JP2012035980A - Counterweight attaching/detaching device for mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a counterweight attaching/detaching device for a mobile crane capable of easily attaching and detaching a counterweight to/from the rear part of a revolving frame while making the revolving frame revolvable in a state of supporting the counterweight on even a vehicle with a small longitudinal dimension.SOLUTION: The counterweight attaching/detaching device for the mobile crane includes a counterweight moving mechanism 32 for moving the counterweight W supported on a frame 31 in vertical and longitudinal directions, and a counterweight locking means 33 for locking the counterweight W to the rear part of a bracket 21a of the revolving frame 21 by moving the counterweight W by the counterweight moving mechanism 32. The counterweight W supported on the frame 31 is thereby moved backward to make the revolving frame 21 revolvable, and the counterweight supported on the frame 31 is moved forward and downward to lock the counterweight W to the rear part of the revolving frame 31.

Description

  The present invention relates to a counterweight attaching / detaching device for a mobile crane in which a counterweight can be attached to and detached from a rear part of a swivel base.

  The mobile crane has a swivel that is turnable on the upper surface of a self-propelled vehicle, and a telescopic boom that can be raised and lowered provided on the upper surface of the swivel. This mobile crane is configured so that a counterweight can be detachably attached to the rear part of the swivel base in order to ensure stability when a load is lifted at the tip of the telescopic boom.

  Conventionally, as a counterweight attachment / detachment device for attaching / detaching a counterweight to / from the rear part of a swivel base, a support base for supporting the counterweight is provided on the upper surface of a self-propelled vehicle, and by turning the swivel base, There is known one that engages and disengages the swivel base and the counterweight supported by the support base (for example, cited reference 1).

  In the counterweight attaching / detaching device, the support base must be arranged at a position where the counterweight supported by the support base and the swiveling base that makes the turn do not contact each other. For this reason, a support base cannot be installed in the position which the counterweight supported by the support stand and the turning base which turns turn on the upper surface of a vehicle with the small dimension of the front-back direction.

  In addition, the mobile crane has a height dimension limitation in order to enable traveling on public roads. For this reason, when configuring the counterweight attaching / detaching device, it is required that the height dimension of the mobile crane does not exceed a predetermined height dimension.

  Therefore, even for a vehicle having a small size in the front-rear direction, the counterweight supported on the upper surface of the vehicle (the sub winch fixed to the upper surface of the counterweight) and the swiveling platform do not come into contact with each other. First to third conventional examples shown in FIGS. 10 to 15 are conceivable as counterweight attachment / detachment devices in which the height of the crane does not exceed a predetermined height.

  A counterweight attaching / detaching device 100 of the first conventional example shown in FIGS. 10 and 11 includes a pair of weight supporting members 102 provided in the width direction so as to extend rearward from the rear portion of the swivel base 101, and the rear of each weight supporting member 102. And a cylinder 103 which is provided at the end and can be vertically expanded and contracted. The pair of weight support members 102 are respectively provided at height positions lower than the height dimension of the sub winch W1 fixed to the central portion in the width direction of the upper surface of the counterweight W. Further, the pair of weight support members 102 are respectively provided on the outer side in the width direction of the sub winch W1, and one end portion is located behind the sub winch W1 and the other end portion is located in front of the sub winch W1. ing. The other weight support member 102 is formed in such a length that it can pass through the inside of the sub winch W1 when the swivel base 101 turns. In this counterweight attaching / detaching device 100, the counterweight W is attached to the rear portion of the swivel base 101 by connecting the lower end of the cylinder 103 to the counterweight W supported by the support base 104 and contracting the cylinder 103. The counterweight attaching / detaching device 100 can turn the swivel base 101 only in the direction in which one weight support member 102 is separated from the counterweight W in a state where the counterweight W is supported by the support base 104 on the upper surface of the vehicle body. It is.

  The counterweight attaching / detaching device 110 of the second conventional example shown in FIGS. 12 and 13 extends rearward from the rear portion of the swivel base 111 and has a central portion in the front-rear direction so that the rear end portion can move in the vertical direction. A pair of weight support members 112 in the width direction supported on the swivel 111 so that the front side is rotatable, and a cylinder connected to the front end side of each weight support member 112 to vertically move the rear end portion of each weight support member 112 113. In the counterweight attaching / detaching device 110, a counterweight W is detachably connected to a rear end portion of the weight supporting member 112. In the counterweight attaching / detaching device 110, the counterweight W is attached to the swivel base 111 when the counterweight W and the rear end portion of the weight support member 112 are connected to contract the cylinder 113. When the counterweight W and the weight support member 112 are disconnected and the rear end portion of the weight support member 112 is moved upward, the counterweight attaching / detaching device 110 does not contact the sub winch W1. It can turn.

  Further, the counterweight attaching / detaching device 120 of the third conventional example shown in FIGS. 14 and 15 includes a pair of weight supporting members 122 provided in the width direction so as to extend rearward from the rear portion of the swivel base 121, and each weight supporting member 122. And a cylinder 123 rotatably provided at the rear end portion. In the counterweight attaching / detaching device 120, the weight support member 122 is provided at a position higher than the height of the sub winch W1 on the upper surface of the counterweight W in a state where the counterweight W is supported on the support base 124 on the upper surface of the vehicle. . Further, the cylinder 123 can be held with the central axis directed in the front-rear direction. In this counterweight attaching / detaching device 120, when the cylinder 123 is contracted after the cylinder 123 is connected to the counterweight W supported by the support base 124, the counterweight W is attached to the swivel base 121. When the counterweight W and the cylinder 123 are disconnected and the cylinder 123 is rotated so that the central axis is directed in the front-rear direction, the counterweight attaching / detaching device 120 rotates without contacting the sub-winch W1. It becomes possible.

Japanese Patent Laid-Open No. 11-255481

  In the counterweight attaching / detaching apparatus 100 of the first conventional example, when the counterweight W is supported on the support base 104, the swivel base 101 can be turned only in one direction, and there is a problem that the operability is poor. .

  In the second and third counterweight attaching / detaching devices 110 and 120, in a state where the counterweight W is supported by the support bases 114 and 124, the cylinder 113 is operated to turn the turntables 111 and 121. In addition, there is a problem that workability is poor because work for rotating the cylinder 123 occurs.

  The present invention makes it possible to turn a swivel base with a counterweight supported on the vehicle even in a vehicle having a small size in the front-rear direction, and to easily attach and detach the counterweight to the rear part of the turntable. An object of the present invention is to provide a counterweight attaching / detaching device for a crane.

  According to a first aspect of the present invention, there is provided a mobile crane comprising: a swivel provided so as to be turnable with respect to a vehicle; and a telescopic boom provided so as to be freely raised and lowered with respect to the turntable. A counterweight attaching / detaching device for attaching / detaching a counterweight to the rear of the swivel base, provided on the vehicle, supports the counterweight, and moves the counterweight in the vertical direction and the front-rear direction, and The counterweight is engaged with the rear part of the swivel base by moving the counterweight downward by the counterweight support mechanism and moving toward the swivel base side, and the state in which the counterweight is engaged with the rear part of the swivel base By moving the counterweight upward and moving toward the opposite side of the swivel base, Counterweight engagement means engaging the serial swivel base rear and said counterweight is released, characterized by comprising a.

  According to a second aspect of the present invention, in the counterweight attachment / detachment device according to the first aspect, the counterweight support mechanism includes a gantry that supports the counterweight from below, and the gantry moves downward. A link mechanism that is moved simultaneously to the swivel base and simultaneously moved to the opposite side to the swivel, and a cylinder that operates the link mechanism.

  According to a third aspect of the present invention, in the counterweight attachment / detachment device according to the second aspect, the link mechanisms are respectively provided on the front and rear sides of the left and right sides of the gantry, and the vehicle, the gantry, And a second link member that connects the first link members arranged at the front and the rear to operate the first link members arranged at the front and the rear at the same time. To do.

  According to a fourth aspect of the present invention, in the counterweight attaching / detaching device according to any one of the first to third aspects, the counterweight engaging means extends in the left-right direction provided at the rear part of the swivel base. It has a coupling pin and an engagement hook provided on a side surface of the counterweight and detachably engaged with the engagement pin from above.

  According to a fifth aspect of the present invention, in the counterweight attaching / detaching device according to the fourth aspect, the counterweight attaching / detaching device is provided between the rear portion of the swivel base and a side surface of the counterweight, and is engaged with the engaging pin. Connection fixing means for connecting and fixing the swivel base and the counterweight with the hook engaged is provided.

  According to a sixth aspect of the present invention, in the counterweight attachment / detachment device according to any one of the second to fifth aspects, the counterweight is engaged with the upper surface of the gantry so that the counterweight is engaged with the gantry. And an engaging portion capable of positioning the counterweight.

  According to the first aspect of the present invention, the swivel can be turned by moving the counterweight backward, and the counterweight is locked to the rear part of the turntable by moving the counterweight forward and downward. Can do. Therefore, even if the vehicle has a small size in the front-rear direction, the swivel can be turned with the counterweight supported on the vehicle, and the counterweight can be easily attached to and detached from the rear part of the swivel. Become.

  According to the invention described in claim 2, since the counterweight supported by the gantry can be moved in the vertical direction and the front-rear direction without requiring a plurality of power sources, the manufacturing cost can be reduced. Is possible.

  According to the invention described in claim 3, since the link mechanism is configured with a simple configuration including two types of members, it is possible to reduce the manufacturing cost.

  According to the fourth aspect of the present invention, the counterweight can be locked to the rear part of the swivel base by moving the counterweight from above toward the rear part of the swivel base, and the work for attaching and detaching the counterweight is easy. It becomes.

  According to the fifth aspect of the present invention, since the work for connecting and fixing the swivel base and the counterweight can be performed from the side surface side of the counterweight, it is not necessary to perform the operation on the counterweight, thereby improving safety. It becomes possible to make it.

  According to the sixth aspect of the present invention, since the counterweight can be reliably positioned with respect to the gantry by engaging the engaging portion with the counterweight, the work of installing the counterweight on the gantry is facilitated. Can be done.

It is a side view of the mobile crane which shows one Embodiment of this invention. It is a principal part side view of the mobile crane which shows one Embodiment of this invention. It is a principal part top view of the mobile crane which shows one Embodiment of this invention. It is a perspective view of a gantry and a counterweight movement mechanism which shows one embodiment of the present invention. It is a figure which shows the procedure which attaches a counterweight to the turntable rear part of one Embodiment of this invention. It is a figure which shows the procedure which attaches a counterweight to the turntable rear part of one Embodiment of this invention. It is a figure which shows the procedure which attaches a counterweight to the turntable rear part of one Embodiment of this invention. It is a figure which shows the procedure which attaches a counterweight to the turntable rear part of one Embodiment of this invention. It is a side view of the mobile crane which shows the state which has arrange | positioned the mount frame and the counterweight in the front side of the vehicle. It is a side view of the swivel base rear part and counterweight of the first conventional example. It is a top view of the swivel base rear part and counterweight of the first conventional example. It is a side view of a swivel stand rear part and a counterweight of the second conventional example. It is a side view of a swivel stand rear part and a counterweight of the second conventional example. It is a side view of the swivel base rear part and counterweight of the third conventional example. It is a side view of the swivel base rear part and counterweight of the third conventional example.

  1 to 8 show an embodiment of the present invention.

  The mobile crane 1 provided with the counterweight attaching / detaching device of the present invention includes a traveling vehicle 10 and a crane device 20.

  The vehicle 10 has a pair of left and right wheels 11 at each of a front part and a rear part, and travels using the engine E as a power source. Further, on both the left and right sides of the front side and the rear side of the vehicle 10, there are provided outriggers 12 for preventing the vehicle 10 from overturning during crane work and for stably supporting the vehicle 10. The outrigger 12 is used by extending downward by a jack cylinder (not shown) and grounding the lower end.

  The crane device 20 includes a swivel base 21 that is turnable in the horizontal direction at the center in the front-rear direction of the vehicle 10, a boom 22 that is provided so as to be able to rise and fall with respect to the swivel base 21, and is extendable. And a cabin 23 provided on the swivel base 21.

  The swivel base 21 is provided so as to be turnable with respect to the vehicle 10 by a ball bearing type or roller bearing type turning circle (not shown), and is configured to turn by driving a turning hydraulic motor (not shown).

  The boom 22 is composed of a plurality of boom members, and is configured in a multistage manner in which a boom member adjacent to the distal end side can be accommodated inside the boom member. A hydraulic cylinder (not shown) is provided in the boom member (base boom) 22a on the most proximal end side, and the boom 22 is expanded and contracted by expansion and contraction of the hydraulic cylinder. Further, the most proximal end boom member 22 a has a proximal end portion connected to the bracket 21 a of the swivel base 21 so as to be rotatable in the vertical direction. A hydraulic cylinder 24 for raising and lowering is connected between the distal end side of the central portion in the extending direction of the boom member 22 a and the swivel base 21, and the boom 22 is raised and lowered by the expansion and contraction of the hydraulic cylinder 24.

  The cabin 23 is provided on the side of the bracket 21a on the turntable 21, and an operation related to traveling of the vehicle 10 and an operation related to the crane device 20 are performed.

  In addition, the mobile crane 1 is detachably mounted with a counterweight W at the rear part of the swivel base 21 in order to ensure stability when a load is suspended from the tip of the boom 22. The mobile crane 1 includes a counterweight attaching / detaching device 30 for performing an operation of attaching the counterweight W to the rear portion of the swivel base 21.

  The counterweight attachment / detachment device 30 includes a gantry 31 for supporting the counterweight W from below, a counterweight moving mechanism 32 for moving the gantry 31 supporting the counterweight W in the vertical direction and the front-rear direction, and the counterweight movement. Counter weight locking means 33 for locking the counterweight W to the rear portion of the bracket 21a of the swivel base 21 by moving the counterweight W by the mechanism 32 is provided.

  The gantry 31 includes a pair of support members 31a in the width direction extending in the front-rear direction, and a connecting member 31b that extends in the width direction and connects the front side and the rear side of the pair of support members 31a. It is formed in a shape. On the upper surface of the support member 31a, a protrusion 31c for positioning the counterweight on the gantry 31 is provided. When the protrusion 31 c is fitted into a recess 31 d provided on the lower surface of the counterweight W, the counterweight W is positioned on the gantry 31.

  The counterweight moving mechanism 32 is disposed in the front-rear direction with four struts 32a extending upward from the rear portion of the upper surface of the vehicle 10, a first link member 32b rotatably connected to the upper end side of each strut 32a in the front-rear direction. The first link members 32b are connected to each other, and the first link members 32b arranged in the front and rear are rotatable at the same time, and the first link members 32b arranged in the front and rear are rotated. And a pair of cylinders 32d in the width direction for applying the force to be applied.

  The 1st link member 32b consists of an L-shaped member formed so that a center part may make a right angle, and the center part is connected with the support | pillar 32a. One end of the first link member 32b is rotatably connected to the gantry 31, and the other end is rotatably connected to the second link member 32c. The first link member 32b keeps the top surface of the gantry 31 horizontal and moves the gantry 31 back and forth and up and down.

  The 2nd link member 32c consists of a member extended in the front-back direction, the 1st link member 32b located in the front side is connected with the front end, and the 1st link member 32b located in the back side is connected with the rear end.

  The cylinder 32d has an end on the cylinder tube 32e side connected to the lower end side of the rear column 32a, and a piston rod 32f connected to the other end of the front first link member 32b and the front end of the second link member 32c. Yes. The cylinder 32d moves the mount 31 forward and downward by pulling the cylinder rod 32f into the cylinder tube 32e. The cylinder 32d moves the gantry 31 rearward and upward by pushing the cylinder rod 32f out of the cylinder tube 32e.

  The counterweight locking means 33 is provided on the left and right sides of the extending portion 21b extending rearward from the bracket 21a and on the front surface of the counterweight W, and is detachably engaged with the locking pin 33a. An engaging hook 33b that can be engaged, and a connecting and fixing means 33c for connecting and fixing the swivel base 21 and the counterweight W are provided.

  The locking pin 33a is provided so as to extend outward in the width direction from the left and right side surfaces of the extending portion 21b, and is provided on the upper side and the lower side of the extending portion 21b, respectively.

  The engagement hook 33b is formed in a hook shape whose tip extends downward so as to engage with each locking pin 33a from above.

  The coupling fixing means 33c is an engagement hook 33b engaged with the locking pin 33a by inserting the fixing pin 33f into the pin insertion holes 33d and 33e provided on the extending portion 21b side and the counterweight W side, respectively. Is prevented from coming off. The pin insertion holes 33d and 33e are provided at positions where the holes 33d and 33e communicate with each other with the engagement hook 33b engaged with the locking pin 33a.

  A procedure for attaching the counterweight W to the rear part of the swivel base 21 in the counterweight attaching / detaching device for the mobile crane configured as described above will be described.

  First, as shown in FIG. 5, the gantry 31 that is positioned downward and forward is moved upward and backward by extending the cylinder 32 d.

  Next, as shown in FIG. 6, the counterweight W is lifted using the crane device 20 and placed on the gantry 31. At this time, the counterweight W is positioned by fitting the protrusion 31 c on the top surface of the gantry 31 with the recess 31 d provided on the bottom surface of the counterweight W.

  After the counterweight W is placed on the pedestal 31, as shown in FIG. 7, the slewing base 21 is turned so that the rear portion of the slewing base 21 is positioned in front of the counterweight W, and the cylinder 32d is contracted to reduce the cradle 31. Move downward and forward. When the gantry 31 on which the counterweight W is placed is moved downward and forward, the engagement hook 33b of the counterweight W is engaged with the locking pin 33a provided on the extending portion 21b from obliquely above. As a result, the counterweight W is locked to the rear part of the swivel base 21.

  Finally, as shown in FIG. 8, the mounting work of the counterweight W is completed by inserting the fixing pin 33f into the holes 33d and 33e. At this time, since the connecting and fixing means 33c is provided between the rear portion of the swivel base 21 and the front surface of the counterweight W, the attaching and detaching work of the fixing pin 33f does not need to go up on the counterweight W.

  When the counterweight W attached to the rear part of the swivel base 21 is removed, the counterweight W is moved above the base 31 positioned downward and forward, and the fixing pin 33f is removed from the holes 33d and 33e. After that, the cylinder 32d is extended. Accordingly, the counterweight W is supported from below by the gantry 31 that moves upward and backward, the engagement between the locking pin 33a and the engagement hook 33b is released, and the counterweight W is removed from the rear portion of the swivel base 21.

  As described above, according to the counterweight attaching / detaching device of the mobile crane of this embodiment, the counterweight moving mechanism 32 for moving the counterweight W supported by the gantry 31 in the vertical direction and the front-back direction, and the counterweight movement Counter weight locking means 33 for locking the counter weight W to the rear portion of the bracket 21a of the swivel base 21 by moving the counter weight W by the mechanism 32 is provided. As a result, the swivel base 21 can be turned by moving the counterweight W supported by the gantry 31 backward, and the rear part of the swivel base 31 can be moved by moving the counterweight W supported by the gantry 31 forward and downward. The counterweight W can be locked. Therefore, even if the vehicle 10 has a small size in the front-rear direction, the swivel base 21 can be turned while the counterweight W is supported on the vehicle 10, and the counterweight W can be easily attached to and detached from the rear part of the turntable 21. Can be performed.

  In addition, the counterweight moving mechanism 32 that moves the counterweight W supported by the gantry 31 in the vertical direction and the front-rear direction is operated, the link mechanism including the first link member 32b and the second link member 32c, and the link mechanism are operated. It comprises a cylinder 32d. As a result, the counterweight W supported by the gantry 31 can be moved in the vertical direction and the front-rear direction without requiring a plurality of power sources, so that the manufacturing cost can be reduced.

  In addition, link mechanisms are provided on the front and rear sides of the left and right sides of the gantry 31, respectively, and a first link member 32b that couples the vehicle 10 and the gantry 31 and a first link member 32b that is arranged at the front and rear are coupled to each other. The first link member 32b disposed at the front and rear of the second link member 32c operates simultaneously. Thereby, since the link mechanism is configured with a simple configuration including two types of members, it is possible to reduce the manufacturing cost.

  Further, a latch pin 33a provided on the left and right sides of the extending portion 21b extending rearward from the bracket 21a is provided on the front surface of the counterweight W, and can be detachably engaged with the latch pin 33a. The counterweight W is attached to the rear portion of the swivel base 21 by engaging the mating hook 33b. Thereby, the counterweight W can be locked to the rear part of the swivel base 21 by moving the counterweight W from above toward the rear part of the swivel base 21, and the work of attaching and detaching the counterweight W becomes easy.

  Further, a connection fixing means 33 c for connecting and fixing the swivel base 21 and the counterweight W is provided between the rear part of the swivel base 21 and the counterweight W. Thereby, it is not necessary to perform the work of connecting and fixing the swivel base 21 and the counterweight W on the counterweight W, and the safety can be improved.

  Further, on the upper surface of the gantry 31, a protrusion 31 c is provided that can position the counterweight W with respect to the gantry 31 by engaging with a recess 31 d provided on the bottom surface of the counterweight W. Thereby, the counterweight W can be reliably positioned with respect to the gantry 31 by engaging the recess 31d and the protrusion 31c, and the work of installing the counterweight W on the gantry 31 can be easily performed. It becomes.

In the above-described embodiment, the gantry 31 and the counterweight moving mechanism 32 are provided at the rear of the vehicle 10 of the rough terrain crane, which is the mobile crane 1 having a small longitudinal dimension. In the case of the mobile crane 1 according to the embodiment, the engine E as a power source is disposed at the rear of the vehicle 10, and therefore the rear side dimension in the rear side of the front side dimension of the swivel 21 of the vehicle 10. Is formed large. Therefore, in the case of the mobile crane 1 of the embodiment, the gantry 31 and the counterweight moving mechanism 32 can be disposed above the engine E at the rear of the vehicle 10. However, if the gantry 31 and the counterweight moving mechanism 32 are arranged on the front side of the vehicle 10, the gantry 31 and the counterweight moving mechanism 32 are positioned in front of the front end of the vehicle 10, as indicated by a two-dot chain line in FIG. Resulting in. For this reason, the gantry 31 and the counterweight moving mechanism 32 cannot be arranged on the front side of the vehicle 10 without changing the longitudinal dimension.
However, for example, in the case of a mobile crane having a large front-rear dimension on the front side of the upper surface of the vehicle 10, the gantry 31 and the counterweight moving mechanism 32 may be provided on the front side of the upper surface of the vehicle 10.

  In the above-described embodiment, the counterweight moving mechanism 32 is configured by one mechanism that moves in the front-rear direction and the up-down direction by expansion and contraction of the cylinder 32d. However, the present invention is not limited to this. For example, a mechanism for moving the gantry 31 in the front-rear direction and a mechanism for moving the gantry 31 in the vertical direction may be configured separately.

  In addition, the counterweight W is attached to the rear portion of the swivel base 21 by engaging a locking pin 33a provided at the rear part of the swivel base 21 with an engagement hook 33b provided on the counterweight W. The thing is shown, but it is not limited to this. For example, even if a hook formed in a bowl shape whose end extends upward is provided at the rear part of the swivel base 21, and a pin that can be engaged with the hook is provided on the counterweight, The counterweight W can be locked to the rear part of the swivel base 21.

  In the embodiment, the counterweight W is positioned with respect to the gantry 31 by fitting the projection 31 c provided on the upper surface of the gantry 31 into the recess 31 d provided on the lower surface of the counterweight W. However, the present invention is not limited to this. For example, a protrusion provided on the lower surface of the counterweight W may be fitted into a recess provided on the upper surface of the gantry 31, or the entire lower surface of the counterweight W may be fitted on the upper surface of the gantry 31. You may make it form the recessed part to carry out.

  In the above-described embodiment, the cylinder 32d of the counterweight moving mechanism 32 is connected together with the other end of the first link member 32b on the front side and the front end of the second link member 32c. It is not a thing. In order to operate the first link member 32b and the second link member 32c, the second link member 32c may be connected together with the other end of the first link member 32b on the rear side and the rear end of the second link member 32c. You may make it connect only to 32c.

DESCRIPTION OF SYMBOLS 1 Mobile crane 10 Vehicle 20 Crane apparatus 30 Counterweight attachment / detachment apparatus 31 Base 31c Projection part 32 Counterweight movement mechanism 32b First link member 32c Second link member 32d Cylinder 33 Counterweight locking means 33a Locking pin 33b Engagement hook 33c Connection fixing means W Counterweight

Claims (6)

A counterweight that attaches and detaches a counterweight to the rear part of the swivel base of a mobile crane that includes a swivel base that can be swiveled with respect to a vehicle, and a telescopic boom that can be raised and lowered relative to the swivel base. A detachable device,
A counterweight support mechanism provided in the vehicle for supporting the counterweight and for moving the counterweight in the vertical direction and the front-rear direction;
The counterweight is engaged with the rear part of the swivel base by moving the counterweight downward by the counterweight support mechanism and moving toward the swivel base side, and the state in which the counterweight is engaged with the rear part of the swivel base Counter weight engaging means for releasing the engagement between the rear portion of the swivel base and the counter weight by moving the counter weight upward and moving the counter weight toward the opposite side of the swivel base. A mobile crane counterweight attachment / detachment device. The counterweight support mechanism is
A stand for supporting the counterweight from below;
A link mechanism for moving the gantry downward and simultaneously moving the cradle to the swivel side, and simultaneously moving the gantry to the opposite side of the swivel; and
The counterweight attaching / detaching device for a mobile crane according to claim 1, further comprising a cylinder for operating the link mechanism. The link mechanism is
A first link member provided on each of the front and rear sides of the left and right sides of the gantry to connect the vehicle and the gantry;
The mobile crane according to claim 2, further comprising: a second link member that connects the first link members disposed in the front and rear directions to each other and simultaneously operates the first link members disposed in the front and rear directions. Counterweight attachment and detachment device. The counterweight engaging means is
An engaging pin extending in the left-right direction provided at the rear of the swivel;
4. An engagement hook provided on a side surface of the counterweight and detachably engaged with the engagement pin from above. The counterweight attaching / detaching device for the mobile crane as described.   A connection fixing means is provided between the rear portion of the swivel base and the side surface of the counterweight, and connects and fixes the swivel base and the counterweight in a state where an engagement hook is engaged with the engagement pin. The counterweight attaching / detaching device for a mobile crane according to claim 4.   6. An engaging portion capable of positioning the counterweight with respect to the gantry by providing the counterweight to be engaged with the upper surface of the gantry. 2. A counterweight attaching / detaching device for a mobile crane according to item 1.

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