JP2008050068A - Counterweight attachment/detachment device and fitting method for mobile crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a counterweight attachment/detachment device for a mobile crane having excellent efficiency of engagement work when rod tip parts of lifting/lowering cylinders are engaged with a counterweight, reducing the labor burden on workers and preventing damage of a contact part during attachment/detachment operation. <P>SOLUTION: The counterweight attachment/detachment device 50 has the lifting/lowering cylinders 51, engagement step parts 53 and engagement hole parts 60. The engagement step part 53 is an annular body protruded from the rod tip part of the lifting/lowering cylinder 51. The engagement hole part 60 is provided with a pair of guide plates 61 arranged in the forward and backward directions so as to oppose to each other with the counterweight 30 placed on a vehicle body rear part and with lock projection parts 63 provided in the upper part of the guide plates 61 and projecting toward the other opposing guide plate sides. Space parts 62 through which the engagement step parts 53 can pass from both right and left sides with respect to the engagement hole parts 60 by turning of a turning table 10 are formed between the guide plates 61, and opening parts through which the rods 51a can pass are formed between the lock projection parts 63. A fixing device 70 for fixing the counterweight 30 on the turning table 10 when the counterweight 30 is pulled up is provided in the rear part of the turning table 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for attaching / detaching a counterweight to / from the rear part of a swivel of a large mobile crane and a mounting method thereof.

  A mobile crane is generally equipped with a counterweight at the rear of the swivel base in order to increase the lifting capacity. In a small mobile crane, the total weight does not matter, so the counterweight is fixed directly to the swivel with bolts, etc., whereas in a large mobile crane, the counterweight is removed from the swivel and They are transported by vehicles. Then, the transported counterweight is attached to the swivel at the work site.

  As an example of an apparatus for attaching and detaching the counterweight, one described in Non-Patent Document 1 is known, and this prior art will be described with reference to FIG. FIG. 1A shows a plan view of the counterweight, FIG. 1B shows a side view of the rear part of the swivel with the counterweight mounted, and FIG. 1C shows A in FIG. The enlarged view of a part is shown, FIG.1 (d) has shown sectional drawing of the part corresponded to the II arrow of the figure (c). As shown in these drawings, the counterweight attaching / detaching device 80 has wedge portions that are attached to the left and right sides of the rear portion of the swivel base 10 and that form engaging step portions 81a that protrude outward from the rod at the tip portion of the rod. A pair of elevating cylinders 81 and cylinder holes that are disposed on the counterweight 82 and that form a pair of engaging hole portions 83 that can be engaged with the engaging step portions 81a of the pair of elevating cylinders 81 are provided. It becomes. On the inner surface of the upper left portion of the engagement hole 83, a wedge receiver for forming a locking projection 84 protruding inward of the hole is provided. A notch 85 is formed on the upper right side of the engagement hole 83, and the distal end of the elongated rod is moved into the engagement hole 83 so that the locking step 81 a is engaged with the locking projection 84. It is possible to match.

  In order to attach the counterweight 82 to the rear portion of the swivel base 10 by using the counterweight attaching / detaching device 80, the counterweight 82 is placed at a predetermined position on the rear portion of the vehicle body, and the lifting / lowering cylinder 81 has a corresponding engagement hole portion 83. The swivel base 10 is swung so as to be positioned above, the lifting cylinder 81 is extended, and the tip end of the rod is inserted into the engagement hole 83 so that the tip end of the rod moves toward the engagement protrusion. The swivel base 10 is turned to the right to engage the engaging step part 81 a with the engaging protrusion part 84.

  Here, since the engagement protrusion 84 is formed on the inner surface of the upper left portion of the engagement hole 83, the engagement protrusion 64 can be engaged with the engagement step 81a and the engagement protrusion 84. It is necessary to turn the swivel base 10 to the right so that the engagement step portion 81a is positioned on the right side and the engagement step portion 81a moves to the engagement protrusion 64 side. If the swivel base 10 is turned left so that the engagement step portion 81a is positioned on the left side of the engagement hole portion 83 and the engagement step portion 81a approaches the engagement hole portion side, the engagement step portion 81a is It may collide with the cylinder part which forms the engaging hole part 83, and these may be damaged. For this reason, in order to engage the engagement step portion 81a and the engagement projection portion 84, it is necessary to turn the turntable 10 to the right by positioning the engagement step portion 81a on the right side of the engagement hole portion 83. . That is, the turning direction of the swivel base 10 for engaging the engaging step part 81a and the engaging protrusion part 84 is limited to one direction of right turning.

  In this manner, when the engagement step portion 81a and the engagement protrusion 84 are engaged, the turning of the turntable 10 is stopped. Then, the lifting cylinder 81 is reduced and the counterweight 82 is pulled up and attached to the rear part of the swivel base 10. Then, a lock pin is inserted through the engaging step 81a and the engaging hole 83 in the engaged state, and these are fixed.

“LTM1100NV Operation Manual” (Germany), p353-363

  In this conventional counterweight attaching / detaching device, the engaging projection is formed on the left upper inner surface of the engaging hole, and the engaging step is formed in a wedge shape protruding to the outside of the rod at the tip of the rod. In order to engage the engagement step portion with the engagement protrusion, as described above, it is necessary to position the engagement step portion on the right side of the engagement hole portion and to turn the swivel to the right. For this reason, the conventional counterweight attaching / detaching device has a problem that the turning direction of the turntable is limited to one direction.

  In addition, when engaging the engaging step portion with the engaging protrusion, when the swivel base tries to turn right beyond these engaging positions, the inner surface of the cylindrical portion in which the engaging step portion forms the engaging hole portion. Or the engaging protrusion collides with the rod tip, which may cause damage. For this reason, when performing the engagement work, a delicate turning operation of the turntable is required, and there is a problem that this work is troublesome for the operator.

  Further, when engaging the engaging stepped portion and the engaging protrusion, in the above-described engaging method, the swivel is swung so that the lifting cylinder is positioned above the corresponding engaging hole. When the swivel is swung with the cylinder extended in advance, and the tip of the rod moves through the notch formed in the engagement hole into the hole, the lifting cylinder is moved above the engagement hole. The swiveling operation of the swivel for positioning to the position becomes unnecessary, and the engaging operation can be facilitated. In this case, the swivel base is turned to the right in a state in which the lift cylinder disposed on the right turn downstream side of the swivel base of the pair of lift cylinders in plan view is moved to a position other than between the pair of engagement holes. Then, any of the engaging step portions of the pair of lifting cylinders cannot be engaged with the corresponding engaging protrusion. For this reason, the lifting cylinder arranged on the downstream side of the swivel base in the pair of lifting cylinders may be moved in advance to a position between the pair of engagement holes. When the engaging work is performed by moving the swivel, the range in which the swivel can be swung is limited between the pair of engaging holes, and the workability of the engaging work is deteriorated.

  Further, the swiveling position adjusting operation for adjusting the swiveling position of the swivel base so that the lifting cylinder is positioned above the corresponding engagement hole is performed by the center of the alignment bolt in which the marker provided on the swivel base is attached to the swivel bearing. Since it is confirmed by visual confirmation that it has moved until it indicates the position, the workability is poor, and if it is mistakenly confirmed, the engagement step portion collides with the inner surface of the cylindrical portion forming the engagement hole portion, or the engagement projection portion. May collide with the rod tip and damage them.

  In addition, the work of fixing the engaging step formed at the tip of the rod to the engaging hole is performed by inserting the lock pin through these, but this locking work is a manual work by the operator. There is a problem that the burden of the labor of the person is heavy.

  The present invention has been proposed in order to cope with such a problem, and when engaging the rod tip of the elevating cylinder and the counterweight, the workability of the engagement work is good, and the labor load of the operator is increased. It is an object of the present invention to provide a counterweight attaching / detaching device for a mobile crane that can reduce the load and that does not damage the contact portion during the attaching / detaching operation.

  In order to solve such a problem, the present invention has the following features. The present invention includes a vehicle body having a traveling means (for example, the wheel 5 in the embodiment) that can be self-propelled, a swivel that is turnable to the left and right with respect to the vehicle body, and can be raised and lowered on the swivel And a counterweight attaching / detaching device for a mobile crane (for example, the wheel crane 1 in the embodiment) equipped with a boom attached to the rear and a counterweight detachably attached to the rear of the swivel. A pair of elevating cylinders arranged so that the rods are located on the left and right sides and the cylinder tube is located on the upper side; an engagement step provided at the tip of each rod of the pair of elevating cylinders; and a counterweight The counterweight is placed on the rear part of the vehicle body, with a pair of engagement hole portions that can be engaged with the engagement step portions of the pair of lifting cylinders. , The pivoting of the swivel base, characterized in that the passable moving from right and left sides of the engaging step portion with respect to the engagement hole.

  According to this feature, the counterweight attachment / detachment device includes the elevating cylinder, the engagement step portion, and the engagement hole portion, and the engagement step is turned by turning the turntable in a state where the counterweight is placed on the rear portion of the vehicle body. By allowing the counterweight to pass through from the left and right sides with respect to the engagement hole, the swivel can be swung from any swiveling position in either the left or right direction with the counterweight placed on the rear of the vehicle body. In addition, the engagement step portion and the engagement hole portion can be engaged and disengaged. For this reason, the turning direction of the turntable when the engagement step and the engagement protrusion are engaged is not limited, and the turntable can be turned in a desired direction even in a narrow work site. The workability of the attaching / detaching work can be improved.

  Further, the aforementioned engaging step portion is formed in an annular shape so as to protrude radially outward of the rod from the tip end portion of the rod, and the pair of lifting cylinders are arranged at positions having the same predetermined distance from the turning center of the swivel base. The pair of engagement hole portions are arranged at positions having the same predetermined distance from the turning center of the swivel base with the counterweight placed on the rear portion of the vehicle body. A pair of guide plates disposed opposite to each other in the front-rear direction of the vehicle body, and a locking projection provided on the upper portion of each guide plate and projecting to the opposite guide plate side. A space portion is formed between the guide plates so that an engagement step portion that moves by turning of the swivel can pass through, and an upper portion of the space portion is opened between the pair of locking projections to The rod of the lifting cylinder that moves by turning is opened so that it can pass through. Characterized in that the opening is formed.

  According to this feature, the pair of elevating cylinders and the engagement hole provided in the counterweight placed on the rear part of the vehicle body are disposed at positions having the same predetermined distance from the turning center of the swivel base. An engaging step portion that is moved by turning of the swivel base is formed between the guide plates so as to be able to pass through, and the rod of the elevating cylinder can pass between the pair of locking projections by turning of the swivel stand. By forming the opened opening, it is possible to turn the turntable beyond the engagement position between the engagement stepped portion and the locking projection. For this reason, a delicate turning operation of the swivel base in the engagement work between the engagement step part and the locking projection part is not required, so that the workability of the engagement work can be improved and the engagement step part and the engagement step part are engaged. It is possible to eliminate the possibility that the stop protrusions collide and damage them. In addition, since the swivel base can be swung in any direction from the right or left to an arbitrary swivel position, the swivel base is swung with the lifting cylinder extended, and the engagement step portion is brought into the engagement position with the locking projection. It can be moved, the width of the engagement work can be widened, and the workability of the engagement work can be further improved. Further, since the engaging stepped portion and the locking protruding portion are in contact with each other in the direction of movement, there is no problem in the engaged state even if the contact positions are slightly shifted. For this reason, the operation | work which moves a turntable to the position which can engage an engagement step part and a latching protrusion part becomes easy, and the workability | operativity of an engagement operation | work can further be improved.

  Further, according to the present invention, when the counter weight is pulled up to the mounting position of the rear part of the swivel base by the pair of lifting cylinders with the engagement step part and the engagement hole part engaged, the counter weight is fixed to the swivel base. A fixing device is provided.

  According to this feature, it is necessary for the operator to directly fix the counterweight by providing a fixing device for fixing the counterweight to the swivel when the counterweight is pulled up to the mounting position at the rear part of the swivel by the elevating cylinder. This reduces the labor burden on the operator.

  Further, the above-described fixing device can be operated by remote control.

  According to this feature, by enabling the fixing device to be operated by remote operation, an operator working the swivel base and the boom does not need to operate the fixing device away from the driving cabin or the like for performing these operations. The operability of the fixing device can be improved.

  Further, the present invention provides a moving body equipped with a traveling means so as to be able to turn on a self-propelled vehicle body, a boom can be raised and lowered on the turning table, and a counterweight is detachably attached to the rear part of the turning table. A counterweight mounting method for a crane, wherein the counterweight is placed at a predetermined position on the rear part of the vehicle body, and the rods of a pair of lifting cylinders provided at the rear part of the swivel base are extended downward to move the swivel base to the left and right. Rotate in either direction and engage the engagement step provided at the tip of each rod of the pair of lifting cylinders with the corresponding engagement hole of the pair of engagement holes disposed at the top of the counterweight. The swivel is turned to a position where it can be moved, and the swivel of the swivel is locked by a lock pin. The pair of lift cylinders are reduced to engage the engagement step part and the engagement hole, and the counter weight is attached to the rear part of the swivel. Pull up to position And features.

  According to this feature, when the counterweight is mounted on the rear part of the swivel base, the swivel base can be swung in either the left or right direction so that the engagement step part and the engagement hole can be engaged. The swiveling direction of the swivel base is not limited when engaging the engaging projection with the engaging projection, and the swivel base can be swung in a desired direction even in a narrow work site, thereby improving the workability of the counterweight. Can do.

  In addition, the present invention is characterized in that after the above-described counterweight mounting method is performed, the counterweight raised to the mounting position is locked to the swivel base by a fixing device mounted on the rear part of the swivel base.

  According to this feature, when the counterweight is pulled up to the mounting position at the rear part of the swivel base, the fixing device locks the counterweight to the swivel base, so that it is not necessary for the operator to perform this locking work directly. Can reduce the burden on the workers.

  The counterweight attaching / detaching device and mounting method for a mobile crane according to the present invention has the above-described characteristics, and when engaging the rod tip of the lifting cylinder and the counterweight, the workability of the engaging work is good. The labor burden on the operator can be reduced, and the contact portion is not damaged during the attachment / detachment operation.

  Hereinafter, an embodiment of a counterweight attaching / detaching device for a mobile crane according to the present invention will be described with reference to FIGS. In the present embodiment, an all-terrain wheel crane among mobile cranes will be described as an example.

  First, an outline of a wheel crane equipped with the counterweight attaching / detaching device of the present invention will be described. As shown in FIG. 2 (side view) and FIG. 3 (plan view), the wheel crane 1 has a plurality of wheels 5 on the left and right sides of the vehicle body 3 and can be self-propelled. On the other hand, a swivel base 10 that can turn left and right is attached, and an extendable boom 15 is attached to the swivel base 10 so that it can be raised and lowered. Outrigger jacks 20 are attached to the front and rear portions of the vehicle body 3 so as to project from the vehicle body 3 and ground the tip of the jack to stably support the vehicle body 3. A driving cabin 22 for driving the vehicle is provided at the front end of the vehicle body 3, and an operating cabin 25 for operating the rotating platform 10, the boom 15 and a fixing device described later is provided at the left end of the rotating platform 10. . A counterweight attaching / detaching device 50 according to the embodiment of the present invention is installed at the rear part of the turntable 10 in order to attach the counterweight 30 to the turntable 10 in a detachable manner.

  As shown in FIG. 4 (partial sectional view) and FIG. 5 (plan view, side view, sectional view), the counterweight attaching / detaching device 50 is attached to the left and right sides of the rear part of the swivel base 10 and the rod 51a is moved downward. A pair of elevating cylinders 51 positioned so that the cylinder tube 51b is positioned above, an engaging step 53 formed at the tip of each rod 51a of the pair of elevating cylinders 51, and an upper portion of the counterweight 30 And a pair of engaging hole portions 60 that can be engaged with the engaging step portions 53 of the pair of lifting cylinders 51.

  The elevating cylinder 51 is a hydraulic single-acting cylinder that is disposed in a substantially vertical direction with respect to the vehicle body 3, and controls the supply and discharge of a valve (not shown) connected to the rod-side oil chamber to expand and contract the rod 51a. Can be controlled. The engagement step portion 53 formed at the distal end portion of the rod 51a is formed in an annular shape so as to protrude outward in the radial direction of the rod 51a from the distal end portion of the rod 51a. That is, the outer diameter of the engagement step portion 53 is larger than that of the rod 51a. The upper surface of the engagement step portion 53 extends substantially parallel to the vehicle body 3.

  The engagement hole portion 60 is attached to the upper end portion of the support member 32 provided in the weight division body 31 provided in the bottom portion of the counterweight 30. The weight division body 31 includes a flat weight body 33 and the pair of support members 32 that are attached to both ends of the weight body 33 and extend upward. Are provided with a pair of left and right positioning holes 34. The engagement hole portion 60 is provided on a pair of guide plates 61 disposed opposite to each other in the front-rear direction of the vehicle body 3 in a state where the counterweight 30 is positioned and placed on the rear portion of the vehicle body, and is provided on the upper portion of each guide plate 61 to face each other. It has the latching projection part 63 which protrudes to the other guide plate 61 side to do.

  A space portion 62 is formed between the pair of guide plates 61 so that the engaging step portion 53 that moves by turning of the swivel base 10 can be opened from both the left and right sides with respect to the engaging hole portion 60. That is, the space portion 62 has a size including the movement locus of the engagement step portion 53. The left and right sides and the upper part of the space part 62 are opened to allow the engagement step part 53 to pass therethrough.

  Further, between the pair of locking projections 63, the upper portion of the space portion 62 is opened, and the rod 51a of the elevating cylinder 51 that moves by turning the swivel base 10 passes from both the left and right sides with respect to the engagement hole portion 60. An opening 64 is formed in which the engaging step 53 and the locking projection 63 are open so as to be engageable. That is, the opening 64 has a size larger than the movement trajectory of the rod 51 a and smaller than that of the engagement step 53. The opening 64 is open at both the left and right sides and at the top to allow the rod 51a to pass therethrough. The distal end portion of the locking projection 63 is formed in a linear shape, but is not limited to a linear shape as long as the rod 51a can pass therethrough, and may be formed in a curved shape. The height of the pair of locking projections 63 is substantially the same.

  A fixing plate 35 extending in the vertical direction and connected to the weight body 33 is attached to the outer peripheral surface of the support member 32 on the side facing the other support member 32. A locking recess 36 is provided on the upper portion of the fixing plate 35.

  Further, a fixing device 70 for fixing the counterweight 30 pulled up by the counterweight attaching / detaching device 50 to the rear portion of the swivel base is attached to the rear part of the swivel base 10. The fixing device 70 includes a rotating cylinder 71 attached to both side surfaces of the rear part of the swivel base 10 and a fixing arm attached to the rear part of the swivel base 10 below the rotating cylinder 71 so as to be rotatable in the vertical direction. 72 and a roller portion 73 that is rotatably attached to the lower end portion of the fixing arm 72 and can engage with the locking recess 36. The distal end portion of the rotating cylinder 71 is connected to the upper end portion of the fixing arm 72 via the link member 75, and the expansion and contraction of the rotating cylinder 71 is changed to the vertical swing of the fixing arm 72. By the expansion / contraction control of the rotating cylinder 71, the fixing arm 72 can move between a fixed position extending downward in a substantially vertical direction and a storage position extending along the bottom surface of the swivel base 10. Expansion and contraction of the rotation cylinder 71 can be remotely operated by operating an operation switch provided in the operation cabin 25 described above.

  As shown in FIG. 6 (perspective view), the counterweight 30 lifted by the counterweight attachment / detachment device 50 configured as described above is formed by laminating a plurality of weight main bodies 33 on a weight division body 31 in the center portion. The other weight division bodies 38 are configured to be hooked on both sides. In the upper part of the counterweight 30, a guide groove portion 39 is formed in which the above-described engagement step portion 53 of the elevating cylinder 51 can move in a state where the counterweight 30 is placed on the rear portion of the vehicle body.

  Further, as shown in FIG. 7 (plan view), a positioning member 11 extending to the left front side is attached to the front portion of the swivel base 10 to which the counterweight attaching / detaching device 50 is attached. A hole (not shown) through which the lock pin 13 is inserted is formed at the tip of the positioning member 11, and when the lock pin 13 is inserted into the hole and a lock hole (not shown) provided in the vehicle body 3, the engagement described above is performed. The swivel position of the swivel base 10 can be positioned at a position where the step 53 and the engagement hole 60 can be engaged.

  Next, a mounting method for mounting the counterweight 30 to the rear part of the swivel base 10 by using the counterweight attaching / detaching device 50 configured as described above will be described. First, as shown in FIG. 8 (rear view), the counterweight 30 is placed at a predetermined position on the rear portion of the vehicle body 3. At this time, a positioning pin (not shown) provided at the rear portion of the vehicle body is inserted into the positioning hole 34 of the weight division body 31 described above, and the counterweight 30 is positioned at a predetermined position at the rear portion of the vehicle body.

  And each rod 51a of a pair of raising / lowering cylinder 51 is extended below, and the swivel base 10 is rotated in either the left or right direction. That is, the turning direction of the turntable 10 is determined according to the situation at the work site. Thus, since the turning direction of the swivel base 10 may be either left or right, the swivel direction of the swivel base 10 is not limited, and the swivel base 10 can be swung in a desired direction even in a narrow work site. The workability of mounting the counterweight 30 can be improved.

  And as shown in FIG. 4, the engagement step part 53 formed in the front-end | tip part of each rod 51a of a pair of raising / lowering cylinder 51 engages with the corresponding engagement hole part 60 arrange | positioned at the upper part of the counterweight 30. The swivel base 10 is swung so that the engaging step portion 53 is moved into the space portion 62 of the engaging hole portion 60 so as to be able to do so. At this time, since the engagement step portion 53 can pass through the space 62 of the engagement hole portion 60, the engagement hole portion 60 corresponding to one engagement step portion 53 corresponds to the engagement step portion 53. Even if it is located downstream of the other engagement hole 60 in the turning direction, one engagement step 53 passes through the other engagement hole 60 and moves to the corresponding engagement hole 60. be able to. For this reason, in the state which extended the rod 51a of the raising / lowering cylinder 51, the turning angle of the turntable 10 is not restricted. Accordingly, the swivel base 10 can be swung by extending the rod 51a of the elevating cylinder 51 at any swiveling position of the swivel base 10, and the workability of the mounting work can be improved. Further, there is no possibility that the rod 51a collides with the engagement hole 60, and damage to the elevating cylinder 51 and the engagement hole 60 can be prevented.

  And if the engagement step part 53 moves to the position which can be engaged with the engagement hole part 60, turning of the turntable 10 will be stopped. At this time, the engaging portion between the engaging step portion 53 and the locking projection 63 of the engaging hole portion 60 is planarly opposed and has a predetermined width in the moving direction. The engagement step 53 and the engagement hole 60 can be engaged even if they are displaced. For this reason, it is not necessary to make the turning stop position of the turntable 10 strict, and the stopping work can be facilitated.

  Then, as shown in FIGS. 4 and 7, in order to lock the turning of the swivel base 10, the lock pin 13 is inserted into the lock hole provided in the vehicle body 3 via the support member 11 attached to the swivel base 10. . By this turning lock operation of the turntable 10, the turntable 10 can position the turning position of the turntable 10 in a state where the engagement step portion 53 and the engagement hole portion 60 are located at the engageable positions. . Since the turning lock operation is performed at the front portion of the turntable 10 that is distant from the counterweight 30, the operation can be performed without worrying about the counterweight 30.

  Then, the pair of elevating cylinders 51 is reduced to engage the engaging step portion 53 and the engaging hole portion 60, and the elevating cylinder 51 is further reduced to raise the counterweight 30 to the mounting position at the rear portion of the swivel base 10. Then, the fixing cylinder 71 of the fixing device 70 is reduced, and the fixing arm 72 is swung downward and moved to the fixing position. When the fixing arm 72 moves to the fixing position, the roller portion 73 engages with the locking recess 36 and the counterweight 30 is fixed to the rear portion of the swivel base 10. Thus, when the counterweight 30 is pulled up to the mounting position at the rear of the swivel base, the fixing device 70 fixes the counterweight 30 to the swivel base 10, so that it is not necessary for the operator to fix the counterweight 30 directly. , The labor burden on the operator can be reduced.

  In the above-described embodiment, the all terrain crane has been described as an example. However, the rough terrain crane can be similarly equipped with the counterweight attaching / detaching device of the present invention. Moreover, although the wheel 5 is shown as a means for enabling the vehicle body 3 to travel, a crawler may be used.

The counterweight equipped with the conventional mobile crane and this attaching / detaching device are shown. FIG. 5A shows a plan view of the counterweight, and FIG. 4B shows the counterweight attaching / detaching device attached to the rear part of the swivel base. The side view is shown, the figure (c) shows the enlarged view of A part of the figure (a), the figure (d) is the sectional view of the part equivalent to the II arrow of the figure (c). Show. The side view of the wheel crane which mounts the counterweight attachment / detachment device concerning one embodiment of the present invention is shown. The top view of the wheel crane carrying the counterweight attachment / detachment apparatus concerning one embodiment of this invention is shown. Sectional drawing of the counterweight attachment or detachment apparatus concerning one embodiment of this invention is shown. The engagement recessed part which is a part of the counterweight attachment / detachment apparatus concerning one embodiment of this invention is shown, The same figure (a) shows the top view of an engagement recessed part, The same figure (b) is the side surface of an engagement recessed part The figure (c) shows sectional drawing of the part corresponded to the VV arrow of the figure (a). The perspective view of the counterweight with which the rear part of the turntable was mounted | worn is shown. The top view of the turntable which can insert a lock pin in the front part of a turntable is shown. The rear view of the counterweight attachment / detachment apparatus for demonstrating the action | operation of the counterweight attachment / detachment apparatus concerning one embodiment of this invention is shown.

Explanation of symbols

1 Wheel crane (mobile crane)
3 Car body 5 Wheel (traveling means)
DESCRIPTION OF SYMBOLS 10 Rotating stand 15 Boom 30 Counterweight 50 Counterweight attachment / detachment apparatus 51 Lift cylinder 51a Rod 51b Cylinder tube 53 Engagement step part 60 Engagement hole part 61 Guide plate 62 Space part 63 Locking projection part 64 Opening part 70 Fixing device

Claims (6)

A vehicle body having a traveling means and capable of self-propelling, a swivel arranged to turn left and right with respect to the car body, a boom attached to the swivel so as to be raised and lowered, and a rear part of the swivel A counterweight attaching / detaching device for a mobile crane equipped with a counterweight detachably attached,
A pair of elevating cylinders arranged such that the rod is located below and the cylinder tube is located above both the left and right sides of the rear part of the swivel;
An engaging step provided at the tip of each rod of the pair of lifting cylinders;
A pair of engagement hole portions that are arranged at a predetermined interval on the upper part of the counterweight and are engageable with the engagement step portions of the pair of lifting cylinders;
With the counterweight placed on the rear portion of the vehicle body, the engagement step portion can be moved from both the left and right sides with respect to the engagement hole portion by turning the swivel base. Counterweight attachment / detachment device for mobile cranes. The engaging step portion is formed in an annular shape so as to protrude radially outward of the rod from the tip portion of the rod,
The pair of lifting cylinders are disposed at positions having the same predetermined distance from the turning center of the swivel base,
The pair of engagement hole portions are disposed at positions having the same predetermined distance from the turning center of the swivel base in a state where the counterweight is placed on the rear portion of the vehicle body.
The engaging hole portion includes a pair of guide plates disposed opposite to each other in the front-rear direction of the vehicle body in a state where the counterweight is placed on the rear portion of the vehicle body, and another guide plate provided at an upper portion of each guide plate and facing each other. A locking projection that protrudes to the side, and a space portion is formed between the pair of guide plates that is open so that the engagement stepped portion that moves by turning of the swivel can pass therethrough. An opening is formed between the locking protrusions so that the upper portion of the space is opened and the rod of the elevating cylinder that moves by turning of the swivel base is opened so as to pass therethrough. Item 2. A counterweight attaching / detaching device for a mobile crane according to Item 1.   When the counter weight is pulled up to the mounting position of the rear part of the swivel base by the pair of lifting cylinders with the engagement step part and the engagement hole part engaged, the counter weight is fixed to the swivel base. The counterweight attaching / detaching device for a mobile crane according to claim 1, wherein a fixing device is provided.   The counterweight attaching / detaching device for a mobile crane according to claim 3, wherein the fixing device is operable by remote control. A mobile crane counter provided with a traveling means having a swivel base on a self-propelled vehicle body, a boom mounted on the swivel base, and a counterweight detachably attached to the rear part of the swivel base. A weight mounting method,
Place the counterweight at a predetermined position on the rear part of the vehicle body,
Extending each rod of a pair of lifting cylinders provided at the rear of the swivel downward to turn the swivel in either the left or right direction,
Positions at which the engagement step portions provided at the tip portions of the rods of the pair of lift cylinders can be engaged with the corresponding engagement hole portions of the pair of engagement hole portions arranged on the upper portion of the counterweight. Move to
Locking the swivel with the lock pin,
A counterweight for a mobile crane, wherein the pair of elevating cylinders are reduced to engage the engagement step portion and the engagement hole portion to raise the counterweight to a mounting position at the rear portion of the swivel base. Wearing method.   After performing the counterweight mounting method according to claim 5, the counterweight raised to the mounting position is locked to the swivel base by a fixing device mounted on the rear part of the swivel base. How to install counterweight on mobile crane.

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