JP6250382B2 - Boom desorption structure - Google Patents

Description

  The present invention relates to a boom detaching structure in which a base end portion of a boom is coupled to a revolving upper body of a construction machine by a boom foot pin, and the boom foot pin can be easily removed when the boom is removed from the upper revolving body. The present invention relates to a boom detaching structure that can be used.

  In construction machines such as a crawler crane and an earth drill, the upper swing body is mounted so as to be able to swing with respect to the lower traveling body, and the boom is attached to the upper swing body so as to be raised and lowered. In the case of a large construction machine, in order to facilitate transportation and reduce the weight, the boom is removed (disassembled) from the upper swing body and transported to the site. Then, the work is performed by attaching the boom to the upper swing body at the site.

  Here, the connection between the boom and the upper swing body will be described in detail. A mounting bracket extending in the front-rear direction of the boom is provided on the front side of the upper swing body, and a boom foot extending in parallel with the mounting bracket is provided at the base end of the boom. The boom foot and the mounting bracket are respectively formed with insertion holes extending in the left-right direction orthogonal to the front-rear direction of the boom.

  In this boom attachment / detachment structure, the boom is attached to the upper swing body by inserting the boom foot pin through the insertion hole of the boom foot and the insertion hole of the mounting bracket. Further, the boom is removed from the upper swing body by removing the boom foot pin from the insertion hole of the boom foot and the insertion hole of the mounting bracket.

  Conventionally, when a boom is attached to an upper swing body, the boom is lifted by a crane rope so that the boom is horizontal. Then, the boom foot insertion hole is aligned with the mounting bracket insertion hole while the boom is lifted. Thereby, when the position of the insertion hole of the boom foot matches the position of the insertion hole of the mounting bracket, the boom foot pin is inserted into these insertion holes. However, if the boom is large and heavy, it is difficult to lift the boom so that it is horizontal while adjusting the center of gravity of the boom with the rope of the crane. For this reason, the work of positioning the insertion holes is not easy, and the work load and work time for inserting the boom foot pins are large.

  Therefore, Patent Document 1 below describes a boom detaching structure that can easily perform the alignment operation of the insertion hole. In this boom attachment / detachment structure, as shown in FIG. 11, two protrusions 139 are provided on the upper surface 138 b of the boom foot 138, and support pins 150 extending in the left-right direction of the boom (left-right direction in FIG. 11) It penetrates the pin hole 139a. And the pin receiving seat 115 which supports the both ends of the support pin 150 is provided in the upper surface of the two mounting brackets 114 which left | separated in the left-right direction, as shown in FIG.

  In this boom attachment / detachment structure 100, when the boom (boom foot 138) is attached to the upper swing body (each attachment bracket 114), if both ends of the support pin 150 are placed on each pin receiving seat 115, the insertion hole 138a of the boom foot 138 is formed. The position is adapted to the position of the insertion hole 114 a of each mounting bracket 114. Thereby, the alignment work of the insertion hole 138a and the insertion hole 114a can be easily performed, and the work load and work time for inserting the boom foot pin 140 can be reduced.

JP 2006-282287 A

  By the way, when removing a boom from an upper turning body, the operator of a crane must lift so that a boom may become horizontal, aligning the gravity center of a boom with the rope of a crane. However, if the boom is small and has a small weight, it is easy to grasp the center of gravity of the boom by the tension of the rope that suspends the boom, but if the boom is large and heavy, the center of gravity of the boom is not known. Without it, it is difficult to lift the boom horizontally.

  For this reason, the weight of the base end part of the boom acts on the boom foot pin via the boom foot, making it difficult to remove the boom foot pin. And if the tension of the rope that suspends the base end of the boom is insufficient, the base end of the boom falls when the boom foot pin is pulled out, and is provided on the upper swing body There is a risk of damaging the hose. On the other hand, even if the tension of the rope that suspends the base end portion of the boom is too great, when the boom foot pin is pulled out, the base end portion of the boom suddenly rises and there is a risk of a dangerous state. Thus, when removing the boom from the upper revolving structure, it is difficult to remove the boom foot pin, and even if the boom foot pin can be removed, the base end of the boom lifted by the crane greatly moves up and down. It was.

  Here, in the boom attachment / detachment structure 100 described in Patent Document 1, although it is considered to reduce the work time and work load for inserting the boom foot pin 140, the boom foot pin 140 is to be removed. No consideration is given to reducing the work time and work load. That is, in the boom attaching / detaching structure 100, after the boom foot pin 140 is inserted into the insertion holes 114a and 138a and the boom is attached to the upper swing body, the support pin 150 is provided so that the boom can be raised and lowered with respect to the upper swing body. The protrusion 139 is extracted from the pin hole 139a. Thereby, the weight of the base end portion of the boom greatly acts on the boom foot pin 140 via the boom foot 138. Therefore, when removing the boom from the upper swing body, it is difficult to remove the boom foot pin 140, and the same problem as described above occurs.

  Therefore, the present invention has been made to solve the above-described problems, and when removing the boom from the upper swing body, the boom foot pin can be easily removed, and when removing the boom foot pin, a crane is used. An object of the present invention is to provide a boom detaching structure that can suppress the vertical movement of the base end portion of the boom to be lifted.

  In the boom detaching structure according to the present invention, the mounting bracket provided on the upper swing body of the construction machine extends in the front-rear direction of the boom, and the boom foot provided at the base end portion of the boom extends in parallel with the mounting bracket. The mounting bracket and the boom foot are respectively formed with insertion holes extending in the left-right direction perpendicular to the front-rear direction of the boom, and the boom foot pin is inserted into the insertion hole of the boom foot and the insertion hole of the mounting bracket. In the boom attachment / detachment structure, the boom is attached to the upper swing body, and the boom foot pin is removed from the boom foot insertion hole and the mounting bracket insertion hole so that the boom is removed from the upper swing body. The upper swing body is fitted with a hydraulic cylinder whose tip can be expanded and contracted vertically. The boom foot insertion hole and the mounting bracket insertion hole are aligned with each other, and a downward block attached to the lower side of the boom foot and an upward attachment attached to the tip of the hydraulic cylinder. It is provided so that a block may be engaged.

  According to the boom attaching / detaching structure according to the present invention, when the boom is attached to the upper swing body, the tip end portion of the hydraulic cylinder is extended upward. And while hanging a boom with the rope of a crane, the downward block of a boom foot is engaged with the upward block of the front-end | tip part of a hydraulic cylinder. Thereby, the position of the insertion hole of the boom foot matches the position of the insertion hole of the mounting bracket. Thereafter, the boom can be attached to the upper swing body by inserting the boom foot pin into these insertion holes. In this way, the operation of positioning the insertion hole can be easily performed, and the work burden and work time for inserting the boom foot pin can be reduced. Then, after the boom is attached to the upper swing body, the tip of the hydraulic cylinder is contracted downward so that the boom foot does not interfere with the tip of the hydraulic cylinder when the boom is raised and lowered relative to the upper swing body.

  On the other hand, when removing the boom from the upper swing body, the tip of the hydraulic cylinder is extended upward, and the upper block of the tip of the hydraulic cylinder is engaged with the lower block of the boom foot. Thereby, the boom foot (base end portion of the boom) is supported by the hydraulic cylinder, and the base end portion of the boom is slightly lifted. As a result, the weight of the base end portion of the boom does not significantly act on the boom foot pin via the boom foot, and the boom foot pin can be easily pulled out.

  Then, when the crane operator lifts the boom with the rope of the crane, it is only necessary to move the base end of the boom toward the hydraulic cylinder so that the base end of the boom is slightly lowered from the tip end of the boom. Thereby, when a boom foot pin is extracted, the base end part of a boom does not rise rapidly. Further, since the boom foot is supported by the hydraulic cylinder, the base end portion of the boom does not fall. Thus, when the boom foot pin is pulled out, the vertical movement of the base end portion of the boom lifted by the crane can be suppressed.

Further, in the boom detaching structure according to the present invention, a concave recess is formed in one of the lower surface of the downward block and the upper surface of the upward block, and the lower surface of the downward block and the upper surface of the upward block On the other side, a convex part that fits into the concave part is preferably formed.
In this case, the state where the alignment of the insertion hole of the boom foot and the insertion hole of the mounting bracket is completed by the fitting of the convex part and the concave part, and the state where the support of the boom foot is completed by the hydraulic cylinder are surely grasped. Can do.

In the boom detaching structure according to the present invention, it is preferable that the concave portion is recessed in a conical shape with respect to the horizontal direction, and the convex portion protrudes in a conical shape with respect to the horizontal direction.
In this case, in the alignment of the insertion hole of the boom foot and the insertion hole of the mounting bracket, the conical convex part and the conical concave part are fitted together, so that all directions of the front and rear direction, the left and right direction, and the vertical direction Can be aligned at the same time.

Further, in the boom attachment / detachment structure according to the present invention, the concave portion is formed on the upper surface of the upward block, the convex portion is formed on the lower surface of the downward block, and the inclination angle of the convex portion with respect to the horizontal direction is The inclination angle of the concave portion with respect to the horizontal direction may be slightly larger.
In this case, by setting the inclination angle of the convex portion to be slightly larger than the inclination angle of the concave portion in advance, even if the inclination angle slightly deviates due to a manufacturing error or the like, Can be matched. For this reason, a convex part and a recessed part can be fitted in the correct position, without being influenced by manufacturing error etc.

Further, in the boom detaching structure according to the present invention, the downward block and the upward block are aligned so as to be engaged when the tip end portion of the hydraulic cylinder extends upward. good.
In this case, when engaging the downward block and the upward block, it is only necessary to extend the tip of the hydraulic cylinder to the uppermost position, and it is necessary to finely adjust the height position of the tip of the hydraulic cylinder. There is no. Therefore, the operation of the hydraulic cylinder when engaging the downward block and the upward block is very simple.

  According to the boom attachment / detachment structure of the present invention, when the boom is attached to the upper swing body, the work time and work load for inserting the boom foot pin can be reduced. Furthermore, since the vertical movement of the base end portion of the boom lifted by the crane can be suppressed when the boom foot pin is pulled out, the operation of removing the boom from the upper swing body can be performed safely. In addition, when removing the boom from the upper swing body, the crane operator does not need an advanced operation technique for finely adjusting the center of gravity of the boom with the rope while adjusting the center of gravity. Therefore, when removing the boom from the upper swing body, the work time and work load for removing the boom foot pin can be reduced.

It is the side view which showed the earth drill to which the boom detaching structure of this embodiment is applied. It is the side view which expanded the front side and telescopic boom of the upper revolving structure shown in FIG. FIG. 3 is a top view when FIG. 2 is viewed from above. It is a front view when it sees along the AA line of FIG. It is the top view to which the B section of Drawing 3 was expanded. It is the side view to which the C section of Drawing 2 was expanded. It is the side view to which the inner side boom foot and the downward block shown in FIG. 6 were expanded. FIG. 7 is an enlarged side view of the hydraulic cylinder and the upward block shown in FIG. 6. FIG. 7 is a cross-sectional view of the upward block and the downward block shown in FIG. 6. It is the perspective view which showed the upward block and downward block of deformation | transformation embodiment. It is the front view which showed the conventional boom removal | desorption structure. It is the perspective view which showed the support pin and pin receiving seat of FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments of a boom detaching structure according to the present invention will be described with reference to the drawings. FIG. 1 is a side view showing an earth drill 1 to which a boom detaching structure BD of the present embodiment is applied. Here, the left-right direction in FIG. 1 is the front-rear direction of the boom, and is simply referred to as “front-rear direction” below. Further, the direction orthogonal to the paper surface of FIG. 1 is the left-right direction of the boom, and is simply referred to as “left-right direction” below.

  The earth drill 1 performs excavation of a hole and discharge of excavated earth and sand, and as shown in FIG. 1, the upper swing body 10 is mounted so as to be swingable with respect to the lower traveling body 20. And the telescopic boom 30 is attached to the front side of the upper revolving structure 10 so that raising / lowering is possible. FIG. 1 shows a state where the telescopic boom 30 is tilted.

  The upper swing body 10 has a driver's cab 11 on the front right side (front side in FIG. 1), and has an equipment room 12 on the rear right side. Further, an engine room (not shown) that houses an engine and a hydraulic pump is provided on the left side of the upper swing body 10 (the back side in FIG. 1). A foldable gantry 13 is provided on the upper rear side of the upper swing body 10.

  The lower traveling body 20 can travel by a crawler 21 and supports the upper revolving body 10 by a bearing 22 so as to be able to swivel. Here, FIG. 2 is an enlarged side view of the front side of the upper-part turning body 10 and the telescopic boom 30 shown in FIG. FIG. 3 is a top view when FIG. 2 is viewed from above.

  As shown in FIGS. 2 and 3, the telescopic boom 30 has a telescopic structure that extends in the front-rear direction and can expand and contract in two stages. In the telescopic boom 30, three booms having a rectangular cross section are coaxially overlapped, and the thickest lower boom 31 in the order close to the upper swing body 10, the middle boom 32 having an intermediate thickness, It is composed of a thin upper boom 33.

  The middle boom 32 is inserted into the lower boom 31 and is slidable with respect to the lower boom 31. The upper boom 33 is inserted into the middle boom 32 and is slidable with respect to the middle boom 32. A first telescopic cylinder 41 (see FIG. 1) that slides the middle boom 32 relative to the lower boom 31 is provided inside the telescopic boom 30, and a second telescopic that slides the upper boom 33 relative to the middle boom 32. A cylinder 42 (see FIG. 1) is provided.

  A front frame 34 and a frame cylinder 35 are attached to the lower boom 31 for supporting a Keriba driving device (not shown). A pendant rope 36 for raising and lowering the telescopic boom 30 is attached to the front end of the middle boom 32. A top sheave 37 for winding a lifting rope is provided at the tip of the upper boom 33.

  In order to facilitate transport and reduce the weight of the earth drill 1, the upper swing body 10 and the telescopic boom 30 are attached and detached. That is, the telescopic boom 30 is removed (disassembled) from the upper swing body 10 and transported to the site. Then, the telescopic boom 30 is attached to the upper swing body 10 at the site, and the excavation of the pit and the excavated earth and sand are performed. Here, the boom detaching structure BD will be described in detail. 4 is a front view when viewed along line AA in FIG. 2, and FIG. 5 is an enlarged top view of a portion B in FIG.

  In the boom attachment / detachment structure BD, as shown in FIG. 5, a right side mounting bracket 14 </ b> R extending in the front-rear direction is provided on the front side and the right side of the upper swing body 10. The right mounting bracket 14R has an insertion hole 14a for inserting the boom foot pin 40R. Further, the base end portion 30 a of the telescopic boom 30 is formed with an upright portion 30 b that is an upright plane. An outer boom foot 38a and an inner boom foot 38b extending in parallel with the right mounting bracket 14R are provided on the right side of the standing portion 30b.

  As shown in FIG. 4, the outer boom foot 38a and the inner boom foot 38b sandwich the right mounting bracket 14R and have insertion holes 38a1 and 38b1 for inserting the boom foot pin 40R. The boom foot pin 40R is a pin having a diameter of about 90 mm, and rotatably attaches the outer boom foot 38a and the inner boom foot 38b to the right mounting bracket 14R.

  A guide portion 14x is formed on the upper side of the right mounting bracket 14R so as to protrude inward (left side in FIG. 4). Thereby, the inner boom foot 38b is guided to the inner surface of the guide portion 14x, and the outer boom foot 38a is guided to the outer surface of the right mounting bracket 14R. Thus, the position in the left-right direction of the right mounting bracket 14R is defined.

Similarly, as shown in FIG. 5, a left mounting bracket 14 </ b> L extending in the front-rear direction is provided on the front side and the left side of the upper swing body 10. The left mounting bracket 14L has an insertion hole 14b for inserting the boom foot pin 40L. An outer boom foot 39a and an inner boom foot 39b that extend in parallel with the left mounting bracket 14L are provided on the left side of the upright portion 30b.

  As shown in FIG. 4, the outer boom foot 39a and the inner boom foot 39b sandwich the left mounting bracket 14L and have insertion holes 39a1 and 39b1 for inserting the boom foot pin 40L. The boom foot pin 40L is a pin having a diameter of about 90 mm, and rotatably attaches the outer boom foot 39a and the inner boom foot 39b to the left mounting bracket 14L.

  A guide portion 14y is formed on the upper side of the left mounting bracket 14L so as to protrude toward the inside (the right side in FIG. 4). Thereby, the inner boom foot 39b is guided to the inner surface of the guide portion 14y, and the outer boom foot 39a is guided to the outer surface of the left mounting bracket 14L. Thus, the left-right position of the left mounting bracket 14L is defined.

  As shown in FIGS. 4 and 5, boom foot pin attaching / detaching devices 50 </ b> R and 50 </ b> L and a hydraulic drive device 60 are fixedly provided at the base end portion 30 a of the telescopic boom 30. The boom foot pin attaching / detaching device 50R inserts and removes the boom foot pin 40R into and from the insertion hole 38b1 of the inner boom foot 38b, the insertion hole 14a of the right mounting bracket 14R, and the insertion hole 38a1 of the outer boom foot 38a. Similarly, the boom foot pin attaching / detaching device 50L inserts and removes the boom foot pin 40L into and from the insertion hole 39b1 of the inner boom foot 39b, the insertion hole 14b of the left mounting bracket 14L, and the insertion hole 39a1 of the outer boom foot 39a. .

  These boom foot pin attaching / detaching devices 50R and 50L are configured to include hydraulic cylinders that extend and contract the cylinder rod in the left-right direction. The cylinder rod and the boom foot pins 40R, 40L are integrally connected. When operating the boom foot pin attaching / detaching devices 50R and 50L, the piping of the hydraulic drive device 60 is connected to the hydraulic cylinder. Thereby, pressure oil is supplied from the hydraulic drive device 60 to the hydraulic cylinder, and the cylinder rod expands and contracts in the left-right direction so that the boom foot pins 40R, 40L can be inserted and removed. In the following description, when both the right mounting bracket 14R and the left mounting bracket 14L are meant, they are simply referred to as “mounting brackets 14R, 14L”.

  Next, the operation of attaching the telescopic boom 30 to the upper swing body 10 will be described. The base end portion 30a of the telescopic boom 30 is removed from the upper swing body 10, and as shown in FIG. 1, first, the operator of the crane CR makes the telescopic boom 30 horizontal by the rope RO attached to the hook HO. Lift up to become. Then, the telescopic boom 30 is moved little by little in the up-down direction, the left-right direction, and the front-rear direction, so that the insertion holes 38a1, 39a1 of the outer boom foot 38a, 39a and the insertion holes 38b1, 39b1 of the inner boom foot 38b, 39b are attached to the mounting bracket 14R, Alignment is performed with respect to the 14L insertion holes 14a and 14b.

  Thus, when the insertion hole 38a1 of the outer boom foot 38a and the insertion hole 38b1 of the inner boom foot 38b are aligned with the insertion hole 14a of the right mounting bracket 14R on the right side of the base end portion 30a of the telescopic boom 30, the boom foot pin The attachment / detachment device 50R is operated so as to extend, and the boom foot pin 40R is inserted into each insertion hole 38b1, 14a, 38a1. Similarly, when the insertion hole 39a1 of the outer boom foot 39a and the insertion hole 39b1 of the inner boom foot 39b are aligned with the insertion hole 14b of the left mounting bracket 14L on the left side of the base end 30a of the telescopic boom 30, the boom foot pin The attachment / detachment device 50L is operated so as to extend, and the boom foot pin 40L is inserted into the insertion holes 39b1, 14b, 39a1. Thus, the installation of the telescopic boom 30 is completed.

  Next, an operation for removing the telescopic boom 30 from the upper swing body 10 will be described. The base end 30a of the telescopic boom 30 is attached to the upper swing body 10, and as shown in FIG. 1, the operator of the crane CR makes the telescopic boom 30 horizontal by the rope RO attached to the hook HO. Lift it up like so. At this time, the operator of the crane CR does not apply load (the weight or lifting force of the base end portion 30a of the telescopic boom 30) to the boom foot pins 40R, 40L from the outer boom feet 38a, 39a and the inner boom feet 38b, 39b. The tension of the rope RO hanging the base end portion 30a of the telescopic boom 30 is adjusted appropriately.

  Thereafter, on the right side of the base end portion 30a of the telescopic boom 30, the boom foot pin attaching / detaching device 50R is operated so as to contract, and the boom foot pin 40R is extracted from the insertion holes 38a1, 14a, 38b1. Similarly, on the left side of the base end portion 30a of the telescopic boom 30, the boom foot pin attaching / detaching device 50L is operated so as to contract, and the boom foot pin 40L is extracted from the insertion holes 39a1, 14b, 39b1. Thus, the removal of the telescopic boom 30 is completed.

  By the way, since the telescopic boom 30 is large and heavy, the operator of the crane CR lifts the telescopic boom 30 so as to be horizontal while aligning the center of gravity of the telescopic boom 30 with the rope RO of the crane CR. It is difficult. For this reason, when the telescopic boom 30 is removed from the upper swing body 10, the weight of the base end portion 30a of the telescopic boom 30 greatly acts on the boom foot pins 40R and 40L via the outer boom feet 38a and 39a and the inner boom feet 38b and 39b. To do. Accordingly, the boom foot pins 40R and 40L are difficult to remove due to the frictional force.

  If the tension of the rope RO that suspends the base end 30a of the telescopic boom 30 is insufficient, the base end 30a of the telescopic boom 30 falls when the boom foot pins 40R and 40L are pulled out. Thus, there is a risk of damaging a hose or the like provided in the upper swing body 10. On the other hand, even if the tension of the rope RO hanging the base end portion 30a of the telescopic boom 30 is too large, when the boom foot pins 40R, 40L are pulled out, the base end portion 30a of the telescopic boom 30 suddenly rises, Risk of danger. Thus, it is difficult to extract the boom foot pins 40R, 40L, and even if the boom foot pins 40R, 40L can be extracted, there is a problem that the base end portion 30a of the telescopic boom 30 lifted by the crane CR greatly moves up and down. It was.

  Therefore, the boom detaching structure BD of the present embodiment is configured to solve the above-described problems. Specifically, as shown in FIG. 4, a hydraulic cylinder 70R is attached to the lower side of the right mounting bracket 14R, and a hydraulic cylinder 70L is attached to the lower side of the left mounting bracket 14L. In these hydraulic cylinders 70R and 70R, the cylinder body 71 is fixed to the mounting brackets 14R and 14L via brackets, and the cylinder rod 72 can move (extend and contract) in the vertical direction with respect to the cylinder body 71. .

  And when operating each hydraulic cylinder 70R, 70L, as shown in FIG. 4, the piping 75 connected to the lower side of the cylinder main body 71 and the piping 61 provided in the hydraulic drive device 60 are connected. Further, the pipe 76 connected to the upper side of the cylinder body 71 and the pipe 62 provided in the hydraulic drive device 60 are connected.

As a result, when the pressure oil is supplied from the hydraulic drive device 60 to the lower side of the cylinder body 71 through the pipe 61 and the pipe 75, the cylinder rod 72 moves upward, and the hydraulic cylinders 70R and 70L reach the stroke end. Stretch. On the other hand, when pressure oil is supplied from the hydraulic drive device 60 through the pipe 62 and the pipe 76 to the upper side of the cylinder body 71, the cylinder rod 72 is supplied.
Moves downward, and the hydraulic cylinders 70R and 70L contract to the stroke end. In the cab 11 of the earth drill 1, the operation of the hydraulic drive device 60, that is, the expansion and contraction of the hydraulic cylinders 70R and 70L is operated.

  Here, FIG. 6 is an enlarged side view of a portion C in FIG. As shown in FIG. 6, an upward block 73 is attached to the tip of the cylinder rod 72 of each hydraulic cylinder 70R, 70L. Moreover, as shown in FIG. 4, the downward block 80 is attached to the lower side of the inner side boom foot 38b, 39b. The downward block 80 and the upward block 73 are engaged with each other to align the positions (axial center positions) of the insertion holes 38a1, 14a, 38b1 and the insertion holes 39a1, 14b, 39b1. Hereinafter, the downward block 80 and the upward block 73 will be described in detail.

  FIG. 7 is an enlarged side view of the inner boom feet 38b and 39b and the downward block 80 shown in FIG. In addition, since each downward block 80 attached to the inner boom foot 38b, 39b has the same configuration, the downward block 80 attached to the inner boom foot 38b will be described as a representative. As shown in FIG. 7, the downward block 80 is formed in a substantially columnar shape, and is welded to the lower surface 38b2 of the inner boom foot 38b at its upper surface 80a. The lower surface 38b2 of the inner boom foot 38b extends obliquely upward toward the rear. In addition, joining of the downward block 80 and the inner side boom foot 38b is not restricted to welding, It can change suitably. A convex portion 80 c that protrudes downward is formed on the lower surface 80 b of the downward block 80. This convex part 80c protrudes conically with respect to the horizontal direction.

  FIG. 8 is an enlarged side view of the hydraulic cylinders 70R and 70L and the upward block 73 shown in FIG. Since the upward blocks 73 attached to the hydraulic cylinders 70R and 70L have the same configuration, the upward block 73 attached to the hydraulic cylinder 70R will be described as a representative. As shown in FIG. 8, the upward block 73 is formed in a cylindrical shape having a bottom portion on the upper side, and is assembled to the distal end portion of the cylinder rod 72 through a lower fitting hole 73a. That is, the upward block 73 is configured as a cylinder head. A recess 73 c that is recessed downward is formed on the upper surface 73 b of the upward block 73. The recess 73c is recessed conically with respect to the horizontal direction. Further, a shim 74 is interposed in the fitting hole 73a of the upward block 73, and the height position of the recess 73c can be adjusted by the shim 74.

  Next, the positional relationship between the downward block 80 and the upward block 73 will be described. FIG. 8 shows a state in which the cylinder rods 72 of the hydraulic cylinders 70R and 70L are extended upward, and the cylinder rod 72 can move up and down by the stroke S1. In this embodiment, the stroke S1 is set to about 35 mm, but can be changed as appropriate. When the cylinder rod 72 extends upward, the insertion holes 38a1, 14a, 38b1 and the insertion holes 39a1, 14b, 39b1 are aligned with the recess 73c of the upward block 73 and the downward direction. The protrusion 80c of the block 80 is set so as to be fitted (see FIG. 6).

  In other words, if the convex part 80c of the downward block 80 and the concave part 73c of the upward block 73 are fitted when the cylinder rod 72 extends upward, the insertion holes 38a1, 14a, 38b1 and the The height position of the recess 73c of the upward block 73 is adjusted so that the positions of the insertion holes 39a1, 14b, 39b1 are aligned. Thus, the inner boom foot 38b, 39b, that is, the base end portion 30a of the telescopic boom 30 is supported by the hydraulic cylinders 70R, 70L by fitting the concave portion 73c of the upward block 73 and the convex portion 80c of the downward block 80 together. Will be.

  Here, FIG. 9 is a cross-sectional view of the upward block 73 and the downward block 80 shown in FIG. In the present embodiment, as shown in FIG. 9, the inclination angle θ1 of the convex portion 80c of the downward block 80 with respect to the horizontal direction is set to 15 degrees. On the other hand, the inclination angle θ2 with respect to the horizontal direction of the recess 73c of the upward block 73 is set to 14 degrees. That is, the inclination angle θ1 of the convex portion 80c having a conical shape is slightly larger than the inclination angle θ2 of the concave portion 73c having a conical shape.

  The reason is based on the following. In other words, in order for the convex portion 80c having a conical shape and the concave portion 73c having a conical shape to be fitted at a correct position, the apex portion p1 of the convex portion 80c and the apex portion p2 of the concave portion 73c need to match. Here, if the convex portion 80c and the concave portion 73c are formed so that the inclination angle θ1 and the inclination angle θ2 are the same, the inclination angle θ1 may be smaller than the inclination angle θ2 due to a manufacturing error or the like. In this case, the apex portion p1 of the convex portion 80c and the apex portion p2 of the concave portion 73c may be shifted without matching, and the convex portion 80c and the concave portion 73c may not be fitted at the correct position. On the other hand, if the inclination angle θ1 is set to be slightly larger than the inclination angle θ2, the apex portion p1 of the convex portion 80c and the apex portion p2 of the concave portion 73c are not affected even if the inclination angles θ1 and θ2 are slightly shifted due to manufacturing errors. Match. In this way, the inclination angle θ1 is set to be slightly larger than the inclination angle θ2 in order to fit the convex portion 80c and the concave portion 73c at the correct position without being affected by manufacturing errors or the like.

The effect of this embodiment is demonstrated. Here, since the operational effect when the right side of the telescopic boom 30 is detached and the operational effect when the left side of the telescopic boom 30 is detached are the same, the operational effect when the right side of the telescopic boom 30 is detached. Only will be described.
According to the boom detaching structure BD of the present embodiment, when the telescopic boom 30 is attached to the upper swing body 10, as shown in FIG. 8, the tip of the cylinder rod 72 of the hydraulic cylinder 70R is extended to the uppermost position. Then, while hanging the telescopic boom 30 with the rope RO of the crane CR, as shown in FIG. 6, the downward block 80 of the inner boom foot 38b is engaged with the upward block 73 of the hydraulic cylinder 70R. Thereby, the positions of the insertion holes 38a1 and 38b1 of the boom foot 38a and 38b are aligned with the insertion holes 14a of the right mounting bracket 14R. At this time, the telescopic boom 30 can be attached to the upper swing body 10 by inserting the boom foot pins 40R into the respective insertion holes 38a1, 14a, 38b1.

  Thus, the engagement between the downward block 80 and the upward block 73 makes it easy to align the insertion holes 38a1, 14a, 38b1, and the work load for inserting the boom foot pin 40R and Work time can be reduced. Then, after the telescopic boom 30 is attached to the upper swing body 10, when the telescopic boom 30 is raised and lowered relative to the upper swing body 10, each boom foot 38a, 38b is not interfered with the cylinder rod 72 of the hydraulic cylinder 70R. The tip of the cylinder rod 72 of the hydraulic cylinder 70R is contracted downward most.

  On the other hand, when the telescopic boom 30 is removed from the upper swing body 10, the tip of the cylinder rod 72 of the hydraulic cylinder 70R is extended to the uppermost position so that the upper block 73 of the hydraulic cylinder 70R becomes the lower block 80 of the inner boom foot 38b. Engage. As a result, the inner boom foot 38b (base end portion 30a of the telescopic boom 30) is supported by the hydraulic cylinder 70R, and the base end portion 30a of the telescopic boom 30 is slightly lifted. Accordingly, the weight of the base end portion 30a of the telescopic boom 30 does not act on the boom foot pin 40R via the boom foot 38a, 38b, and the boom foot pin 40R can be easily pulled out.

  When the operator of the crane CR lifts the telescopic boom 30 with the rope RO, the base end portion 30a of the telescopic boom 30 is slightly lowered from the distal end portion (the right end portion in FIG. 1) of the telescopic boom 30. The base end 30a of the telescopic boom 30 may be moved toward the hydraulic cylinder 70R. Thereby, when the boom foot pin 40R is extracted, the base end portion 30a of the telescopic boom 30 does not rise rapidly. Further, since the inner boom foot 38b is supported by the hydraulic cylinder 70R, the base end portion 30a of the telescopic boom 30 does not fall.

  Thus, when the boom foot pin 40R is extracted, the vertical movement of the base end portion 30a of the telescopic boom 30 lifted by the crane CR can be suppressed, and the work of removing the telescopic boom 30 from the upper swing body 10 can be performed safely. it can. In addition, when removing the telescopic boom 30 from the upper swing body 10, the operator of the crane CR does not need an advanced operation technique for finely adjusting the horizontal center while adjusting the center of gravity of the telescopic boom 30 with the rope RO. Therefore, the work time and work load for extracting the boom foot pin 40R can be reduced.

  Further, according to the boom attachment / detachment structure BD of the present embodiment, as shown in FIG. 9, the convex portion 80 c is formed on the lower surface 80 b of the downward block 80, and the concave portion 73 c is formed on the upper surface 73 b of the upward block 73. Yes. By fitting the convex portion 80c and the concave portion 73c, it is possible to reliably grasp the state where the alignment of the insertion holes 38a1, 14a, 38b1 is completed and the state where the support of the inner boom foot 38b is completed by the hydraulic cylinder 70R. . Particularly, by fitting the conical convex portion 80c and the conical concave portion 73c, it is possible to perform alignment in all directions of the front-rear direction, the left-right direction, and the up-down direction at the same time.

  Further, according to the boom detaching structure BD of the present embodiment, the operation of the hydraulic cylinder 70R is only the operation of extending the cylinder rod 72 most upward and the operation of contracting the cylinder rod 72 downward most, and the downward block 80 and the upward block 73 is aligned so that it engages (fits) when the cylinder rod 72 of the hydraulic cylinder 70R extends upward. Therefore, when the downward block 80 and the upward block 73 are engaged, the cylinder rod 72 of the hydraulic cylinder 70R may be extended to the uppermost position, and the height of the cylinder rod 72 (upward block 73) is sufficient. There is no need to fine-tune the position. Therefore, it is very easy to operate the hydraulic cylinder 70R when the downward block 80 and the upward block 73 are engaged.

Next, a modified embodiment will be described.
The configuration of the boom detaching structure of the modified embodiment and the configuration of the boom detaching structure BD of the present embodiment described above are the same except that the shape of the concave portion of the upward block and the shape of the downward block convex portion are different. Only the upward block and the downward block of the modified embodiment will be described. FIG. 10 is a perspective view showing the upward block 77 and the downward block 90 of the modified embodiment.

  As shown in FIG. 10, a recess 77 b that is recessed downward is formed on the upper surface 77 a of the upward block 77. The recess 77b has a triangular prism shape that is recessed in a V shape when viewed from the left-right direction. On the other hand, on the lower surface 90a of the downward block 90, a convex portion 90b protruding downward is formed. The convex portion 90b has a triangular prism shape protruding in a V shape when viewed from the left-right direction. When the convex portions 90b and the concave portions 77b are fitted, the insertion holes 38a1, 14a, and 38b1 described above are set so as to be aligned.

  When fitting the convex portion 90b and the concave portion 77b, among the alignment of the insertion holes 38a1, 14a, 38b1, the alignment in the front-rear direction and the vertical direction is performed at the same time, but the alignment in the left-right direction is not performed. . However, there is no particular problem with this. That is, when the telescopic boom 30 is attached to the upper swing body 10, as shown in FIG. 4, the inner boom foot 38b is guided to the inner surface of the guide portion 14x, and the outer boom foot 38a is guided to the outer surface of the right mounting bracket 14R. . Further, the inner boom foot 39b is guided on the inner surface of the guide portion 14y, and the outer boom foot 39a is guided on the outer surface of the left mounting bracket 14L.

  In this way, the position in the left-right direction is defined at the base end portion 30 a of the telescopic boom 30. Therefore, when fitting the triangular prism-shaped convex part 90b and the triangular prism-shaped concave part 77b, there is no particular problem even if the horizontal alignment of the insertion holes 38a1, 14a, 38b1 is not performed. As can be seen from the above description, the shape of the convex portion and the concave portion is not limited to the conical shape as in the above-described embodiment, and can be appropriately changed, and may be, for example, a quadrangular pyramid shape.

As mentioned above, although embodiment of the boom attachment / detachment structure concerning this invention was described, this invention is not limited to this embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in the present embodiment, the convex portion 80c is formed on the lower surface 80b of the downward block 80, and the concave portion 73c is formed on the upper surface 73b of the upward block 73, but the concave portion is formed on the lower surface 80b of the downward block 80, A convex portion may be formed on the upper surface 73 b of the upward block 73.
In the present embodiment, the downward block 80 is attached to the lower side of the inner boom feet 38b and 39b. However, the downward block 80 may be attached to the lower side of the outer boom feet 38a and 39a.
In addition, the base end portion 30a of the telescopic boom 30 has a structure in which the boom foot pins 40R and 40L are inserted on both the left and right sides, but may have a structure in which a single boom foot pin is inserted.
Moreover, although the boom detachable structure BD of the present embodiment is applied to the telescopic boom 30 that expands and contracts in two stages, the structure of the boom to which the boom detachable structure BD is applied can be changed as appropriate, for example, expands and contracts to three or more stages. The present invention may be applied to a telescopic boom or a lattice boom.

BD Boom Desorption Structure 1 Earth Drill 10 Upper Revolving Body 14R Right Side Mounting Bracket 14L Left Side Mounting Bracket 20 Lower Traveling Body 30 Telescopic Boom 30a Base Ends 38a, 39a Outer Boom Foot 38a1, 39a1 Insertion Hole 38b, 39b Inner Boom Foot 38b1, 39b1 Insertion Hole 40R, 40L Boom foot pin 50R, 50L Boom foot pin attaching / detaching device 60 Hydraulic drive device 70R, 70L Hydraulic cylinder 71 Cylinder body 72 Cylinder rod 73, 77 Upward block 73c, 77b Recessed portion 80, 90 Downward block 80c, 90b Convex portion

Claims (5)

The mounting bracket provided on the upper swing body of the construction machine extends in the front-rear direction of the boom,
A boom foot provided at the base end of the boom extends in parallel with the mounting bracket,
The mounting bracket and the boom foot are formed with insertion holes extending in the left-right direction perpendicular to the front-rear direction of the boom, respectively.
The boom foot pin is inserted into the insertion hole of the boom foot and the insertion hole of the mounting bracket so that the boom is attached to the upper swing body, and the boom foot pin is inserted from the insertion hole of the boom foot and the insertion hole of the mounting bracket. In the boom detaching structure in which the boom is removed from the upper swing body by pulling out,
The upper revolving body is provided with a hydraulic cylinder that is extendable in the vertical direction at the tip , and is disposed immediately below the insertion hole of the boom foot and the insertion hole of the mounting bracket .
A downward block attached to the lower side of the boom foot and an upward block attached to the tip of the hydraulic cylinder in a state where the insertion hole of the boom foot and the insertion hole of the mounting bracket are aligned. A boom attachment / detachment structure characterized by being provided to be engaged. The boom attachment / detachment structure according to claim 1,
One of the lower surface of the downward block and the upper surface of the upward block is formed with a depressed recess,
A boom attachment / detachment structure, wherein a convex portion that fits into the concave portion is formed on the other of the lower surface of the downward block and the upper surface of the upward block. In the boom detaching structure according to claim 2,
The recess is recessed conically with respect to the horizontal direction,
The boom attaching / detaching structure is characterized in that the convex portion protrudes in a conical shape with respect to a horizontal direction. In the boom attachment / detachment structure according to claim 3,
The recess is formed on the upper surface of the upward block,
The convex portion is formed on the lower surface of the downward block,
The boom attachment / detachment structure characterized in that an inclination angle of the convex portion with respect to the horizontal direction is slightly larger than an inclination angle of the concave portion with respect to the horizontal direction. In the boom detaching structure according to any one of claims 1 to 4,
The boom attachment / detachment structure is characterized in that the downward block and the upward block are aligned so as to be engaged when a tip end portion of the hydraulic cylinder extends upward.

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