JP2020029320A - Counterweight attaching/detaching device - Google Patents

Abstract

To ensure fixing of a counterweight on a swivel base, and to make compact an operation area of the swivel base during work.SOLUTION: A counterweight attaching/detaching device 60 comprises: first and second engaging arms 73, 74 that can rotate to a retreating attitude where they are retreated to the lateral side of a swivel base 31 and an engaging attitude where they project behind the swivel base 31 to be engaged with a counterweight 40; an elongation cylinder 75 that is provided between the engaging arms 73, 74, contracted to rotate the engaging arms 73, 74 to the retreating attitude, elongated to rotate the engaging arms 73, 74 from the retreating attitude to the engaging attitude, and further elongated to lift the counterweight 40 by the engaging arms 73, 74; a locking mechanism 63 for locking the first engaging arm 73 in a lifting attitude where the counterweight 40 is lifted; and a rotation regulation member 76 that regulates rotation of the second engaging arm 74 to the retreating attitude when the first engaging arm 73 is in the lifting attitude.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a counterweight attachment / detachment device for attaching / detaching a counterweight to / from a swivel of a crane.

  In general, a crane vehicle has a turntable mounted on a body frame, and a telescopic boom device is mounted on the turntable. The boom device can perform a swiveling operation via a swivel table in addition to the telescopic operation. A base end of the boom device is movably connected to the swivel base. The boom device can also perform an undulating operation. Usually, the boom device is provided with a winch, and a wire drum and its driving device are provided at a predetermined position of the swivel table (typically, at a position adjacent to the base end of the boom device). A counterweight may be attached to the rear end of the swivel base, and the counterweight is attached to and detached from the swivel base via a counterweight attaching / detaching device. Therefore, there are many design restrictions in arranging the winch and the counterweight attaching / detaching device in the vicinity of the base end of the boom device and in the space at the rear end of the swivel base, and the functional components such as the winch do not interfere with each other. There is a request that it must be laid out.

  For example, in a counterweight attaching / detaching device disclosed in Patent Document 1, an upper arm and a lower arm are provided on a swivel base, and these are driven by a hydraulic cylinder. By operating the hydraulic cylinder, the upper arm and the lower arm engage with the counterweight, and lift up and fix behind the swivel. However, in this type of counterweight attachment / detachment device, since the hydraulic cylinder and each arm are driven so as to protrude to the rear of the swivel base, the counterweights are also arranged to protrude further rearward from the rear end of the swivel base. Is done. For this reason, there is a disadvantage that the operation area of the swivel table during the operation is increased.

  The counterweight attachment / detachment device disclosed in Patent Literature 2 includes a link that engages with the counterweight and a hydraulic cylinder that drives the link, on the side of the swivel. Specifically, as shown in FIG. 1 of the document, an upper fuselage side link 11 and a lower fuselage side link 21 are arranged on both sides of the swivel base, and a hydraulic cylinder 16 connects them. When the hydraulic cylinder 16 is extended, the two links 11, 21 are engaged with the counterweight, lift up and fix. Since the links 11, 21 and the hydraulic cylinder 16 are laid out compactly on the side of the swivel table, the above-mentioned inconvenience is solved.

Japanese Patent No. 2796950 JP 2018-58693 A

  By the way, in the counterweight attaching / detaching device disclosed in the same document, when the operating pressure of the hydraulic cylinder 16 decreases for some reason, the hydraulic cylinder 16 contracts, and each of the links 11 and 21 rotates in a direction to separate from the counterweight. , The counterweight may fall. Therefore, it is desirable to provide a lock mechanism that regulates the rotation of each of the links 11 and 21 with the counterweight lifted up. However, since a wire drum or the like is arranged around the lower body link 21 based on the above request (see FIG. 2 of the same document), it is difficult to arrange a lock mechanism around the lower body link 21. There is a major problem in layout, and it is virtually impossible to provide a lock mechanism for locking the lower link 21 on the body side. Then, only the fuselage-side upper link 11 is locked, and when the operating pressure of the hydraulic cylinder 16 decreases as described above, only the fuselage-side lower link 21 rotates to disengage from the counterweight, and the counterweight is It is in a state of being suspended only by the body-side upper link 11. The counterweight suspended from the body-side upper link 11 may swing toward the swivel table, and in some cases, the wire drum or the like may interfere with the counterweight and be damaged.

  In order to fix the lower body link 21, for example, a hydraulic cylinder may be separately provided in the lower link 21 instead of the lock mechanism. Alternatively, it is conceivable to separately provide a hydraulic cylinder for connecting the swivel table and the counterweight. However, arranging such a hydraulic cylinder in the vicinity of the base end of the boom device or at the rear end of the swivel has the above-described layout problems, and is extremely difficult in design.

  The present invention has been made under such a background, and an object of the present invention is to enable a counterweight to be securely fixed on a swivel base, and to reduce the operating area of the swivel base during work. An object of the present invention is to provide a counterweight attaching / detaching device.

  (1) A counterweight attachment / detachment device according to the present invention attaches / detaches a counterweight to / from a swivel of a crane. The counterweight attachment / detachment device according to the present invention is located at a side of the swivel base, and is in a retracted posture retracted to the side of the swivel base. A first engagement arm that pivots between a mating position and a lift-up position that lifts up the counterweight, and a retreat position that is located on a side of the turntable and retracted to the side of the turntable. And a second engagement arm that projects between the first and second engagement arms and that rotates between an engagement position that projects rearward of the turntable and engages with the counterweight. A telescopic cylinder that rotates the first engagement arm and the second engagement arm by expanding and contracting, a lock mechanism that locks the first engagement arm in the lift-up position, the first engagement arm, Second engagement arm Interposed between, provided when the first engaging arm is the lift-up position, and the rotation restricting member in which the second engaging arm is restricted from pivoting toward the retracted position, the.

  According to this configuration, while the lock mechanism locks the first engagement arm in the lift-up posture, when the first engagement arm is in the lift-up posture, the rotation of the second engagement arm toward the evacuation posture is performed. The movement can be restricted by the rotation restricting member. Therefore, there is no need to provide a mechanism similar to the lock mechanism for locking the first engagement arm to lock the second engagement arm.

  The rotation restricting member is interposed between the first engagement arm and the second engagement arm. Therefore, if there is a space even on the first engagement arm side of the second engagement arm, the rotation restricting member can be arranged. Therefore, a space for disposing a member for restricting the rotation of the second engagement arm in the opposite direction is unnecessary on the side other than the first engagement arm side of the second engagement arm.

  (2) A counterweight attachment / detachment device according to the present invention is disposed along the left-right direction of the swivel table, and includes a first support shaft rotatably supporting the first engagement arm; A second support shaft provided below the shaft and arranged in parallel with the first support shaft, and rotatably supporting the second engagement arm. The first engagement arm changes its posture to the engagement posture by rotating in the predetermined direction from the retracted posture, and changes its posture to the lift-up posture by rotating in the predetermined direction from the engagement posture. . The second engagement arm changes its attitude to the engagement attitude by rotating in the predetermined direction from the retracted attitude. The telescopic cylinder changes the posture of the first engagement arm and the second engagement arm to the retracted posture by contracting, and extends the first engagement arm and the second engagement arm by elongating. The posture is changed from the evacuation posture to the engagement posture, and further extended to change the posture of the first engagement arm to the lift-up posture, and to rotate the second engagement arm by a predetermined angle in an opposite predetermined direction. . The rotation restricting member restricts the rotation of the second engagement arm in the opposite predetermined direction when the first engagement arm is in the lift-up posture.

  According to this configuration, while the lock mechanism locks the first engagement arm in the lift-up posture, when the first engagement arm is in the lift-up posture, the second engagement arm rotates counterclockwise. Can be restricted by the rotation restricting member. Therefore, there is no need to provide a mechanism similar to the lock mechanism for locking the first engagement arm to lock the second engagement arm.

  (3) The counterweight attachment / detachment device according to the present invention, wherein one of the first engagement arm or the second engagement arm, the predetermined engagement arm, or one of the rotation restricting members has an elongated hole. ing. The other of the predetermined engagement arm or the rotation restricting member has a protrusion inserted into the elongated hole. When the first engagement arm is in the lift-up posture, the protrusion is located at one end of the elongated hole. When the first engagement arm and the second engagement arm are in the engagement posture, the protrusion is located closer to the other end than the one end of the elongated hole. The posture of the second engagement arm changes from the engagement posture to the retracted posture as the protrusion moves in the direction from the other end to the one end.

  According to this configuration, when the first engagement arm is in the lift-up posture, the protrusion and the elongated hole abut at one end, thereby restricting the rotation of the second engagement arm in the opposite predetermined direction. be able to.

  (4) The first engagement arm includes the protrusion. The rotation restricting member has the elongated hole.

  According to this configuration, the elongated hole is provided near the first engagement arm. In other words, no long hole is provided near the second engagement arm. Therefore, it is possible to prevent at least a part of the space around the second engagement arm from being occupied by the elongated hole. Thereby, a large space for disposing a wire drum or the like can be secured around the second engagement arm.

  (5) The distance between the connection position of the first engagement arm with the telescopic cylinder and the first support shaft is equal to the distance between the connection position of the second engagement arm with the telescopic cylinder and the second support shaft. Longer than the distance.

  According to this configuration, the torque at which the first engagement arm rotates in the predetermined direction from the engagement posture is larger than the torque at which the second engagement arm rotates in the predetermined direction from the engagement posture. Therefore, the posture of the first engagement arm can be changed from the engagement posture to the lift-up posture, and the second engagement arm can be rotated in the opposite predetermined direction from the engagement posture, by the difference in the torque.

  (6) The rotation restricting member includes a first portion extending from a connection position with the first engagement arm in a direction in contact with a rotation direction of the first engagement arm.

  According to this configuration, when the rotation restricting member is moved by the rotation of the first engagement arm, the torque of the first engagement arm can efficiently act on the rotation restricting member. Thus, the torque of the first engagement arm required to move the rotation restricting member can be reduced.

  (7) The rotation restricting member includes a second portion extending from a connection position with the second engagement arm in a direction in contact with a rotation direction of the second engagement arm.

  According to this configuration, when the rotation restricting member is moved by the rotation of the second engagement arm, the torque of the second engagement arm can efficiently act on the rotation restricting member. Thereby, the torque of the second engagement arm necessary for moving the rotation restricting member can be reduced.

  (8) The rotation restricting member extends linearly from a connection position with the first engagement arm to a connection position with the second engagement arm.

  According to this configuration, the space occupied by the rotation restricting member can be reduced.

  (9) The first engagement arm engages with the counterweight from below. The second engagement arm is engaged with the counterweight from above.

  According to this configuration, since the first engagement arm and the second engagement arm engage with the counterweight in the opposite direction, the posture of the counterweight engaged by the first engagement arm and the second engagement arm is changed. Can be stabilized.

  ADVANTAGE OF THE INVENTION According to the counterweight attaching / detaching apparatus which concerns on this invention, a counterweight can be reliably fixed on a swivel base, and the working area of the swivel base at the time of work can be made compact.

FIG. 1 is a perspective view of a rough terrain crane 10. FIG. 2 is a side view of the rough terrain crane 10. FIG. 3 is a perspective view of the counterweight attaching / detaching device 60 and its peripheral portion. FIG. 4 is a side view of the lock mechanism 63 and its peripheral portion. FIG. 5 is a side view of the front part of the rough terrain crane 10, in a state in which the mounting base 51 is supported. FIG. 6 is a side view of the front part of the rough terrain crane 10, in a state where the body 51 and the counterweight 40 are supported. FIG. 7 is a side view of the front portion of the rough terrain crane 10, in which the counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engagement arm 73 and the second engagement arm 74 are in the retracted posture. . FIG. 8 is a side view of the front portion of the rough terrain crane 10 in a state where the counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engagement arm 73 and the second engagement arm 74 are in the engagement posture. is there. FIG. 9 is a side view of the front portion of the rough terrain crane 10, in which the counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engagement arm 73 is in a lift-up posture. FIG. 10 is a side view of the front portion of the rough terrain crane 10 in the modification, in which the counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engagement arm 73 and the second engagement arm 74 are in the retracted posture. State. FIG. 11 is a side view of the front portion of the rough terrain crane 10 in which the second engaging arm 74 has the concave portion 746. The counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engaging arm 73 and the second The engagement arm 74 is in the retracted posture. FIG. 12 is a side view of the front part of the rough terrain crane 10 in which the second engaging arm 74 has the concave portion 746. The counterweight attaching / detaching device 60 and the counterweight 40 face each other, and the first engaging arm 73 lifts up. This is the posture state.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Note that this embodiment is merely an embodiment of the present invention, and it is needless to say that the embodiment may be changed without changing the gist of the present invention.

  Further, in the present embodiment, the vertical direction is defined as the vertical direction 7, and the longitudinal direction 8 of the rough terrain crane 10 is defined with the traveling direction of the rough terrain crane 10 being the front of the horizontal direction, and the vertical direction 7 and the longitudinal direction 8 are defined. Is defined as the left-right direction 9 of the rough terrain crane 10. Right and left are defined when the rough terrain crane 10 is viewed from the rear to the front.

[Rough terrain crane 10]

  As shown in FIGS. 1 and 2, the rough terrain crane 10 according to the present embodiment includes a lower traveling body 20 and an upper working body 30 mounted on the lower traveling body 20. The rough terrain crane 10 is an example of the “crane” described in the claims. Specific examples of the crane are not limited to the rough terrain crane 10, and may be, for example, an all terrain crane, a loading truck crane, or the like.

[Lower traveling body 20]

  As shown in FIGS. 1 and 2, the lower traveling body 20 travels by a driving force of an engine (not shown) transmitted via a transmission (not shown).

  The lower traveling body 20 travels by operating various operation units such as a steering wheel, an accelerator pedal, and a brake pedal installed in the cabin 34 by an operator.

  The lower traveling body 20 has outriggers 28 and 29. The outriggers 28 and 29 can change state between an extended state in which the outriggers 28 and 29 are in contact with the ground at a position extending in the left-right direction 9 from the lower traveling body 20 and a retracted state in which the outriggers are stored in the lower traveling body 20 while being separated from the ground. It is. 1 and 2, the outriggers 28 and 29 are in a retracted state. The outriggers 28 and 29 are in an extended state when the upper working body 30 operates. Thereby, the posture of the rough terrain crane 10 is stabilized. On the other hand, the outriggers 28 and 29 are in the retracted state when the lower traveling body 20 travels.

[Upper working body 30]

  As shown in FIGS. 1 and 2, the upper working body 30 includes a swivel 31, a telescopic boom 32, a cabin 34, and a counterweight attaching / detaching device 60.

  The swivel base 31 is rotatably supported by the lower traveling body 20 via a swivel bearing (not shown). The telescopic boom 32 is supported by the swivel base 31 so as to be able to undulate and extend. A hook (not shown) is provided at the distal end of the telescopic boom 32. The hook can be hung by a rope extending downward from the distal end of the telescopic boom 32.

  In addition, since the swivel base 31 turns, the front and rear of the swivel base 31 may not coincide with the front and rear of the rough terrain crane 10 depending on the turning state of the swivel base 31. Therefore, in the following description, the side of the swivel base 31 where the cabin 34 is provided is referred to as the front side of the swivel base 31, and the side of the swivel base 31 where the counterweight attaching / detaching device 60 is provided is referred to as the rear side of the swivel base 31. , The front-back direction 4 of the swivel base 31 is defined. A direction orthogonal to the up-down direction 7 and the front-back direction 4 is defined as the left-right direction 5 of the swivel base 31. The right and left sides of the swivel base 31 are defined when the swivel base 31 is viewed from behind (when viewed from the counterweight attaching / detaching device 60 toward the cabin 34). Further, in the following description, a state where the front side of the swivel base 31 and the front side of the rough terrain crane 10 coincide, that is, the state illustrated in FIGS. 1 and 2 is defined as the normal posture of the swivel base 31. . In the following, the description will be made on the assumption that the swivel base 31 is in the normal posture unless otherwise specified. Note that the vertical direction 7 of the rough terrain crane 10 and the swivel base 31 match regardless of the swivel state of the swivel base 31.

  The cabin 34 is provided at the front end in the front-rear direction 4 and turns integrally with the turntable 31. The cabin 34 is located above the front axle 25. The above-mentioned various operation units for running the lower traveling body 20 and various levers and operation panels for operating the upper working body 30 are provided in the cabin 34.

  The turntable 31 is turned by a turn motor (not shown). The telescopic boom 32 is raised and lowered by a raising and lowering cylinder (not shown), and is expanded and contracted by a telescopic cylinder (not shown). The hook (not shown) is raised and lowered by winding and unwinding the rope by the winch 35 (see FIG. 3). The winch 35 is provided at the rear end of the front-rear direction 4. The winch 35 is located above the rear axles 26, 27. The swing motor, the up / down cylinder, the telescopic cylinder, the winch 35, the actuator that operates the outriggers 28 and 29, and the telescopic cylinders 75 and 91 (see FIGS. 4 and 7) of the counterweight attaching / detaching device 60 described later are, for example, hydraulic actuators. It is. The rough terrain crane 10 drives each actuator by controlling the direction and flow rate of the supplied hydraulic oil. The actuator is not limited to the hydraulic type, but may be an electric type or the like.

[Overall configuration of counterweight attaching / detaching device 60]

  The counterweight attaching / detaching device 60 shown in FIG. 3 is a device for attaching / detaching the counterweight 40 (see FIGS. 1 and 2) to / from the swivel 31. 1 and 2 show a state where the counterweight 40 is mounted on the swivel base 31.

  As shown in FIG. 2, the counterweight attaching / detaching device 60 is provided at the rear end of the front-rear direction 4 and is supported by the swivel 31. The counterweight attachment / detachment device 60 is located above the rear axles 26 and 27.

  As shown in FIG. 3, the counterweight attachment / detachment device 60 includes attachment / detachment units 61 and 62 and a lock mechanism 63.

  The attachment / detachment portions 61 and 62 are provided in a pair on the left and right sides of the winch 35. The detachable unit 61 is provided at the right rear end of the swivel 31, and the detachable unit 62 is provided at the left rear end of the swivel 31. The attaching / detaching portion 61 can be engaged with the right column 44 of the frame 41 of the counterweight 40 (see FIG. 1). The attaching / detaching portion 62 can be engaged with the left column 44 of the frame 41 of the counterweight 40 (see FIG. 1).

  The lock mechanism 63 is for locking the first engagement arms 73 (see FIGS. 7 to 9) of the attachment / detachment portions 61 and 62 to the lift-up posture shown in FIG.

[Counter weight 40]

  As shown in FIG. 7, the counterweight 40 includes a frame 41 and a weight 42.

  The frame 41 includes a bottom plate 43, a pair of columns 44 extending upward from the bottom plate 43, a first engagement portion 45, and a second engagement portion 46.

  As shown in FIG. 1, the pair of pillars 44 are provided at intervals in the left-right direction 5. The pillar 44 has a U-shape whose front is open in plan view. The pillar 44 includes a first plate 441 and a pair of second plates 442. The first plate 441 is a plate extending in the vertical direction 7 and the horizontal direction 5. The second plate 442 extends forward in the front-rear direction 4 from the right end and the left end of the first plate 441. The second plate 442 is a plate extending in the up-down direction 7 and the front-back direction 4.

  As shown in FIG. 7, the first engagement portion 45 is provided on an upper part of the pillar 44. The first engagement portion 45 is a rod-shaped member extending in the left-right direction 9 and connects the pair of second plates 442. The second engagement portion 46 is provided below the pillar 44. The second engagement portion 46 is a concave portion that is recessed downward, and extends in the left-right direction 9 from one of the pair of second plates 442 to the other. The first engaging portion 45 engages with the concave portion 736 of the first engaging arm 73 of the counterweight attaching / detaching device 60. The second engagement portion 46 engages with the bar member 743 of the second engagement arm 74 of the counterweight attaching / detaching device 60.

  The attachment / detachment mode between the counterweight 40 and the counterweight attachment / detachment device 60 is not limited to the above-described embodiment. For example, the first engaging portion 45 may be a concave portion, and the concave portion may engage with a bar member provided in the first engaging arm 73 instead of the concave portion 736. Also, for example, as shown in FIG. 11, the second engaging portion 46 may be a rod-shaped member, and the second engaging arm 74 may include a concave portion 746 instead of the rod member 743. Then, as shown in FIG. 12, the rod-shaped member may be engaged with the concave portion 746.

  The weight 42 is a plate-shaped member. The weight 42 is supported by the bottom plate 43 of the frame 41. The frame 41 can support a plurality of weights 42. When a plurality of weights 42 are supported by the frame 41, the weights 42 are arranged one above the other. The weight of the counterweight 40 is adjusted by the number of weights 42 supported by the frame 41. Each weight 42 is fixed to the frame 41 by a known means such as fitting.

[Removable parts 61, 62]

  As shown in FIGS. 3 and 7, each of the attachment / detachment portions 61 and 62 includes a first support shaft 71, a second support shaft 72, and a first engagement arm 73 (“predetermined engagement” described in the claims). Arm), a second engagement arm 74, a telescopic cylinder 75, and a rotation restricting member 76. The attachment / detachment unit 61 and the attachment / detachment unit 62 have the same configuration. Therefore, in the following, the configuration of the attachment / detachment unit 62 will be described in detail, and the explanation of the configuration of the attachment / detachment unit 61 will be omitted in principle and performed as needed.

  The first support shaft 71 and the first engagement arm 73 are located on the upper side of the right rear end of the swivel base 31. The first support shaft 71 extends along the left-right direction 5.

  As shown in FIG. 3, the first engagement arm 73 includes first plates 731 and 732 facing each other with an interval in the left-right direction 5, and a second plate 733 connecting the first plates 731 and 732. . The first plates 731 and 732 are plate-shaped members. The first plate 731 is provided outside the first plate 732 in the left-right direction 5 of the turntable 31.

  As shown in FIGS. 3 and 7, the first plates 731 and 732 are connected to the first support shaft 71 and are rotatably supported by the first support shaft 71. Thereby, the first engagement arm 73 can rotate around the first support shaft 71 to the retracted posture shown in FIG. 7, the engagement posture shown in FIG. 8, and the lift-up posture shown in FIG. It is.

  The first plates 731 and 732 include through holes 734 and 735 and a recess 736. The through hole 734 is for connecting the telescopic cylinder 75 to the first engagement arm 73. The penetrating member 93 (see FIG. 4) of the lock mechanism 63 can penetrate the through hole 735. The concave portion 736 is a rotating front end portion of the first plates 731 and 732 (a lower end portion in the retreating posture (see FIG. 7), and a rear end portion in the front-rear direction 4 in the engaging posture and the lift-up posture (FIGS. 8 and 9). See)). As shown in FIGS. 8 and 9, the recess 736 engages with the first engagement portion 45 of the counterweight 40.

  As shown in FIG. 7, the first plate 731 includes a convex portion 737 protruding leftward (outside of the swivel table 31 in the left-right direction 5). The protrusion 737 is inserted into the elongated hole 761 of the rotation restricting member 76.

  In the retracted position, the through-hole 734 is below the first support shaft 71, the through-hole 735 is above the first support shaft 71, the recess 736 is below the through-hole 734, and the protrusion 737 is the first support. It is ahead of the axis 71 in the front-rear direction 4.

  As shown in FIGS. 3 and 7, the second support shaft 72 and the second engagement arm 74 are located at a lower portion on the side of the right rear end of the swivel base 31. The second support shaft 72 extends along the left-right direction 5. That is, the second support shaft 72 is arranged parallel to the first support shaft 71.

  As shown in FIG. 3, the second engagement arm 74 includes plates 741 and 742 facing each other at intervals in the left-right direction 5, and a bar member 743 connecting the plates 741 and 742. The plate 741 is provided outside the plate 742 in the left-right direction 5.

  As shown in FIG. 7, the plates 741 and 742 are connected to the second support shaft 72 and are rotatably supported by the second support shaft 72. Thereby, the second engagement arm 74 is rotatable around the second support shaft 72 to the retracted posture shown in FIG. 7 and the engagement posture shown in FIG.

  Each of the plates 741 and 742 has a through hole 744. The through hole 744 is for connecting the telescopic cylinder 75 to the second engagement arm 74.

  The plate 741 includes a convex portion 745 protruding leftward (outside of the swivel table 31 in the left-right direction 5). The protrusion 745 is connected to the rotation restricting member 76.

  The rod member 743 is provided at the pivotal tip of the plates 741 and 742 (the upper end in the retracted posture (see FIG. 7) and the rear end in the front-rear direction 4 in the engaged posture (see FIG. 8)). . As shown in FIGS. 8 and 9, the bar member 743 is engaged with the second engagement portion 46 of the counterweight 40.

  As shown in FIG. 7, in the retracted position, the through hole 744 is above the second support shaft 72, the protrusion 745 is above the through hole 744, and the bar member 743 is above the protrusion 745.

  As shown in FIGS. 3 and 7, the telescopic cylinder 75 is provided between the first engagement arm 73 and the second engagement arm 74 in the vertical direction 7. That is, the telescopic cylinder 75 is interposed between the first engagement arm 73 and the second engagement arm 74.

  The telescopic cylinder 75 includes a cylindrical main body 751 and a piston rod 752 that expands and contracts with respect to the main body 751. The main body 751 has a projection 753 at the lower end. The main body 751 is connected to the second engagement arm 74 by inserting the protrusion 753 into the through hole 744. The piston rod 752 has a protrusion 754 at the tip. The piston rod 752 is connected to the first engagement arm 73 by inserting the protrusion 754 into the through hole 734.

  As shown in FIG. 7, the distance D1 between the position of the protrusion 754 (the connection position of the first engagement arm 73 with the telescopic cylinder 75) and the first support shaft 71 is determined by the position of the protrusion 753 (the second engagement arm 74). At the connection position with the telescopic cylinder 75) and the second support shaft 72.

  Note that, contrary to the present embodiment, the main body 751 may be connected to the first engagement arm 73, and the piston rod 752 may be connected to the second engagement arm 74.

  As shown in FIGS. 3 and 7, the rotation restricting member 76 is provided between the first engagement arm 73 and the second engagement arm 74 in the vertical direction 7. That is, the rotation restricting member 76 is interposed between the first engagement arm 73 and the second engagement arm 74.

  The rotation restricting member 76 is a flat plate-shaped member that extends straight. One end (upper end) of the rotation restricting member 76 is connected to the first engagement arm 73. The other end (lower end) of the rotation restricting member 76 is connected to the second engagement arm 74. As described above, the rotation restricting member 76 linearly extends from the connection position with the first engagement arm 73 to the connection position with the second engagement arm 74.

  The rotation restricting member 76 has an elongated hole 761 at its upper end. The long hole 761 extends along the longitudinal direction of the rotation restricting member 76. The rotation restricting member 76 is connected to the first engagement arm 73 by inserting the protrusion 737 into the elongated hole 761. The convex portion 737 is relatively movable with respect to the elongated hole 761. The rotation restricting member 76 is rotatable about the projection 737 with respect to the first engagement arm 73.

  The rotation restricting member 76 has a through hole (not shown) at its lower end. The rotation restricting member 76 is connected to the second engagement arm 74 by inserting the convex portion 745 into the through hole. The rotation restricting member 76 is rotatable about the protrusion 745 with respect to the second engagement arm 74.

[Lock mechanism 63]

  As shown in FIG. 3, the lock mechanism 63 is provided between the attaching / detaching portions 61 and 62 in the left-right direction 5. The lock mechanism 63 is located on the upper side of the swivel base 31.

  As shown in FIG. 4, the lock mechanism 63 includes a telescopic cylinder 91, penetrating members 92 and 93, connecting members 94 and 95, and coil springs 96 and 97.

  The telescopic cylinder 91 is disposed so as to extend in the left-right direction 5. The telescopic cylinder 91 includes a cylindrical main body 911 and a piston rod 912 that expands and contracts with respect to the main body 911.

  The penetrating member 92 is a rod-shaped member extending in the left-right direction 5, and is provided on the left side of the through hole 735 of the first engaging arm 73 of the attaching / detaching portion 61. The penetrating member 92 can penetrate through the through hole 735. The connecting member 94 connects the main body 911 of the telescopic cylinder 91 and the penetrating member 92. The coil spring 96 can bias the penetrating member 92 to the right, that is, the urging member 92 toward the first engagement arm 73 of the attaching / detaching portion 61.

  The penetrating member 93 is a rod-shaped member extending in the left-right direction 5, and is provided to the right of the through hole 735 of the first engaging arm 73 of the attaching / detaching portion 62. The penetrating member 93 can penetrate through the through hole 735. The connecting member 95 connects the piston rod 912 of the telescopic cylinder 91 and the penetrating member 93. The coil spring 97 can bias the penetrating member 93 to the left, that is, the penetrating member 93 toward the first engagement arm 73 of the attaching / detaching portion 62.

  When the first engagement arm 73 is in the lift-up posture shown in FIG. 9, the through hole 735 of the attaching / detaching portion 61 and the penetrating member 92 face in the left-right direction 5, and the through hole 735 of the attaching / detaching portion 62 and the penetrating member 93 Oppose each other in the left-right direction 5. Thereby, as shown in FIG. 4, the penetrating member 92 penetrates the through hole 735 of the attaching / detaching portion 61 by the urging force of the coil spring 96, and the penetrating member 93 becomes the through hole 735 of the attaching / detaching portion 62 by the urging force of the coil spring 97. Penetrate through. Thereby, the first engagement arm 73 is locked in the lift-up posture.

  When the telescopic cylinder 91 is actuated and contracted, the penetrating member 92 moves leftward against the urging force of the coil spring 96, and the penetrating member 93 moves rightward against the urging force of the coil spring 97. Thereby, the lock of the first engagement arm 73 is released.

  Note that the configuration of the lock mechanism 63 is not limited to the configuration described above, and various known configurations can be employed.

[Removal operation of counter weight 40]

  Hereinafter, the mounting operation of the counterweight 40 on the swivel base 31 by the counterweight attaching / detaching device 60 will be described.

  First, as shown in FIG. 5, the mounting base 51 is disposed on the upper surface 21 of the lower traveling body 20 ahead of the swivel base 31 in the front-rear direction 8. The mounting table 51 is a table for supporting the counterweight 40. The cradle 51 is carried by a truck or the like different from the rough terrain crane 10, is suspended by a hook of the rough terrain crane 10, and is disposed on the upper surface 21. The mounting base 51 may be arranged on the upper surface 21 by a crane other than the rough terrain crane 10 or the like.

  The projections 22 provided on the upper surface 21 are inserted into holes (not shown) provided on the lower surface of the mounting base 51, whereby the mounting base 51 is positioned. The means for positioning the mounting base 51 is not limited to the means using the projections 22 and the holes.

  Next, as shown in FIG. 6, the counterweight 40 is supported by the mounting base 51. The counterweight 40 is transported by a truck or the like different from the rough terrain crane 10, is suspended by a hook of the rough terrain crane 10, and is placed on the mounting base 51. The counterweight 40 may be arranged on the mounting base 51 by a crane other than the rough terrain crane 10 or the like.

  The projection (not shown) provided on the upper surface of the mounting base 51 is inserted into a hole (not shown) provided in the bottom plate 43 of the frame 41 of the counterweight 40, whereby the counterweight 40 is positioned. The means for positioning the counterweight 40 is not limited to the one using the projection and the hole.

  Next, the swivel base 31 is turned so that the counterweight attaching / detaching device 60 is located on the front side of the rough terrain crane 10 and the cabin 34 is located on the rear side of the rough terrain crane 10. That is, the swivel base 31 is swung such that the rear side of the swivel base 31 is located in front of the rough terrain crane 10 and the front side of the swivel base 31 is located in the rear side of the rough terrain crane 10. As a result, as shown in FIG. 7, the counterweight attaching / detaching device 60 and the counterweight 40 face each other in the front and rear directions 4 and 8.

  At this time, the first engagement arm 73 and the second engagement arm 74 are in the retracted posture. In the retracted posture, the first engagement arm 73 and the second engagement arm 74 are in a state of extending vertically. Thus, the first engagement arm 73 and the second engagement arm 74 are in a state where they do not protrude from the swivel base 31. That is, the first engagement arm 73 and the second engagement arm 74 in the retracted posture are retracted to the side of the turntable 31 with respect to the counterweight 40. In the retracted posture, the convex portion 737 is located at the lower end 77 of the elongated hole 761 of the rotation restricting member 76 (an example of “one end of the elongated hole” described in the claims).

  In the retracted position, the lock mechanism 63 (see FIG. 4) does not lock the first engagement arm 73. More specifically, the penetrating members 92 and 93 do not face the through hole 735 of the first engagement arm 73 in the retracted posture. Therefore, the penetrating members 92 and 93 urged by the coil springs 96 and 97 abut the first plate 732 of the first engagement arm 73 and are not inserted into the through holes 735. Therefore, in the retracted posture, the first engagement arm 73 is not locked by the lock mechanism 63 and can rotate.

  Next, the counterweight attaching / detaching device 60 is operated. That is, the telescopic cylinder 75 is extended.

  As the telescopic cylinder 75 is extended, first, the second engagement arm 74 is rotated clockwise in FIG. 7 so that the rotation tip (rod member 743) moves downward. The clockwise rotation direction of the second engagement arm 74 is an example of the “predetermined direction” described in the claims. By the rotation of the second engagement arm 74, the rotation restricting member 76 is pulled by the second engagement arm 74 and moves downward. As a result, the convex portion 737 moves from the lower end 77 of the elongated hole 761 to the upper end 78 (an example of “the other end of the elongated hole” described in the claims), that is, in the direction of the arrow 81. It moves relatively to the elongated hole 761.

When the convex portion 737 reaches the upper end portion 78 of the elongated hole 761, it cannot move further in the direction of the arrow 81 relative to the elongated hole 761. When the telescopic cylinder 75 further extends in this state,
The first engagement arm 73 rotates counterclockwise in FIG. 7 so that the rotation tip (recess 736) moves upward. The counterclockwise rotation direction of the first engagement arm 73 is an example of the “predetermined direction” described in the claims. At this time, the clockwise rotation of the second engagement arm 74 is continued. That is, the first engagement arm 73 and the second engagement arm 74 rotate in opposite directions. By this rotation, as shown in FIG. 8, the concave portion 736 of the first engagement arm 73 engages with the first engagement portion 45 of the counterweight 40 from below, and the bar member 743 of the second engagement arm 74 is moved. It engages with the second engaging portion 46 of the counterweight 40 from above. Thus, the counterweight attaching / detaching device 60 is in a state where the counterweight 40 is held.

  The posture of the first engagement arm 73 and the second engagement arm 74 at this time is the engagement posture. In the engagement posture, the first engagement arm 73 and the second engagement arm 74 are in a state of extending forward and backward in the front-rear direction 4. Accordingly, the first engagement arm 73 and the second engagement arm 74 are in a state of protruding rearward in the front-rear direction 4. In the engaging posture, the convex portion 737 is located at the upper end 78 of the elongated hole 761 of the rotation restricting member 76. Further, as in the retracted posture, the lock mechanism 63 (see FIG. 4) does not lock the first engagement arm 73 in the engaged posture.

  In the state shown in FIG. 8, the first engagement arm 73 is engaged with the counterweight 40 from below and the second engagement arm 74 is engaged with the counterweight 40 from above. The engagement arm 73 and the second engagement arm 74 cannot rotate in opposite directions. Here, as described above, the distance D1 is longer than the distance D2 (see FIG. 7). Therefore, when the telescopic cylinder 75 is further extended in the state shown in FIG. 8, the torque at which the first engagement arm 73 rotates counterclockwise in FIG. It becomes larger than the torque that rotates around. Thus, when the telescopic cylinder 75 is further extended in the state shown in FIG. 8, both the first engagement arm 73 and the second engagement arm 74 rotate counterclockwise as shown in FIG. That is, while the rotation direction of the first engagement arm 73 is the same as when the posture changes from the retracted posture to the engaged posture, the rotational direction of the second engagement arm 74 is changed from the retracted posture to the engaged posture. The direction is opposite to that when the posture changes. The counterclockwise rotation direction of the second engagement arm 74 is an example of the “predetermined direction” described in the claims.

  When both the first engagement arm 73 and the second engagement arm 74 rotate counterclockwise as shown in FIG. 8, the counterweight 40 is lifted up (see FIG. 9).

  When the first engagement arm 73 rotates from the position shown in FIG. 8 to the position shown in FIG. 9, that is, when the first engagement arm 73 changes its posture from the engaging posture to the lift-up posture, the penetrating members 92, 93 (See FIG. 4) is in a state of facing left and right with the through hole 735 of the first engagement arm 73. Therefore, the penetrating members 92 and 93 urged by the coil springs 96 and 97 are inserted into the through holes 735. Thus, the first engagement arm 73 in the lift-up posture is locked by the lock mechanism 63.

  Also, while the second engagement arm 74 rotates from the position shown in FIG. 8 to the position shown in FIG. 9, that is, while the first engagement arm 73 changes its posture from the engagement posture to the lift-up posture. The second engagement arm 74 rotates counterclockwise by a predetermined angle θ (see FIG. 9). During this rotation, the rotation restricting member 76 is pushed upward by the second engagement arm 74 and moves upward. As a result, the convex portion 737 moves from the upper end portion 78 of the elongated hole 761 toward the lower end portion 77, that is, in the direction of the arrow 82 (the opposite direction to the arrow 81), relative to the elongated hole 761.

  In order for the second engagement arm 74 to rotate counterclockwise in FIG. 9 when the first engagement arm 73 is in the lift-up position, the rotation restricting member 76 pushed by the second engagement arm 74 needs to be rotated. Need to move up. Here, when the first engagement arm 73 is in the lift-up posture, the protrusion 737 is located at the lower end 77 of the elongated hole 761 (see FIG. 9). Therefore, in order for the rotation restricting member 76 to move upward, it is necessary that the rotation restricting member 76 pushes the protrusion 737 to move it upward. However, since the first engagement arm 73 is locked by the lock mechanism 63, the protrusion 737 cannot move. Therefore, the rotation restricting member 76 cannot move upward. Therefore, the second engagement arm 74 cannot rotate counterclockwise in FIG. That is, the posture of the second engagement arm 74 cannot be changed from the posture shown in FIG. 9 to the retracted posture shown in FIG. As described above, the rotation restricting member 76 restricts the second engagement arm 74 from rotating counterclockwise in FIG. 9 when the first engagement arm 73 is in the lift-up posture.

  After the counterweight 40 is lifted up, the mounting base 51 is removed from the lower traveling body 20.

  Hereinafter, an operation of lowering the counterweight 40 on the swivel base 31 by the counterweight attaching / detaching device 60 will be described.

  First, as in the case where the counterweight 40 is mounted on the swivel base 31, the mounting base 51 is disposed on the lower traveling body 20 (see FIG. 5).

  Next, as shown in FIG. 9, the swivel base 31 is turned so that the counterweight attaching / detaching device 60 is located on the front side of the rough terrain crane 10 and the cabin 34 is located on the rear side of the rough terrain crane 10. At this time, the first engagement arm 73 and the second engagement arm 74 are in the lift-up posture.

  Next, the telescopic cylinder 91 (see FIG. 4) is reduced. As a result, the penetrating member 92 moves to the left and the penetrating member 93 moves to the right, so that the penetrating members 92 and 93 come out of the through holes 735. As a result, the lock of the first engagement arm 73 to the lift-up posture by the lock mechanism 63 is released. After the lock is released, the telescopic cylinder 91 is extended to its original state.

  Next, the telescopic cylinder 75 is reduced. Here, since the distance D1 is longer than the distance D2 (see FIG. 7), the torque at which the first engagement arm 73 rotates clockwise as shown in FIG. It becomes larger than the torque that rotates counterclockwise. Thus, when the telescopic cylinder 75 is reduced in the state shown in FIG. 9, both the first engagement arm 73 and the second engagement arm 74 rotate clockwise as shown in FIG.

  When both the first engagement arm 73 and the second engagement arm 74 rotate clockwise as shown in FIG. 9, the counterweight 40 moves downward and is supported by the mounting base 51 (see FIG. 8). . At this time, the first engagement arm 73 and the second engagement arm 74 are in the engagement posture.

  Also, while the second engagement arm 74 rotates from the position shown in FIG. 9 to the position shown in FIG. 8, that is, while the first engagement arm 73 changes posture from the lift-up posture to the engagement posture. The second engagement arm 74 rotates clockwise by a predetermined angle θ (see FIG. 9). During this rotation, the rotation regulating member 76 is pulled by the second engagement arm 74 and moves downward. As a result, the protrusion 737 moves from the lower end 77 of the elongated hole 761 toward the upper end 78, that is, in the direction of the arrow 81, relative to the elongated hole 761.

  When the first engagement arm 73 and the second engagement arm 74 are in the engagement posture and the counterweight 40 is supported by the mounting base 51, the second engagement arm 74 cannot rotate further clockwise. . When the telescopic cylinder 75 further contracts in this state, the second engagement arm 74 rotates counterclockwise in FIG. On the other hand, the first engagement arm 73 continues to rotate clockwise in FIG. That is, the first engagement arm 73 and the second engagement arm 74 rotate in opposite directions.

  By this rotation, the first engagement arm 73 and the second engagement arm 74 change their posture from the engaging posture (see FIG. 8) to the retracted posture (see FIG. 7). As described above, the telescopic cylinder 75 changes the posture of the first engagement arm 73 and the second engagement arm 74 to the retracted posture by contracting.

  Further, by this rotation, the engagement of the concave portion 736 of the first engagement arm 73 with the first engagement portion 45 is released. Further, the engagement of the rod member 743 of the second engagement arm 74 with the second engagement portion 46 is released. Thereby, the state in which the counterweight attaching / detaching device 60 holds the counterweight 40 is released.

  When the second engagement arm 74 rotates counterclockwise in FIG. 8, the rotation restricting member 76 is pushed upward by the second engagement arm 74 and moves upward. Thus, the convex portion 737 moves relatively from the upper end 78 of the elongated hole 761 to the lower end 77, that is, in the direction of the arrow 81, relative to the elongated hole 761. As described above, the posture of the second engagement arm 74 changes from the engagement posture to the retracted posture as the protrusion 737 moves from the upper end 78 to the lower end 77 of the elongated hole 761.

  Thereafter, the counterweight 40 is suspended by the hook of the rough terrain crane 10 and transported to a different truck from the rough terrain crane 10. The mounting base 51 is also carried to a truck or the like in the same manner as the counterweight 40.

[Effects of the present embodiment]

  According to the present embodiment, while the lock mechanism 63 locks the first engagement arm 73 in the lift-up posture, the second engagement is performed when the first engagement arm 73 is in the lift-up posture shown in FIG. The counterclockwise rotation of the arm 74 in FIG. 9 can be restricted by the rotation restricting member 76. Therefore, there is no need to provide a mechanism similar to the lock mechanism 63 for locking the first engagement arm 73 to lock the second engagement arm 74.

  The rotation restricting member 76 is interposed between the first engagement arm 73 and the second engagement arm 74. Therefore, if there is space even on the first engagement arm 73 side of the second engagement arm 74, the rotation restricting member 76 can be arranged. Therefore, the second engagement arm 74 is rotated counterclockwise in FIG. 9 on a side other than the first engagement arm 73 side, for example, to the right or left of the second engagement arm 74. A space for disposing a member for restricting rotation is unnecessary.

  Further, according to the present embodiment, when the first engagement arm 73 is in the lift-up posture, the convex portion 737 and the elongated hole 761 abut at the lower end portion 77, whereby the second engagement arm in FIG. Counterclockwise rotation can be restricted.

  Further, according to the present embodiment, the elongated hole 761 is provided near the first engagement arm 73. In other words, the elongated hole 761 is not provided near the second engagement arm 74. Therefore, it is possible to prevent at least a part of the space around the second engagement arm 74 from being occupied by the elongated hole 761. Thereby, a large space for disposing a wire drum or the like can be secured around the second engagement arm 74.

  According to the present embodiment, the torque at which the first engagement arm 73 rotates counterclockwise in FIG. 8 from the engagement posture shown in FIG. 8 is larger than the torque rotating clockwise in FIG. For this reason, the first engagement arm 73 can be changed from the engagement posture to the lift-up posture, and the second engagement arm 74 can be rotated counterclockwise in FIG. it can.

  Further, according to the present embodiment, since the rotation restricting member 76 extends linearly, the space occupied by the rotation restricting member 76 can be reduced.

  Further, according to the present embodiment, since the first engagement arm 73 and the second engagement arm 74 engage with the counterweight 40 in the opposite direction, the first engagement arm 73 and the second engagement arm 74 engage. The posture of the combined counterweight 40 can be stabilized.

[Modification]

  In the above embodiment, the rotation restricting member 76 linearly extends from the connection position with the first engagement arm 73 to the connection position with the second engagement arm 74. However, the shape of the rotation restricting member 76 is not limited to a linear shape, and may be curved or bent.

  For example, as shown in FIG. 10, the rotation restricting member 76 may include a first portion 101, a second portion 102, and a third portion 103.

  The first portion 101 has an elongated hole 761 at one end thereof, and is connected to the first engagement arm 73 via a convex portion 737. The first portion 101 extends from a connection position with the first engagement arm 73 (the position of the elongated hole 761 and the convex portion 737) in a direction in contact with the rotation direction of the first engagement arm 73.

  The second portion 102 is connected at one end thereof to the second engagement arm 74 via a convex portion 745. The second portion 102 extends from a connection position with the second engagement arm 74 (the position of the convex portion 745) in a direction in contact with the rotation direction of the second engagement arm 74.

  One end of the third portion 103 is connected to the other end of the first portion 101, and the other end of the third portion 103 is connected to the other end of the second portion 102.

  Note that the rotation restricting member 76 may be composed of the first portion 101 and the third portion 103. In this case, the third portion 103 extends linearly from the other end of the first portion 101 to the convex portion 745, for example. Further, the rotation restricting member 76 may be composed of the second portion 102 and the third portion 103. In this case, the third portion 103 extends linearly from the other end of the second portion 102 to the convex portion 737, for example.

  According to the above modification, when the rotation restricting member 76 is moved by the rotation of the first engagement arm 73, the torque of the first engagement arm 73 can be efficiently applied to the rotation restricting member 76. Similarly, when the rotation restricting member 76 is moved by the rotation of the second engagement arm 74, the torque of the second engagement arm 74 can be efficiently applied to the rotation restricting member 76. Thereby, the torque of the first engagement arm 73 and the second engagement arm 74 required for moving the rotation restricting member 76 can be reduced.

  In the above embodiment, the rotation restricting member 76 has the elongated hole 761 at the upper end and the through hole at the lower end. However, contrary to the above-described embodiment, the rotation restricting member 76 may include the through hole at the upper end and the elongated hole 761 at the lower end. Then, the protrusion 737 may be inserted into the through-hole, and the protrusion 745 may be inserted into the elongated hole 761. In this case, the second engagement arm 74 is an example of the “predetermined engagement arm” described in the claims.

  Further, the rotation restricting member 76 may have a long hole at both the upper end and the lower end. In this case, the projection 737 of the first engagement arm 73 is inserted into the elongated hole of the upper end of the rotation restricting member 76, and the projection 745 of the second engagement arm 74 is inserted into the lower end of the rotation restriction member 76. It is inserted in the long hole.

  In the above embodiment, the first engagement arm 73 and the second engagement arm 74 each have a convex portion, and the rotation restricting member 76 has a long hole and a through hole into which the convex portion is inserted. It is not limited to such a configuration. For example, contrary to the above embodiment, the first engagement arm 73 has one of a long hole and a through hole, and the second engagement arm 74 has the other of the long hole and the through hole. 76 may have a convex part. In this case, one of the first engagement arm 73 and the second engagement arm 74 that has the elongated hole is an example of the “predetermined engagement arm” described in the claims. Further, for example, the rotation restricting member 76 has a long hole 761 at the upper end thereof and a protrusion at the lower end thereof, while the first engagement arm 73 has a protrusion 737 inserted into the long hole 761. Further, the second engagement arm 74 may have a through hole inserted into the projection of the rotation restricting member 76.

  In the above embodiment, the elongated hole 761 penetrates the rotation restricting member 76, but the elongated hole 761 may be a groove that does not penetrate the rotation restricting member 76.

  The mutual positional relationship between the components (the through-hole 734, the through-hole 735, the concave portion 736, and the convex portion 737) of the first support shaft 71 and the first engagement arm 73 is the same as the positional relationship (FIG. 7). Further, the positional relationship among the respective components (the through-hole 744, the convex portion 745, and the bar member 743) of the second support shaft 72 and the second engagement arm 74 is the same as the positional relationship described in the above embodiment (see FIG. 7). The positional relationship shown).

  In the above embodiment, the counterweight attachment / detachment device 60 includes the two attachment / detachment portions 61 and 62 provided in a pair on the left and right sides of the winch 35, but the number of attachment / detachment portions is not limited to two. For example, the counterweight attachment / detachment device 60 may include three attachment / detachment units provided at intervals along the left-right direction 9.

4 Front-back direction 5 Left-right direction 7 Vertical direction 8 Front-back direction 9 Left-right direction 10 Rough terrain crane (crane)
31 swivel 40 counterweight 60 counterweight attaching / detaching device 71 first support shaft 72 second support shaft 73 first engagement arm 74 2 engagement arm 75 ··· telescopic cylinder 63 ··· lock mechanism 76 ··· rotation control member 77 ··· lower end 78 ··· upper end 101 ··· first part 102 ··· second part 737: convex portion 761: long hole

Claims (9)

A counterweight attachment / detachment device for attaching / detaching a counterweight to / from a swivel of a crane,
The retracted position is located on the side of the swivel table and retracted to the side of the swivel table, the engaging position projecting rearward of the swivel table and engaging with the counterweight, and lifting the counterweight up A first engagement arm that rotates between lift-up positions;
A fourth position, which is located on the side of the swivel table and rotates between a retracted position retracted to the side of the swivel table and an engaging position projecting rearward of the swivel table and engaging with the counterweight. Two engagement arms,
A telescopic cylinder interposed between the first engaging arm and the second engaging arm and extending and contracting to rotate the first engaging arm and the second engaging arm;
A lock mechanism for locking the first engagement arm in the lift-up position;
The second engagement arm is interposed between the first engagement arm and the second engagement arm, and when the first engagement arm is in the lift-up position, the second engagement arm rotates toward the retracted position. A counterweight attachment / detachment device comprising: A first support shaft arranged along the left-right direction of the swivel table and rotatably supporting the first engagement arm;
A second support shaft provided below the first support shaft and arranged in parallel with the first support shaft, and rotatably supporting the second engagement arm.
The first engagement arm changes its posture to the engagement posture by rotating in the predetermined direction from the retracted posture, and changes its posture to the lift-up posture by rotating in the predetermined direction from the engagement posture. ,
The second engagement arm changes its posture to the engagement posture by rotating in a predetermined direction from the retracted posture,
The telescopic cylinder changes the posture of the first engagement arm and the second engagement arm to the retracted posture by contracting, and extends the first engagement arm and the second engagement arm by elongating. The posture is changed from the evacuation posture to the engagement posture, and further extended to change the posture of the first engagement arm to the lift-up posture and to rotate the second engagement arm by a predetermined angle in a direction opposite to the predetermined direction. ,
2. The counterweight according to claim 1, wherein the rotation restricting member restricts the second engagement arm from rotating in the opposite predetermined direction when the first engagement arm is in the lift-up posture. Detachable device. One of the first engagement arm and the second engagement arm, the predetermined engagement arm, or one of the rotation restricting members has an elongated hole,
The predetermined engagement arm, or the other of the rotation regulating member, has a convex portion inserted into the elongated hole,
When the first engagement arm is in the lift-up posture, the protrusion is located at one end of the elongated hole,
When the first engagement arm and the second engagement arm are in the engagement posture, the protrusion is located closer to the other end than the one end of the elongated hole,
3. The counterweight attachment / detachment according to claim 2, wherein the second engagement arm changes its attitude from the engagement attitude to the retracted attitude by moving the projection in a direction from the other end toward the one end. apparatus. The first engagement arm includes the protrusion,
The counterweight attaching / detaching device according to claim 3, wherein the rotation restricting member includes the elongated hole.   The distance between the connection position of the first engagement arm with the telescopic cylinder and the first support shaft is longer than the distance between the connection position of the second engagement arm with the telescopic cylinder and the second support shaft. The counterweight attaching / detaching device according to claim 3 or 4.   The counter according to any one of claims 1 to 5, wherein the rotation restricting member includes a first portion extending from a connection position with the first engagement arm in a direction in contact with a rotation direction of the first engagement arm. Weight attachment / detachment device.   The counter according to any one of claims 1 to 6, wherein the rotation restricting member includes a second portion extending from a connection position with the second engagement arm in a direction in contact with a rotation direction of the second engagement arm. Weight attachment / detachment device.   The counterweight attachment / detachment device according to any one of claims 1 to 7, wherein the rotation restricting member extends linearly from a connection position with the first engagement arm to a connection position with the second engagement arm. . The first engagement arm engages the counterweight from below,
9. The counterweight attachment / detachment device according to claim 1, wherein the second engagement arm engages the counterweight from above.

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