JP6881128B2 - Construction machinery with gantry - Google Patents

Description

The present invention relates to a construction machine equipped with a gantry.

Conventionally, a construction machine provided with a gantry as disclosed in Patent Document 1 below is known. The gantry has a front leg, an upper rear leg, a lower rear leg, and a connecting portion. The gantry can be in a working state and a stored state. The working state is the state that the gantry takes when working with the construction machine, and the stored state is the state that the gantry takes when the construction machine is transported. In the working state, the upper hind legs and the lower hind legs extend along a substantially vertical line, and the front legs incline diagonally forward and downward. On the other hand, in the retracted state, the lower hind legs and the upper hind legs lie down while being folded, and the front legs lie down on the folded upper hind legs.

The construction machine includes a swivel frame as a base. The gantry further includes a connecting portion that connects the front leg and the upper rear leg to each other, and a connecting rod that connects the connecting portion to the swivel frame and holds a stored state. The connecting rod has an upper end portion connected to the connecting portion so as to be a rotation center of the connecting rod, and a lower end portion on which a pin insertion hole is formed. A pin insertion hole is also formed in the swivel frame, and the pin is inserted into the pin insertion hole in the retracted state to maintain the retracted state.

In such a construction machine, if the construction work is performed without fixing the lower end portion of the connecting rod, the connecting rod shakes and collides with the upper hind legs and the like, and the paint on the upper hind legs and the connecting rod collides with each other. May cause noise. Therefore, the gantry disclosed in Patent Document 1 includes an engaging pin provided as a shaft portion on the connecting rod and an engaging groove provided as a shaft holding portion on the upper rear leg. The engaging pin and the engaging groove are engaged with each other in the working state to prevent the connecting rod from swinging.

Japanese Unexamined Patent Publication No. 2011-37628

In the conventional construction machine described above, in order to prevent the connecting rod from shaking in the working state and prevent the connecting rod from colliding with the upper hind legs or the like, the operator attaches the engaging pin of the connecting rod to the upper hind legs. However, when the construction machine becomes large and the height of the gantry increases accordingly, the position of the engaging groove becomes high, and as a result, the operator causes the above-mentioned The work of engaging the engaging pin with the engaging groove becomes difficult.

An object of the present invention is to prevent a connecting member connecting the gantry and the swivel frame of the upper swivel body from colliding with the upper hind legs of the gantry in the working state of the gantry in order to hold the gantry in the retracted state. Therefore, the work of connecting the connecting portion of the connecting member to the bonded portion of the gantry can be easily performed by the operator even when the height of the gantry is increased.

In order to achieve the above object, for example, the length of the connecting member is increased so that the connecting portion of the connecting member is arranged at a lower position when the gantry is put into the working state, and the position of the connecting portion is provided. By providing the jointed portion of the gantry at a height position corresponding to the above, the operator can easily reach the jointed portion of the connecting member when the jointed portion of the gantry is connected to the jointed portion of the gantry. It is conceivable to make it easy.

However, in this case, when the gantry is stored, the effect of the connecting member holding the gantry in the retracted state is diminished, and the gantry in the stored state is lifted by vertical vibration or shaking generated during transportation of the upper swing body. Another problem arises that it cannot be prevented. Specifically, when the length of the connecting member is increased as described above, the connecting member connected to the swivel frame in the retracted state from the upper end of the connecting member connected to the tip of the front leg of the gantry. The distance to the lower end is increased, and as a result, the ability of the connecting member to anchor the tip of the front leg of the gantry to the swivel frame against the component of the upward force is reduced, and against the above-mentioned vibration and shaking. It becomes difficult to prevent the gantry in the stored state from rising and to hold the gantry in the stored state.

Therefore, the inventor of the present application invented the following construction machine in order to solve this problem.

The construction machine provided by the present invention has a lower main body, an upper swivel body having a swivel frame rotatably mounted on the lower main body, and the upper swivel body so as to be rotatable around an axis extending in the left-right direction. A front leg having a base end portion connected to the swivel frame and a tip end portion on the opposite side thereof, and a first upper end portion connected to the tip end portion so as to be rotatable around an axis extending in the left-right direction. An upper hind leg having a first lower end on the opposite side, a second upper end connected to the first lower end so as to be rotatable around an axis extending in the left-right direction, and a second on the opposite side. 2 A gantry including a lower rear leg having a lower end portion connected to the swivel frame at a position rearward from the position where the base end portion of the front leg is connected to the swivel frame. The lower hind legs extend upward from the second lower end toward the second upper end, and the upper hind legs extend upward from the first lower end toward the first upper end, and the upper hind legs extend upward. A working state in which the front leg extends diagonally forward and downward from the tip end portion toward the base end portion, and the first lower end portion of the upper rear leg is located on the front side of the first upper end portion, and the lower rear leg is located. The upper hind legs and the lower hind legs are folded and laid down so that the second upper end portion is located on the front side of the second lower end portion, and the front legs are placed on the laid down upper hind legs. It is configured to be switchable to a stored state in which the gantry is laid down so as to extend rearward from the base end portion to the tip end portion, and the gantry is held in the stored state when the gantry is in the stored state. The swivel frame includes a connecting member for connecting the tip end portion of the front leg to the swivel frame, and the swivel frame has a frame-coupled portion at the rear end portion of the upper rear leg and the lower rear leg. One of them has a rear leg bonded portion, and the connecting member is attached to the tip portion of the front leg so as to be rotatable around an axis extending in the left-right direction in the longitudinal direction of the connecting member. A first connecting end portion which is one end portion, a second connecting end portion on the opposite side thereof, and a connecting member connecting portion provided at the second connecting end portion, and the gantry is in the retracted state. When the connecting member is connected to the frame-coupled portion so that the tip end portion of the front leg and the rear end portion of the swivel frame are connected to each other, the gantry is in the working state. The connecting member is held in a posture extending downward along the upper hind legs from the first connecting end portion, and the first connecting member of the connecting member is held. The length from the first connecting end to the second connecting end, which is coupled to the hind leg coupled portion so that rotation with the connecting end as a fulcrum is restricted. As a result, the first length when the connecting member connecting portion is coupled to the frame coupled portion and the first length when the connecting member connecting portion is larger than the first length and is coupled to the hind leg coupled portion. It is configured so that it can have a length of 2.

In this construction machine, when connecting the tip of the front leg of the gantry to the swivel frame in order to hold the gantry in the retracted state, the connecting member is set to a relatively small first length and the connecting member connecting portion is connected to the frame. The tip of the front leg can be connected to the rear end of the swivel frame by the connecting member having a small length, and when the gantry is in the working state, the connecting member is made longer than the first length. The connecting member coupling portion can be coupled to the hind leg coupling portion so as to have a large second length and the rotation of the connecting member with the first connecting end portion as a fulcrum is restricted. Therefore, when the gantry is stored and the tip of the front leg of the gantry is connected to the rear end of the swivel frame by the connecting member, the gantry is upward as compared with the case where such a connection is performed by the connecting member having a large length. The tip of the front leg can be well constrained to the swivel frame against the force component of. Further, when the height of the gantry in the working state is increased, it is possible to prevent the position of the connecting member connecting portion from being raised accordingly, and the work of connecting the connecting member connecting portion to the hind leg joint portion. You can prevent the position where you do Therefore, in this construction machine, the gantry in the retracted state can be prevented from being lifted by the connecting member due to the vertical vibration and shaking during transportation of the upper swing body, and the gantry can be kept in the retracted state in a good working state. Even when the height of the gantry is increased, the connecting member joint is joined to the hind legs of the gantry in order to prevent the connecting member from colliding with the upper hind legs or the lower hind legs due to the rotation of the connecting member. It is possible to make it easy for the operator to perform the work of joining the parts.

In the construction machine, the connecting member is configured to be stretchable between the first length and the second length, and when the connecting member contracts to the first length, the connecting member is stretched. A contracted state holding portion for holding the connecting member to the first length, and an extended state holding portion for holding the connecting member to the second length when the connecting member is extended to the second length. It is preferable to further have a portion.

According to this configuration, when the tip end portion of the front leg of the retracted gantry is connected to the rear end portion of the swivel frame by the connecting member, the connecting member contracted to the first length is brought into contact with the contracted state holding portion. It can be held at a length of 1, and it is possible to prevent a decrease in the effect of suppressing the lifting of the gantry in the stored state caused by the extension of the connecting member from the first length. Further, when the gantry is in the working state, the connecting member extended to the second length is held to the second length by the extended state holding portion, and then the connecting member connecting portion of the connecting member is held by the rear leg. It can be bonded to the bonded portion. Therefore, the hind leg joint portion is like, for example, a receiving portion that receives the connecting member joint portion from below, and can be easily connected by simply placing the connecting member joint portion on the hind leg joint portion. However, even if the connecting member joint is easily disengaged from the hind leg joint when the connecting member is displaced upward, the connecting member can be held at the second length as described above, so that the connecting member is above the connecting member joint. It is possible to prevent the displacement to the rear leg, and prevent the connecting member joint from coming off from the hind leg joint.

As a specific configuration when the connecting member can be expanded and contracted between the first length and the second length, the connecting member includes an upper connecting member provided with the first connecting end portion and the second connecting member. From the first position and the first connecting end portion, which is a lower connecting member provided with a connecting end portion and the length from the first connecting end portion to the second connecting end portion is the first length. It has a second position in which the length to the second connecting end portion is the second length and is engaged with the upper connecting member so as to be slidable in the longitudinal direction. It may be a thing.

In this case, the contracted state holding portion has a first restraining portion for restraining the movement of the lower connecting member toward the second position when the lower connecting member is in the first position. Is preferable.

According to this configuration, the first restraining portion restrains the movement of the lower connecting member from the first position to the second position side when the lower connecting member is arranged at the first position, and the connecting member. Can be prevented from extending from the first length.

Further, the extended state holding portion has a second restraining portion for restraining the movement of the lower connecting member toward the first position when the lower connecting member is in the second position. Is preferable.

According to this configuration, the second restraining portion restrains the movement of the lower connecting member from the second position to the first position side when the lower connecting member is arranged at the second position, and the connecting member. Can be prevented from contracting from the second length.

In the construction machine, the upper swivel body further includes a counterweight attached to the rear end portion of the swivel frame so as to cover the frame-coupled portion and detachable from the rear end portion of the swivel frame. When the gantry is in the retracted state with the counterweight attached to the rear end of the swivel frame, the connecting member causes the tip of the front leg to become the counterweight. It is preferable to further have a counterweight coupling portion that couples to the counterweight so as to be linked.

According to this configuration, a counterweight is attached to the rear end of the swivel frame, and the counterweight covers the frame-coupled portion, so that the connecting member coupling portion cannot be coupled to the frame-coupled portion. Even so, the counterweight coupling portion of the connecting member can be coupled to the counterweight, and the tip of the front leg of the gantry in the retracted state can be connected to the counterweight by the connecting member, and the gantry is held in the retracted state. Can be done. When the counterweight is removed from the rear end of the swivel frame, the connecting member coupling portion is coupled to the frame-coupled portion, and the tip portion of the front leg of the gantry stored by the connecting member is rearward of the swivel frame. It can be connected to the end and the gantry can be held in the retracted state. Therefore, in this configuration, the gantry can be held in the retracted state by the connecting member regardless of whether the counterweight is attached to or removed from the rear end of the swivel frame.

As described above, according to the present invention, it is possible to prevent the gantry in the retracted state from rising by the connecting member, and the gantry can be held in the retracted state satisfactorily, and the height of the gantry becomes large. Even if the gantry is in the working state, the operator can easily connect the connecting member joint to the hind leg joint of the gantry in order to prevent the connecting member from colliding with the upper hind legs or the lower hind legs. Can provide construction machinery that can be done.

It is the figure which looked at the whole of the crawler crane as a construction machine by one Embodiment of this invention from the right side. It is a schematic side view of a crawler crane when a gantry is in a working state. It is a schematic side view of the crawler crane in the state where the gantry is in the process of transitioning from the working state to the retracted state. It is a schematic side view of a crawler crane in a state where the gantry is in the retracted state, but the connecting member hangs down from the tip of the gantry and the gantry is not connected to the swivel frame. It is a schematic side view of a crawler crane in a state where a gantry is in a working state and a connecting member connects the gantry to a swivel frame. It is a front view of the connecting member in a contracted state having a first length. It is a front view of the connecting member in an extended state having a second length. It is a schematic side view of the crawler crane as a construction machine according to the modification of this invention, and shows the state when the gantry is in the retracted state.

An embodiment of the present invention will be described with reference to FIGS. 1 to 7.

The present invention can be applied to gantry of various construction machines such as cranes and pile drivers. The crane includes all types of mobile cranes including crawler cranes and stationary cranes. The construction machine according to one embodiment of the present invention described below is the crawler crane 1 shown in FIG.

As shown in FIG. 1, the crawler crane 1 includes a crawler-type self-propellable lower traveling body 2, an upper rotating body 3 rotatably mounted on the lower traveling body 2, and a boom 5 which is a work attachment. And. The lower traveling body 2 is an example of the lower main body in the present invention.

The upper swivel body 3 has a swivel frame 4 as a base. The turning frame 4 is mounted on the lower traveling body 2 so as to be able to turn around the vertical axis. The boom 5 is attached to the front portion of the swivel frame 4 so as to be undulating with respect to the swivel frame 4. Further, the upper swivel body 3 is attached to a cab 6 (driver's cab) arranged on the front portion of the swivel frame 4, a gantry 7 installed on the swivel frame 4, and a rear end portion of the swivel frame 4. The counterweight 8 and the like are further included.

The front, rear, left, and right in the following description are defined with reference to the turning frame 4 that turns with respect to the lower traveling body 2. As shown in FIG. 1, the direction in which the front leg 32, which will be described later, of the gantry 7 falls down is the rear direction, and the opposite direction is the front direction. The left and right sides are determined based on the front according to the definition.

The crawler crane 1 further includes a boom guy line 9, an upper spreader 10, a boom undulating rope 11, a lower spreader 22, and a boom undulating drum 12. The boom guy line 9 has a first end fixed to the tip of the boom 5 and a second end connected to the upper spreader 10 on the side opposite to the first end. The gantry 7 has a shape including a top, and a lower spreader 22 is provided on the top. The boom undulating rope 11 is wound between the upper spreader 10 and the lower spreader 22. The boom undulating rope 11 has a base end fixed to the gantry 7, and a portion on the tip side of the base end is wound around the boom undulating drum 12. The boom undulating drum 12 is arranged at the rear of the swivel frame 4, and rotates so as to extend and wind the boom undulating rope 11 to increase or decrease the distance between the lower spreader 22 and the upper spreader 10. Raise and undulate the boom 5.

A boom point sheave 13, an idler sheave 14, and an auxiliary sheave 15 are rotatably provided at the tip of the boom 5. The main hook 17 is hung from the boom point sheave 13 via the main hoisting rope 16, and the auxiliary hook 19 is hung from the auxiliary sheave 15 via the auxiliary hoisting rope 18.

The main winding drum 20, the auxiliary winding drum 21, and the boom undulating drum 12 are arranged on the swivel frame 4 so as to be arranged from the front side in this order. Each of the drums 20, 21 and 12 has a drum rotation shaft, and is attached to the swivel frame 4 in a horizontal posture in which the drum rotation shaft extends in the left-right direction.

The main hoisting rope 16 has a tip fixed to the boom 5, and the portion of the main hoisting rope 16 on the base end side of the tip is supported by the boom point sheave 13 and the idler sheave 14 and the main hoisting rope 16. It is wound around the drum 20. The rotation of the main winding drum 20 causes the main hook 25 to be wound or unwound via the main hoisting rope 16.

The auxiliary hoisting rope 18 has a tip fixed to the auxiliary hook 19, and a portion of the auxiliary hoisting rope 18 on the base end side of the tip is supported by the auxiliary sheave 15 and the auxiliary winding drum 21. Wrapped around. By the rotation of the auxiliary winding drum 21, the auxiliary hook 19 is wound or unwound via the auxiliary winding rope 18.

The gantry 7 supports the lower spreader 22. The gantry 7 includes a pair of left and right front legs 32 and a pair of left and right rear legs 34 (see FIG. 2).

Each of the pair of front legs 32 has a base end portion 32a connected to the swivel frame 4 so as to be rotatable around an axis extending in the left-right direction of the upper swivel body 3 so that the front legs 32 can undulate, and the opposite side thereof. It has a tip portion 32b, which is a movable end portion of the above. In the present embodiment, the base end portion 32a of the front leg 32 is rotatably connected to the swivel frame 4 around a support shaft 33 made of a pin or the like, whereby the front leg 32 is supported by the swivel frame 4. The tip end portion 32b is one end portion in the longitudinal direction of the front leg 32 facing upward in the working state, and the base end portion 32a is the end portion of the front leg 32 on the opposite side to the tip end portion 32b.

The pair of rear legs 34 are arranged relative to the pair of front legs 32 in the working state. Each of the pair of hind legs 34 has an upper hind leg 36 and a lower hind leg 38.

The upper rear leg 36 has a first upper end portion 36a which is one end portion in the longitudinal direction of the upper rear leg 36 facing upward in the working state, and a first lower end portion 36b which is an end portion on the opposite side thereof. The first upper end portion 36a of the upper rear leg 36 is connected to the tip end portion 32b of the front leg 32 so as to be rotatable around an axis extending in the left-right direction. In the present embodiment, the first upper end portion 36a of the upper rear leg 36 is rotatably connected to the tip end portion 32b of the front leg 32 around a support shaft 39 made of a pin or the like.

The lower rear leg 38 has a second upper end portion 38a which is an end portion in the longitudinal direction of the lower rear leg 38 facing upward in the working state, and a second lower end portion 38b which is an end portion on the opposite side thereof. The second upper end portion 38a of the lower rear leg 38 is connected to the first lower end portion 36b of the upper rear leg 36 so as to be rotatable around an axis extending in the left-right direction. Further, the second lower end portion 38b of the lower rear leg 38 can rotate about an axis extending in the left-right direction at a position rearward from the position where the base end portion 32a of the front leg 32 is connected to the swivel frame 4. It is connected to the swivel frame 4 so as to be. In the present embodiment, the second upper end portion 38a of the lower rear leg 38 is connected to the first lower end portion 36b of the upper rear leg 36 via two connecting pins 40 and 41 arranged one above the other. The second lower end 38b of the lower rear leg 38 is rotatably connected to the swivel frame 4 around a support shaft 42 made of a pin or the like.

Of the two upper and lower connecting pins 40 and 41 that connect the upper rear leg 36 and the lower rear leg 38, the upper connecting pin 40 is a first pin insertion hole provided in the first lower end portion 36b of the upper rear leg 36. The first and second pin insertion holes are inserted into the second pin insertion holes provided in the second upper end 38a of the lower rear leg 38 in a state of being aligned with each other. The lower connecting pin 41 is formed in the third pin insertion hole provided in the first lower end portion 36b of the upper rear leg 36 and the elongated hole 38c provided in the second upper end portion 38a of the lower rear leg 38. The insertion hole and the elongated hole 38c are inserted so as to overlap each other.

The gantry 7 is configured to be switchable between the working state shown in FIG. 2 and the stored state shown in FIG.

In the working state shown in FIG. 2, the lower rear leg 38 extends upward from the second lower end 38b toward the second upper end 38a, and the upper rear leg 36 extends from the first lower end 36b to the first upper end 36a. The front leg 32 extends diagonally forward and downward from the tip end portion 32b toward the base end portion 32a. In the present embodiment, the upper hind legs 36 and the lower hind legs 38 extend along a substantially vertical line in this working state, but the work is performed in the longitudinal directions of the upper hind legs 36 and the lower hind legs 38, respectively. In the state, it does not necessarily have to exactly coincide with the vertical direction, and the longitudinal direction may be slightly tilted with respect to the vertical direction. Further, each of the longitudinal direction of the upper hind legs 36 and the longitudinal direction of the lower hind legs 38 does not necessarily have to be linear.

Further, in the retracted state shown in FIG. 4, the connecting pin 40 is removed from the upper rear leg 36 and the lower rear leg 38, and the first lower end portion 36b of the upper rear leg 36 is the first upper end portion 36a of the upper rear leg 36. The upper rear leg 36 and the lower rear leg 38 are folded so that the second upper end portion 38a of the lower rear leg 38 is located on the front side of the lower rear leg 38 and is located on the front side of the second lower end portion 38b of the lower rear leg 38. I'm lying down. Further, in this retracted state, the front leg 32 is laid down on the laid-down upper rear leg 36 so that the tip portion 32b thereof is located behind the base end portion 32a. Further, in this retracted state, the tip end portion 32b (top of the gantry 7) of the front leg 32 is located behind the rear end portion of the swivel frame 4.

The gantry 7 further includes a hydraulic cylinder 43 interposed between the lower portion of the front leg 32 and the swivel frame 4. The hydraulic cylinder 43 expands and contracts to rotate the front legs 32 of the gantry 7 around the support shaft 33. In the present embodiment, the front legs 32 rotate in the upright direction as the hydraulic cylinder 43 extends.

The gantry 7 further has a connecting shaft 44 that is erected between the tip portions 32b of the pair of left and right front legs 32 and extends in the left-right direction. A lower spreader 22 is attached to the connecting shaft 44.

The gantry 7 further has a pair of left and right connecting members 45. In the present embodiment, the pair of connecting members 45 swivel each of the tip portions 32b of the pair of front legs 32 so as to hold the gantry 7 in the retracted state when the gantry 7 is in the retracted state. It is connected to. The connecting member 45 may be provided only on either the left or right side.

Each of the pair of connecting members 45 is a first end portion in the longitudinal direction of the connecting member 45 attached to the tip end portion 32b of the corresponding front leg 32 so as to be rotatable about an axis extending in the left-right direction. It has one connecting end portion 45a, a second connecting end portion 45b which is an end portion of the connecting member 45 on the opposite side thereof, and a coupling pin 64 as a connecting member coupling portion provided on the second connecting end portion 45b. .. Further, each of the pair of connecting members 45 has a rod-shaped upper connecting member 46 having the first connecting end portion 45a and a rod-shaped lower connecting member 48 having the second connecting end portion 45b. ..

The upper connecting member 46 is provided on a pair of long plate portions 52 arranged at intervals in the left-right direction and at the end edges of the pair of plate portions 52 so as to straddle one end edge in the width direction. A side plate 54a that is attached and extends in the longitudinal direction of the plate portion 52 and a side plate 54a that is attached to the other end edges of the pair of plate portions 52 in the width direction so as to straddle each other and in the longitudinal direction of the plate portion 52. It has a side plate 54b extending to (see FIG. 6).

One end of the pair of plate portions 52 in the longitudinal direction is the first connecting end portion 45a. A pin insertion hole 55 is formed in the first connecting end portion 45a, and the first connecting end portion 45a can rotate around a pin 56 (see FIG. 2) inserted through the pin insertion hole 55. It is connected to the tip end portion 32b of the front leg 32 so as to be. Further, the portion where the first connecting end portion 45a is connected to the tip portion 32b of the front leg 32 is located on the rear side of the portion where the first upper end portion 36a of the upper rear leg 36 is connected to the tip portion 32b of the front leg 32. positioned. By connecting the first connecting end portion 45a to the tip end portion 32b of the front leg 32 as described above, the connecting member 45 can rotate around the first connecting end portion 45a as a fulcrum, that is, rotate around the pin 56. It is movable.

Further, the upper connecting member 46 has an internal space surrounded by the pair of plate portions 52 and the side plates 54a and 54b. This internal space is open at the end of the upper connecting member 46 opposite to the first connecting end 45a in the longitudinal direction. Further, in the side plates 54a and 54b, pin insertion holes 60 (see FIG. 6) are formed in the vicinity of the opposite ends thereof, respectively.

The lower connecting member 48 is made of an elongated plate body as shown in FIG. One end of the lower connecting member 48 in the longitudinal direction is the second connecting end 45b. A pin insertion hole 62 is formed in the second connecting end portion 45b, and the coupling pin 64 is inserted through the pin insertion hole 62.

The lower connecting member 48 is inserted into the internal space of the upper connecting member 46 from the end opposite to the second connecting end 45b through the opening of the opposite end of the upper connecting member 46. .. As a result, the lower connecting member 48 is engaged with the upper connecting member 46 so as to be slidable in the longitudinal direction thereof. With this configuration, the connecting member 45 can be expanded and contracted, and the connecting pin 64 has the length from the first connecting end portion 45a to the second connecting end portion 45b of the swivel frame 4 as described later. It takes a first length when it is coupled to the coupling hole 4a and a second length when the coupling pin 64 is larger than the first length and is coupled to the hind leg coupling portion 72 as described later. I'm getting it. The first length is the length of the connecting member 45 in a state where the lower connecting member 48 retracts into the upper connecting member 46. The second length is the length of the connecting member 45 in a state where the lower connecting member 48 is advanced from the upper connecting member 46.

The lower connecting member 48 has a first position fixing hole 66 provided at a position slightly closer to the end opposite to the second connecting end 45b, and a second connecting member 48 provided near the opposite end. It has a position fixing hole 68. In the first position fixing hole 66, the length of the lower connecting member 48 from the first connecting end 45a to the second connecting end 45b of the connecting member 45 with respect to the upper connecting member 46 is the first length. It is arranged so as to coincide with the pin insertion hole 60 when it is arranged at the first position (entry / exit position). In the second position fixing hole 68, the length of the lower connecting member 48 from the first connecting end 45a to the second connecting end 45b of the connecting member 45 with respect to the upper connecting member 46 is the second length. It is arranged so as to coincide with the pin insertion hole 60 when it is arranged at the second position (advanced position).

The connecting member 45 further has a position restraining pin 70, and when the lower connecting member 48 is in the first position, the position restraining pin 70 is the pin insertion hole 60 of the upper connecting member 46 and the lower connecting member. By being inserted into the first position fixing hole 66 of 48, the lower connecting member 48 is constrained to the first position with respect to the upper connecting member 46. Further, when the lower connecting member 48 is in the second position, the position restraining pin 70 is inserted into the pin insertion hole 60 of the upper connecting member 46 and the second position fixing hole 68 of the lower connecting member 48. The lower connecting member 48 is constrained to the second position with respect to the upper connecting member 46.

That is, the position restraining pin 70, the pin insertion hole 60, and the first position fixing hole 66 restrain the movement of the lower connecting member 48 toward the second position when the lower connecting member 48 is in the first position. This is an example of the first restraint portion of the present invention for holding the connecting member 45 in the first length when the connecting member 45 contracts to the first length. This is an example of a holding unit. Further, the position restraining pin 70, the pin insertion hole 60, and the second position fixing hole 68 restrain the movement of the lower connecting member 48 toward the first position when the lower connecting member 48 is in the second position. This is an example of the second restraint portion of the present invention for holding the connecting member 45 in the second length when the connecting member 45 is extended to the second length. This is an example of a holding unit.

As shown in FIG. 5, the second connecting end 45b is connected so that the tip 32b of the front leg 32 and the rear end of the swivel frame 4 are connected by the connecting member 45 when the gantry 7 is in the retracted state. It is coupled to the rear end of the swivel frame 4. Specifically, the swivel frame 4 has a coupling hole 4a (see FIG. 4) as a frame-coupled portion at its rear end, and the connecting member 45 has a first connecting end 45a in the retracted state of the gantry 7. The pin insertion hole 62 of the second connecting end 45b and the coupling hole 4a coincide with each other when rotating around the fulcrum to form a predetermined angle with respect to the swivel frame 4. By inserting the coupling pin 64 into the pin insertion hole 62 and the coupling hole 4a in the same state, the second connecting end portion 45b and the rear end portion of the swivel frame 4 are coupled. Then, by this connection, the relative positional relationship between the front leg 32, the upper rear leg 36, the lower rear leg 38, and the connecting member 45 is fixed, and the gantry 7 is held in the retracted state.

On the other hand, when the coupling pin 64 is pulled out from the pin insertion hole 62 and the coupling hole 4a, the second connecting end portion 45b can be separated from the rear end portion of the swivel frame 4, and the gantry 7 is moved from the retracted state to the working state. It can be migrated. However, since the connecting member 45 can rotate about the pin 56 attached to the first connecting end portion 45a, when the gantry 7 is in the working state, the connecting member 45 shakes and is rearward. It may collide with the legs 36 and the like, which may cause damage to the paint on the upper rear legs 36 and the connecting member 45 and the generation of collision noise.

In order to prevent such swinging (rotation) of the connecting member 45, the upper rear leg 36 further has a rear leg coupled portion 72 to which the coupling pin 64 is coupled in the working state of the gantry 7.

The rear leg joined portion 72 has a plate shape that protrudes rearward from the first lower end portion 36b of the upper rear leg 36 in the working state, and the connecting member 45 having the second length in the working state. It is arranged at a position corresponding to the coupling pin 64. The hind leg coupled portion 72 has a semicircular engaging groove 72a that can engage with the coupling pin 64. In the working state of the gantry 7, the coupling pin 64 of the connecting member 45 is fitted into the engaging groove 72a, so that the coupling pin 64 is coupled to the hind leg coupling portion 72, whereby the connecting member 45 is the first. The rotation (swing) of the connecting member 45 about the pin 56 attached to the first connecting end 45a while being held in a posture extending downward along the upper rear leg 36 from the connecting end 45a is restrained. It is supposed to be done.

In the working state of the gantry 7, the height position of the rear leg bonded portion 72 and the height position of the coupling pin 64 in a posture in which the connecting member 45 of the second length extends downward from the first connecting end portion 45a. Is within reach of the operator standing on the swivel frame 4 and their hind leg coupling portions 72 and coupling pins 64.

Further, as shown in FIG. 3, the coupling state of the engaging groove 72a of the rear leg coupled portion 72 and the coupling pin 64 is such that the lower rear leg 38 and the upper rear leg 36 are used to switch the gantry 7 from the working state to the retracted state. It is released by the operation of folding and, in particular, by rotating the upper rear leg 36 forward with respect to the support shaft 39.

In the crawler crane 1 according to the present embodiment configured as described above, the operation when the gantry 7 is switched from the retracted state to the working state and the operation when switching from the working state to the retracted state will be described.

First, in the retracted state of the gantry 7, as shown in FIG. 5, the tip end portion 32b of the fallen front leg 32 and the rear end portion of the swivel frame 4 are connected by the connecting member 45 having the contracted first length. ing. When switching from this stored state to the working state, the pin insertion hole 62 of the second connecting end 45b of the connecting member 45 and the connecting pin 64 inserted into the connecting hole 4a of the swivel frame 4 are pulled out from these holes, and the connecting member The connection between the second connecting end portion 45b of 45 and the rear end portion of the swivel frame 4 is released. As a result, the connecting member 45 is rotated around the first connecting end portion 45 as a fulcrum and hangs down from the tip end portion 32b of the front leg 32 as shown in FIG.

After that, the hydraulic cylinder 43 is extended to slightly erect the front leg 32. In that state, an operator standing on the ground pulls out the position restraint pin 70 (see FIG. 6) inserted into the pin insertion hole 60 and the first position fixing hole 66 of the connecting member 45 from those holes, and the lower connecting member. 48 is advanced downward from the upper connecting member 46, and the second position fixing hole 68 of the lower connecting member 48 is arranged at the second position corresponding to the pin insertion hole 60 of the upper connecting member 46. In that state, the operator inserts the position restraint pin 70 into the pin insertion hole 60 of the upper connecting member 46 and the second position fixing hole 68 of the lower connecting member 48 as shown in FIG. As a result, the lower connecting member 48 is constrained to the second position with respect to the upper connecting member 46, and the connecting member 45 is held to a second length larger than the first length. That is, the connecting member 45 is held in the extended state.

After that, the front leg 32 is further erected by further extending the hydraulic cylinder 43. As a result, the lower hind legs 38 and the upper hind legs 36, which were folded and laid down in the retracted state, rise up so that the angle between them increases as shown in FIG. 3, and the upper hind legs 36 and the connecting member are connected to each other. The angle between the connecting member 45 and the second connecting end portion 45b of the connecting member 45 becomes smaller, and the second connecting end portion 45b approaches the hind leg coupled portion 72. Then, as shown in FIG. 2, the hydraulic cylinder 43 raises the front legs 32 until the lower rear legs 38 and the upper rear legs 36 are in a posture in which they extend continuously in the substantially vertical direction, and puts the gantry 7 into a working state. In this state, the operator stands on the swivel frame 4 so that the position of the pin insertion hole 62 of the second connecting end 45 of the connecting member 45 matches the engaging groove 72a of the rear leg coupled portion 72. The swing position (rotation position) of the 45 is adjusted, the coupling pin 64 is inserted into the pin insertion hole 62, and the coupling pin 64 is fitted into the engaging groove 72a of the rear leg coupling portion 72. As a result, the connecting member 45 is restrained so as not to shake.

Next, when the gantry 7 is switched from the working state to the retracted state, the hydraulic cylinder 43 is contracted so that the front leg 32 is tilted backward and the upper rear leg 36 and the lower rear leg 38 are folded. At this time, the upper rear leg 36 rotates forward about the support shaft 39, and the coupling pin 64 fitted in the engaging groove 72a automatically rotates with the forward rotation of the upper rear leg 36. It disengages from the engaging groove 72a.

After that, the front leg 32 is tilted to a position where the second connecting end portion 45b of the connecting member 45 approaches the ground, and the lodging of the front leg 32 is temporarily stopped at that position. Then, on the ground, the operator pulls out the position restraint pin 70 (see FIG. 7) inserted into the pin insertion hole 60 and the second position fixing hole 68 of the connecting member 45 from those holes, and pulls out the lower connecting member 48. It is pulled up and retracted into the upper connecting member 46, and the lower connecting member 48 is arranged at the first position where the first position fixing hole 66 of the lower connecting member 48 coincides with the pin insertion hole 60 of the upper connecting member 46. To do. In that state, the operator inserts the position restraint pin 70 into the pin insertion hole 60 of the upper connecting member 46 and the first position fixing hole 66 of the lower connecting member 48 as shown in FIG. As a result, the lower connecting member 48 is constrained to the first position with respect to the upper connecting member 46, and the connecting member 45 is held to a first length smaller than the second length. That is, the connecting member 45 is held in the contracted state.

After that, the front leg 32 is further tilted by further contracting the hydraulic cylinder 43, and the gantry 7 is brought into the retracted state as shown in FIG. Then, in this state, the operator pulls out the coupling pin 64 from the pin insertion hole 62 of the second connecting end portion 45b of the connecting member 45, and rotates the connecting member 45 forward with the first connecting end portion 45a as a fulcrum. Then, the connecting member 45 is arranged at a position where the pin insertion hole 62 coincides with the coupling hole 4a of the swivel frame 4. In that state, the operator inserts the coupling pin 64 into the pin insertion hole 62 of the second connecting end 45b and the coupling hole 4a of the swivel frame 4, thereby inserting the second connecting end 45b into the rear end of the swivel frame 4. Join the part. As a result, the tip end portion 32b of the front leg 32 and the rear end portion of the swivel frame 4 are connected by the connecting member 45 so as to prevent the gantry 7 in the retracted state from rising, and the gantry 7 is held in the retracted state.

As described above, the operation of switching the gantry 7 from the stored state to the working state and the operation of switching from the working state to the stored state are performed.

In the present embodiment, when the tip portion 32b of the front leg 32 is connected to the swivel frame 4 in order to hold the gantry 7 in the retracted state, the connection is performed by the connecting member 45 having a relatively small first length. When the gantry 7 is in the working state, the connecting member 45 is set to a second length larger than the first length, and the connecting member 45 is rotated (swayed) with the first connecting end portion 45a as a fulcrum. The coupling pin 64 attached to the second connecting end portion 45b of the connecting member 45 can be coupled to the hind leg coupled portion 72 so that the motion) is restrained. Therefore, when the tip portion 32b of the front leg 32 is connected to the rear end portion of the swivel frame 4 by the connecting member 45 with the gantry 7 in the retracted state, the tip portion 32b of the front leg 32 opposes the component of the upward force. While the capacity of the connecting member 45 to be fastened to the swivel frame 4 can be sufficiently secured, the gantry 7 can be operated even when the height of the gantry 7 increases due to the increase in size of the crawler crane 1 as a construction machine. It is possible to prevent the position of the coupling pin 64 from being raised when the state is set, and to prevent the position where the coupling pin 64 is coupled to the hind leg coupling portion 72 from being raised. Therefore, in the present embodiment, the connecting member 45 can prevent the gantry 7 in the retracted state from rising due to vertical vibration and shaking during transportation of the upper swing body 3, and the gantry 7 can be held in the retracted state satisfactorily. At the same time, even when the height of the gantry 7 is increased, it is attached to the second connecting end 45b in order to prevent the connecting member 45 from colliding with the upper hind legs 36 and the like when the gantry 7 is put into the working state. The work of connecting the coupling pin 64 to the hind leg coupling portion 72 can be easily performed by the operator.

Further, in the present embodiment, the connecting member 45 restrains the movement of the lower connecting member 48 toward the second position (advancing position) when the lower connecting member 48 is in the first position (retracting position). It has a pin insertion hole 60, a first position fixing hole 66, and a position restraint pin 70 for the purpose. Therefore, when the lower connecting member 48 is arranged at the first position with respect to the upper connecting member 46 and the connecting member 45 is contracted to the first length, the lower connecting member 48 toward the second position The movement can be restrained by the position restraint pin 70 inserted through the pin insertion hole 60 and the first position fixing hole 66, and the connecting member 45 can be held by the first length. Therefore, when the tip end portion 32b of the front leg 32 of the gantry 7 in the retracted state is connected to the rear end portion of the swivel frame 4 by the connecting member 45 contracted to the first length, the connecting member 45 becomes the first. It is possible to prevent a decrease in the effect of suppressing the floating of the gantry 7 in the stored state caused by extending from the length.

Further, in the present embodiment, the connecting member 45 restrains the movement of the lower connecting member 48 toward the first position (retracting position) when the lower connecting member 48 is in the second position (advancing position). It has a pin insertion hole 60, a second position fixing hole 66, and a position restraint pin 70 for the purpose. Therefore, when the lower connecting member 48 is arranged at the second position with respect to the upper connecting member 46 and the connecting member 45 has the second length, the lower connecting member 48 moves toward the first position. The connecting member 45 can be held by the second length by being restrained by the position restraining pin 70 inserted through the pin insertion hole 60 and the second position fixing hole 68. Therefore, the rear leg joint portion 72 is like a receiving portion that receives the coupling pin 64 from below, and the coupling pin 64 can be easily coupled by simply placing the coupling pin 64 on the engagement groove 72a of the leg joint portion 72 thereafter. However, when the lower connecting member 48 is displaced upward and the coupling pin 64 is displaced upward, the coupling pin 64 is likely to come off from the engaging groove 72a of the rear leg coupling portion 72. However, since the connecting member 45 can be held to the second length as described above, the coupling pin 64 can be prevented from being displaced upward, and the coupling pin 64 can be prevented from being disengaged from the engaging groove 72a of the rear leg bonded portion 72. Can be stopped.

The construction machine according to the present invention is not necessarily limited to the above. For example, the following configuration can be adopted for the construction machine according to the present invention.

Even if the connecting member has a coupling that can be coupled to the counterweight when the gantry is in the retracted state, in addition to a coupling that can be coupled to the rear end of the swivel frame when the gantry is in the retracted state. Good. The configuration of the crawler crane 1 as a construction machine according to this modification is shown in FIG.

The counterweight 8 is attached to the rear end portion of the swivel frame 4 so as to cover the coupling hole 4a. The counterweight 8 is removable from the rear end of the swivel frame 4.

In the connecting member 45, when the gantry 7 is in the retracted state with the counterweight 8 attached to the rear end of the swivel frame 4, the tip 32b of the front leg 32 is connected to the counterweight 8 by the connecting member 45. As described above, it has a counterweight coupling unit 80 that couples to the counterweight 8.

The counterweight coupling portion 80 has a short plate shape. One end of the counterweight coupling portion 80 is pin-coupled to a position slightly closer to the first connecting end portion 45a than the second connecting end portion 45b of the connecting member 45. Therefore, if the pin for the coupling is removed, the counterweight coupling portion 80 can be separated from the connecting member 45, and the counterweight 8 is removed from the swivel frame 4 to connect the rear end portion of the swivel frame 4. When connecting the second connecting end portion 45b to the hole 4a with the coupling pin 64, the counterweight coupling portion 80 is removed from the connecting member 45. Further, a pin insertion hole (not shown) is formed at the other end of the counterweight coupling portion 80.

At the rear end of the counterweight 8, a recess recessed toward the front is formed. In this recess, a pair of joints (not shown) arranged so as to sandwich the other ends from both sides when the other end of the counterweight coupling portion 80 is inserted into the recess is provided. , Pin insertion holes are formed in each of the pair of joints. Then, by inserting a pin into the pin insertion hole of the pair of coupling portions and the pin insertion hole at the other end of the counterweight coupling portion 80, the counterweight coupling portion 80 is coupled to the counterweight 8. It has become.

According to this modification, the counterweight 8 is attached to the rear end portion of the swivel frame 4, and the second connecting end portion 45b of the connecting member 45 cannot be coupled to the coupling hole 4a of the swivel frame 4. Also, the counterweight coupling portion 80 of the connecting member 45 can be coupled to the counterweight 8 and the tip portion 32b of the front leg 32 of the gantry 7 in the retracted state can be connected to the counterweight 8 by the connecting member 45, and the gantry 7 can be stored. Can be kept in a state.

In this modification, when the counterweight 8 is removed from the rear end portion of the swivel frame 4, the second connecting end portion 45b of the connecting member 45 can be coupled to the coupling hole 4a via the coupling pin 64. Therefore, the coupling may be performed in the same manner as in the above embodiment. Therefore, in this modification, the connecting member 45 is used regardless of whether the counterweight 8 is attached to the rear end of the swivel frame 4 or the counterweight 8 is removed from the rear end. Therefore, the gantry 7 can be held in the stored state.

Further, the connecting member in the present invention is not necessarily limited to one that is configured to be expandable and contractible by moving the lower connecting member forward and backward with respect to the upper connecting member. For example, the connecting member may have the first length and the second length because the lower connecting member is foldable with respect to the upper connecting member.

Further, the second position fixing holes for fixing the lower connecting member to the second position with respect to the upper connecting member in order to hold the connecting member to the second length are mutually provided in the longitudinal direction of the lower connecting member. A plurality of them may be provided at different positions. According to this configuration, when the height position of the hind leg joined portion in the working state of the gantry varies depending on the height of the gantry, the second position fixing hole for inserting the position restraint pin can be selected. The length of the connecting member can be adjusted to an appropriate length for connecting the second connecting end portion to the rear leg bonded portion via the coupling pin, and the versatility of the connecting member can be enhanced.

Further, in the above-described embodiment, the pin insertion hole for inserting the position restraint pin is provided in the upper connecting member, and the first position fixing hole and the second position fixing hole are provided in the lower connecting member. A pin insertion hole for inserting the restraint pin may be provided in the lower connecting member, and a first position fixing hole and a second position fixing hole may be provided in the upper connecting member.

Further, the lower connecting member may be provided with a handle for the operator to grip when pulling the lower connecting member from the second position (advanced position) to the first position (retreat position). Further, the lower connecting member may be provided with an opening, a concave portion or a convex portion for the operator to handle when the lower connecting member is pulled up. According to these configurations, it is possible to easily pull up the lower connecting member.

Further, the connecting member may be provided with a driving device for expansion and contraction thereof. Specifically, for example, the connecting member may include a hydraulic cylinder, a pneumatic cylinder, or a hydraulic cylinder for sliding the lower connecting member with respect to the upper connecting member. Further, the connecting member may include an electric mechanism that slides the lower connecting member by using the power of the electric motor, a mechanism that slides the lower connecting member with a winch, a wire, and a pulley.

7 Gantry 32 Front leg 36 Upper rear leg 38 Lower rear leg 45 Connecting member 45a First connecting end 45b Second connecting end 72 Rear leg coupling 80 Counterweight coupling

Claims (6)

With the lower body
An upper swivel body having a swivel frame mounted on the lower body so as to be swivel,
A front leg having a base end portion connected to the swivel frame and a tip end portion on the opposite side thereof so as to be rotatable around an axis extending in the left-right direction of the upper swivel body, and an axial rotation extending in the left-right direction to the tip end portion. An upper hind leg having a first upper end portion connected so as to be rotatable and a first lower end portion on the opposite side thereof, and the first lower end portion that can rotate about an axis extending in the left-right direction. The second upper end portion and the second lower end portion on the opposite side of the second upper end portion connected so as to be connected to the swivel frame at a position rearward from the position where the base end portion of the front leg is connected to the swivel frame. A gantry including a lower hind leg having the same part, wherein the lower hind leg extends upward from the second lower end portion toward the second upper end portion, and the upper hind leg extends upward toward the second upper end portion, and the upper hind leg is the first lower end portion. The working state in which the front leg extends diagonally forward and downward from the tip to the base end, and the first lower end of the upper rear leg extends upward toward the first upper end portion. The upper hind legs and the lower hind legs are folded and laid down so that the second upper end of the lower hind legs is located on the front side of the first upper end and the second upper end of the lower hind legs is located on the front side of the second lower end. In addition, the front leg is configured to be switchable to a retracted state in which the front leg is laid down so as to extend rearward from the base end portion toward the tip end portion on the laid-down upper rear leg.
A connecting member for connecting the tip of the front leg to the swivel frame so as to hold the gantry in the retracted state when the gantry is in the retracted state is provided.
The swivel frame has a frame-coupled portion at its rear end.
Either the upper hind leg or the lower hind leg has a hind leg joint.
The connecting member includes a first connecting end portion, which is one end portion in the longitudinal direction of the connecting member, which is attached to the tip end portion of the front leg so as to be rotatable around an axis extending in the left-right direction. A second connecting end portion on the opposite side and a connecting member connecting portion provided at the second connecting end portion, and when the gantry is in the retracted state, the connecting member causes the tip end portion of the front leg. And the rear end of the swivel frame are coupled to the frame to be coupled so that the connecting member is connected from the first connecting end to the upper portion when the gantry is in the working state. It is held in a posture extending downward along the hind legs and is coupled to the hind legs to be joined so as to restrain the rotation of the connecting member with the first connecting end as a fulcrum. The length from the first connecting end portion to the second connecting end portion is larger than the first length when the connecting member connecting portion is coupled to the frame connected portion and the first length thereof. A construction machine that is large and is configured to have a second length when the connecting member joint is joined to the hind leg joint. The connecting member is configured to be stretchable between the first length and the second length, and when the connecting member contracts to the first length, the connecting member is contracted to the first length. It further has a contracted state holding portion for holding the connecting member and an extended state holding portion for holding the connecting member to the second length when the connecting member is extended to the second length. , The construction machine according to claim 1. The connecting member is an upper connecting member provided with the first connecting end portion and a lower connecting member provided with the second connecting end portion, and the first connecting end portion to the second connecting end portion. The upper side between the first position where the length up to is the first length and the second position where the length from the first connecting end to the second connecting end is the second length. The construction machine according to claim 2, further comprising one that is engaged with a connecting member so as to be slidable in the longitudinal direction. 3. The contracted state holding portion has a first restraining portion for restraining the movement of the lower connecting member toward the second position when the lower connecting member is in the first position. Described construction machinery. 3. The extension state holding portion has a second restraining portion for restraining the movement of the lower connecting member toward the first position when the lower connecting member is in the second position, according to claim 3 or The construction machine according to 4. The upper swivel body further includes a counterweight attached to the rear end portion of the swivel frame so as to cover the frame-coupled portion and detachable from the rear end portion of the swivel frame.
In the connecting member, when the gantry is in the retracted state with the counterweight attached to the rear end of the swivel frame, the connecting member connects the tip of the front leg to the counterweight. The construction machine according to any one of claims 1 to 5, further comprising a counterweight coupling portion that is coupled to the counterweight as described above.

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