowered while keeping the boom in a low position (while maintaining a good lateral view). The fulcrum can be further raised to further increase the lifting height. Further, the undulating fulcrum of the boom is lower than the ceiling of the cabin, higher than the upper surface of the rear end of the lower traveling body, and closer to the center of rotation than the rear end surface of the lower traveling body. Since the vehicle height is not increased by the boom, the turning radius of the rear end can be reduced and the workability in a narrow space can be improved. Further, the combination of the boom tilting forward and downward in the retracted state and the turning function enables various works that were impossible in the past, and the work capacity of the wheel crane can be expanded.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a wheel crane according to an embodiment of the present invention. FIG. 2 is a plan view of the same. FIG. 3 is an enlarged cross-sectional view taken along the line EE of FIG. FIG. 4 is a partially enlarged view of FIG. FIG. 5 is a front view showing an example of work by the crane. FIG. 6 is a side view showing a conventional wheel crane. [Explanation of reference signs] C Lower traveling body D Upper revolving superstructure 5 Revolving frame 5a Cabin P Cabin eyepoint 6 Boom 61 Boom foot 62 formed by projecting the upper end of the boom base end upward. fulcrum)

Claims (1)

[Claims] 1. An upper revolving structure is mounted on the lower traveling structure so that it can rotate around the vertical axis.The revolving frame of this upper revolving structure has a cabin that is used as a cockpit for both crane work and traveling, and a boom that can be raised and lowered. In the wheel crane provided with, the upper end portion of the boom at the base end portion of the boom in the collapsed state of the boom is projected upward to form the protruding portion as a boom foot, and the boom is (I) the boom foot is the cabin Is lower than the ceiling of the lower traveling body, is higher than the upper surface of the rear end portion of the lower traveling body, and is closer to the center of swing than the rear end surface of the lower traveling body, and is pivotally attached to the upper end portion of the revolving frame to serve as a boom elevating fulcrum. ) With the tip part located below the base end part in the front descent state, cross the side of the cabin below the eye point in the cabin, and run (III). In a contracted collapsed state when, mobile crane, wherein a distal end portion is arranged to terminate at a position close to protrude from the front end of the undercarriage and the undercarriage.