JP5054744B2 - Two-member connecting device - Google Patents

Description

  The present invention relates to a two-member connecting device suitably used to connect two members such as a swing frame of a hydraulic excavator and a boom, for example.

  In general, a hydraulic excavator as a representative example of a construction machine has a vehicle body composed of a self-propelled lower traveling body and an upper revolving body mounted on the lower traveling body so as to be able to swivel. A working device is provided on the front side of the body so as to move up and down. For example, when dismantling a structure having a high ground height such as a high-rise building, a hydraulic excavator in which a work device for dismantling work is attached to the front side of the upper swing body is preferably used.

  Here, the disassembling work device usually has a plurality of booms called multi-booms, and the multi-booms are lower joints that are pivotally connected to brackets provided on the upper revolving body so that the base end side is pivotable. A boom and an upper boom attached to the distal end side of the lower boom are configured. A middle arm is pin-coupled to the distal end side of the upper boom, an arm is pin-coupled to the distal end side of the middle arm, and a working tool such as a crusher is attached to the distal end side of the arm. .

  By the way, when a hydraulic excavator for this type of dismantling work is transported to the work site, the hydraulic excavator is usually divided into a vehicle body and a work device by removing the work device from the upper swing body, and the vehicle body and the work device. The equipment is loaded on a transport vehicle and transported separately to the work site. And, at the work site, by assembling the work device to the body (upper turning body) of the hydraulic excavator, the work device is used to perform dismantling work on structures with a large ground height (patent) Reference 1).

JP 11-193543 A

  By the way, when assembling the above-described dismantling work device to the upper revolving structure on the vehicle body side at the work site, for example, only the lower boom is removed from the work device, and the base end side of this lower boom is connected to the connecting pin. To connect the pin to the swing frame of the upper swing body. Then, by attaching the upper boom to which the middle arm, the arm, and the work tool are attached to the distal end side of the lower boom attached to the upper swing body, the work device is assembled to the upper swing body.

  Here, when the lower boom is attached to the upper swing body, a pin insertion hole provided on the base end side of the lower boom and a bracket provided on the swing frame in a state where the lower boom is lifted using a hydraulic crane or the like It is necessary to position the pin insertion hole of the lower boom side and to insert the connecting pin into the pin insertion hole on the lower boom side and the pin insertion hole on the bracket side.

  However, since the lower boom is lifted by a hydraulic crane or the like, it is difficult to accurately align (center) the pin insertion hole of the lower boom and the pin insertion hole of the bracket on the revolving frame side. As a result, there is a problem that a great amount of time is spent on the work of pin-connecting the bracket and the lower boom using the connecting pins, and the workability is lowered.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a two-member connecting device that can improve workability when two members are connected using a connecting pin. Yes.

  In order to solve the above-described problems, the present invention provides a first member having left and right brackets provided facing each other in the left and right directions, and a left member provided on each of the left and right brackets of the first member. , A right first pin insertion hole, and cylindrical left and right first bushes fitted in the left and right first pin insertion holes, respectively, and detachably connected to the first member. A second member, a second pin insertion hole provided in the second member, and a cylinder that is inserted into the second pin insertion hole and disposed on the same hole axis as the left and right first bushes. And a connecting pin inserted between the inner peripheral side of the left and right first bushes and the inner peripheral side of the second bush and connecting between the first member and the second member. This is applied to a two-member connecting device formed by

  The feature of the structure adopted by the invention of claim 1 is that the left and right first bushes are inserted into the left and right first pin insertion holes and the left and right first bushes. It is formed as a single cylindrical body composed of protrusions protruding left and right from the end face position of the bracket, and the second member is engaged with the protrusions of the left and right first bushes from the outer peripheral side. Thus, a centering member is provided for aligning the hole axis of the second bush with the hole axis of the left and right first bushes.

  The invention of claim 2 is characterized in that the centering member is disposed in a portion of the second member that faces the end surface of the left and right brackets in the left and right directions. The member is configured to simultaneously engage with the protruding portions of the left and right first bushes.

  According to a third aspect of the present invention, the centering member has an arcuate engagement surface curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion of the left and right first bushes. The center of the mating surface is arranged on the same axis as the hole axis of the second bush.

  According to a fourth aspect of the present invention, the alignment member is configured to be provided integrally with the second member or attachable and detachable.

  According to the first aspect of the present invention, the centering member provided on the second member is engaged from the outer peripheral side with the protruding portions of the left and right first bushes protruding from the end face positions of the left and right brackets. The hole axis of the second bush can be made to coincide with the hole axis of the left and right first bushes. As a result, the connecting pin can be easily inserted into the left and right first bushes provided on the left and right brackets and the second bush provided on the second member, and the first member and the second member. The workability when connecting the two using a connecting pin can be improved.

  According to the invention of claim 2, the left and right alignment members provided on the second member are simultaneously engaged with the outer peripheral sides of the left and right first bushes protruding from the left and right brackets, The posture of the second member with respect to the left and right brackets can be stabilized, and the hole axes of the left and right first bushes can be accurately matched with the hole axes of the left and right second bushes. As a result, it is possible to further improve the workability when the connecting pins are inserted into the first bushes provided on the left and right brackets and the second bushes provided on the second member.

  According to the invention of claim 3, since the center of the arcuate engagement surface of the alignment member provided on the second member is arranged on the same axis as the hole axis of the second bush, the arcuate engagement of the alignment member By engaging the mating surface with the outer peripheral surface of the first bush, the hole axis of the second bush provided on the second member is automatically set with respect to the hole axis of the left and right first bushes provided on the first member. Can be matched (aligned). As a result, the hole axes of the left and right first bushes can be quickly aligned with the hole axes of the left and right second bushes, and the left and right first bushes provided on the left and right brackets The connecting pin can be quickly and easily inserted into the second bush provided on the second member.

  According to the invention of claim 4, when the centering member is attached to the second member and provided so as to be removable, for example, the work of processing the end surface of the second member where the second pin insertion hole opens, When performing the operation of inserting the second bush into the second pin insertion hole, the centering member can be removed from the second member, and the end surface processing of the second member and the insertion of the second bush are performed. Workability at the time can be improved.

  On the other hand, when the centering member is integrally fixed to the second member, the center of the arcuate engagement surface of the centering member and the hole axis of the second bush can be accurately matched, The workability when inserting the connecting pin into the left and right first bushes and the second bush can be further enhanced.

1 is a front view showing a multi-boom hydraulic excavator to which a two-member coupling device according to an embodiment of the present invention is applied. It is a front view which shows the state which connects a lower boom to the bracket of a turning frame. It is a front view of the principal part expansion which expands and shows a bracket, a lower boom, an alignment member, a connection pin, etc. It is the top view which looked at the bracket, the lower boom, the alignment member, the connection pin, etc. from the arrow IV-IV direction in FIG. It is sectional drawing which looked at the bracket, the lower boom, the alignment member, the connection pin, etc. from the arrow VV direction in FIG. It is a disassembled perspective view which shows a bracket, a lower boom, an alignment member, the 1st, 2nd bush, etc. It is the front view which looked at the bracket, the lower boom, the connection pin, the rotation stop member, etc. from the arrow VII-VII direction in FIG. It is a front view similar to FIG. 3 which shows the state which attaches a lower boom to a bracket. It is a top view similar to FIG. 4 which shows the state which attaches a lower boom to a bracket. It is a top view similar to FIG. 4 which shows the state which inserts a connection pin in the 1st bush of a bracket, and the 2nd bush of a lower boom. It is the same front view as FIG. 3 which shows the alignment member by the 2nd Embodiment, a bracket, a lower boom, a connection pin, etc. It is the top view which looked at the alignment member, the bracket, the lower boom, the connection pin, etc. from the arrow XII-XII direction in FIG. It is sectional drawing which looked at the bracket, the lower boom, the alignment member, the connection pin, etc. from the arrow XIII-XIII direction in FIG. It is a top view similar to FIG. 4 which shows the alignment member by the 3rd Embodiment, a bracket, a lower boom, a connection pin, etc. It is sectional drawing which saw the alignment member, the bracket, the lower boom, the connection pin, etc. from the arrow XV-XV direction in FIG. It is a front view similar to FIG. 3 which shows the alignment member by the 4th Embodiment, a bracket, a lower boom, a connection pin, etc. It is the top view which looked at the alignment member, the bracket, the lower boom, the connection pin, etc. from the arrow XVII-XVII direction in FIG.

  Hereinafter, an embodiment of a two-member connecting device according to the present invention will be described by taking as an example a case where a lower boom constituting a multi-boom of a hydraulic excavator and a bracket of an upper swing body are connected with reference to the accompanying drawings. The details will be described.

  First, FIGS. 1 to 10 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a hydraulic excavator as a typical example of a construction machine. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2 and an upper portion mounted on the lower traveling body 2 so as to be able to turn. The revolving structure 3 and a work device 8 (described later) provided on the front side of the upper revolving structure 3 so as to be able to move up and down are roughly configured to dismantle a structure having a high ground height such as a high-rise building. It is used suitably for.

  Here, the upper revolving structure 3 is disposed on the rear end side of the revolving frame 4, the cab 5 that is disposed on the left side of the front portion of the revolving frame 4 and that defines the cab. The counterweight 6 and a building cover 7 that is disposed on the front side of the counterweight 6 and houses equipment (not shown) such as an engine and a hydraulic pump are roughly constituted. A left bracket 22 and a right bracket 25, which will be described later, are integrally provided on the front side of the revolving frame 4, and a lower boom 9 of the working device 8 described later is rotated on the left and right brackets 22 and 25. It becomes the structure connected so that it is possible.

  Reference numeral 8 denotes a multi-boom working device that is attached to the front side of the upper swing body 3 so as to be able to move up and down. The working device 8 includes a multi-boom including a lower boom 9, a joint boom 10, and an upper boom 11, A middle arm 12 pivotably attached to the distal end side of the boom 11, an arm composed of a lower arm 13 and an upper arm 14 pivotably attached to the distal end side of the middle arm 12, and a distal end side of the upper arm 14 And a crusher 15 as a working tool that is rotatably attached to the main body.

  Here, the lower boom 9 is formed of a rectangular tube having a square cross-sectional shape as a whole, and as shown in FIGS. 4 and 6, the lower boom 9 has a bifurcated left, Right boom foot portions 9A and 9B are provided. The left and right boom foot portions 9A and 9B provided on the lower boom 9 can be rotated to the left and right brackets 22 and 25 of the revolving frame 4 via left and right connecting pins 30 and 32, which will be described later. It is the structure connected to.

  By the way, when transporting the excavator 1 to the work site, for example, by removing the work device 8 from the upper swing body 3, the vehicle body composed of the lower traveling body 2 and the upper swing body 3 and the work device 8 are transferred to the transport vehicle. Load and transport to work site separately. When the work device 8 is attached to the upper swing body 3 at the work site, first, as shown in FIG. 2, the lower boom 9 of the work device 8 is lifted by the hydraulic crane 16, and the two-member connecting device 21 described later is used. Thus, the left and right boom foot portions 9A and 9B of the lower boom 9 are connected to the left and right brackets 22 and 25 of the revolving frame 4, respectively. That is, in the present embodiment, the case where the swing frame 4 of the upper swing body 3 is applied as the first member and the lower boom 9 of the work device 8 is applied as the second member is illustrated.

  Next, 21 shows a two-member connecting device according to the present embodiment, and this two-member connecting device 21 connects between the turning frame 4 as the first member and the lower boom 9 as the second member. It is. The two-member connecting device 21 includes left and right brackets 22 and 25, left and right first pin insertion holes 22C and 25C, left and right inner first bushes 23 and 26, and left and right outer sides. First bushes 24 and 27, left and right boom foot portions 9A and 9B of the lower boom 9, left and right second pin insertion holes 9C, left and right second bushes 28 and 29, left and right connecting pins 30 32, left and right alignment members 35, 37, and the like.

  Reference numeral 22 denotes a left bracket integrally provided on the front side of the revolving frame 4 serving as a first member. The left bracket 22 is a left vertical plate standing on a bottom plate (not shown) of the revolving frame 4. It is comprised by the front-end part, and protrudes in the shape of a mountain from the bottom plate upwards. Here, as shown in FIGS. 4 and 6, the left bracket 22 is composed of a left inner bracket 22A and a left outer bracket 22B that face each other in the left and right directions at a constant interval. The outer bracket 22B is formed using a thick steel plate or the like. A left boom foot portion 9A of the lower boom 9 is arranged between the left inner bracket 22A and the left outer bracket 22B.

  Further, a left first pin insertion hole 22C is provided in the left and right directions on the upper end side of the left inner bracket 22A and the upper end side of the left outer bracket 22B, respectively, and these two left first pin insertions are made. The holes 22C are arranged on the same hole axis AA. A left first pin insertion hole 22C, which will be described later, is inserted into the left first pin insertion hole 22C formed in the left inner bracket 22A, and the left first pin insertion hole 22C formed in the left outer bracket 22B. Is configured to be fitted with a left outer first bush 24 described later.

  23 indicates a left inner first bush fitted into the left first pin insertion hole 22C of the left inner bracket 22A. The left inner first bush 23 is formed as a thin cylindrical body, as shown in FIG. It has an axial dimension substantially equal to the thickness dimension of the left inner bracket 22A. The left inner first bush 23 is inserted into the left first pin insertion hole 22C in a press-fitted state, and a left connecting pin 30 described later is inserted into the inner peripheral side of the left inner first bush 23. It has become.

  Reference numeral 24 denotes a left outer first bush fitted into the left first pin insertion hole 22C of the left outer bracket 22B. The left outer first bush 24 has a cylindrical shape having a wall thickness equal to that of the left inner first bush 23. As shown in FIG. 5, it has an axial dimension larger than the thickness dimension of the left outer bracket 22B. That is, the left outer first bush 24 is inserted into the left first pin insertion hole 22C, and the insertion part 24A is inserted into the left first pin insertion hole 22C, and the insertion part 24A is inserted into the left first pin insertion hole 22C. A single cylindrical body is formed by a projecting portion 24B projecting leftward and rightward from the outer end surface 22B1 of the left outer bracket 22B.

  An insertion portion 24A of the left outer first bush 24 is press-fitted into the left first pin insertion hole 22C, and a left connecting pin 30 described later is provided on the inner peripheral side of the left outer first bush 24. It is configured to be inserted. In addition, a left centering member 35 described later is engaged with the protruding portion 24B protruding from the outer end surface 22B1 of the left outer bracket 22B from the outer peripheral side.

  A right bracket 25 is integrally provided on the front side of the swivel frame 4 serving as the first member. The right bracket 25 is a right vertical plate standing on a bottom plate (not shown) of the swivel frame 4. It is comprised by the front-end part, and protrudes in the mountain shape toward the upper direction facing the left bracket 22 in the left and right directions. Here, like the left bracket 22, the right bracket 25 is composed of a right inner bracket 25A and a right outer bracket 25B facing each other in the left and right directions at regular intervals, and the right inner bracket 25A and the right outer bracket 25B. The right boom foot part 9B of the lower boom 9 is arranged between the two.

  Further, a right first pin insertion hole 25C is provided in the left and right directions at the upper end side of the right inner bracket 25A and the upper end side of the right outer bracket 25B, respectively, and these two right first pin insertions are made. The holes 25C are arranged on the same hole axis AA. A right first pin insertion hole 25C formed in the right inner bracket 25A is fitted with a right inner first bush 26 described later, and the right first pin insertion hole 25C formed in the right outer bracket 25B. Is configured to be fitted with a right outer first bush 27 described later.

  Reference numeral 26 denotes a right inner first bush fitted into the right first pin insertion hole 25C of the right inner bracket 25A. The right inner first bush 26 is formed as a thin cylindrical body, and has a thickness of the right inner bracket 25A. It has an axial dimension approximately equal to the dimension. The right inner first bush 26 is inserted into the right first pin insertion hole 25C in a press-fitted state, and a right connecting pin 32 (described later) is inserted into the inner peripheral side of the right inner first bush 26. It has become.

  Reference numeral 27 denotes a right outer first bush fitted into the right first pin insertion hole 25C of the right outer bracket 25B. The right outer first bush 27 has a cylindrical shape having a wall thickness equal to that of the right inner first bush 26. And has an axial dimension larger than the thickness dimension of the right outer bracket 25B. That is, the right outer first bush 27 is inserted into the right first pin insertion hole 25C, and the insertion part 27A is inserted into the right first pin insertion hole 25C. A single cylindrical body is formed by the protruding portion 27B protruding leftward and rightward from the outer end face 25B1 of the right outer bracket 25B.

  The insertion portion 27A of the right outer first bush 27 is press-fitted into the right first pin insertion hole 25C, and a right connecting pin 32 (to be described later) is provided on the inner peripheral side of the right outer first bush 27. It is configured to be inserted. In addition, a right alignment member 37, which will be described later, is engaged with the protruding portion 27B protruding from the outer end surface 25B1 of the right outer bracket 25B from the outer peripheral side.

  On the other hand, the left and right boom foot portions 9A and 9B described above are provided facing each other in the left and right directions on the base end side of the lower boom 9 as the second member. The left boom foot portion 9A is disposed between the left inner bracket 22A and the left outer bracket 22B of the left bracket 22, and the right boom foot portion 9B is disposed between the right inner bracket 25A and the right outer bracket 25B of the right bracket 25. It is the composition arranged in.

  Here, the left and right boom foot portions 9A and 9B are respectively provided with second pin insertion holes 9C penetrating in the left and right directions, and the second pin insertion holes 9C are formed in the left and right brackets 22 respectively. , 25 corresponding to the left and right first pin insertion holes 22C, 25C and set to the same diameter as the left and right first pin insertion holes 22C, 25C. The left and right second pin insertion holes 9C are configured to be fitted with left and right second bushes 28 and 29, which will be described later.

  Reference numeral 28 denotes a left second bush inserted into the second pin insertion hole 9C of the left boom foot 9A. The left second bush 28 has an axial dimension slightly smaller than the thickness of the left boom foot 9A. It is formed as a cylindrical body having. The left second bush 28 is inserted into the second pin insertion hole 9C of the left boom foot portion 9A in a press-fitted state, and the hole axis of the left second bush 28 is inserted into the left first pin insertion hole 22C of the left bracket 22. It is the structure which corresponds to hole axial line AA of the left inner side 1st bush 23 and the left outer side 1st bush 24 which were inserted.

  Reference numeral 29 denotes a right second bush inserted into the second pin insertion hole 9C of the right boom foot 9B. The right second bush 29 has an axial dimension slightly smaller than the thickness of the right boom foot 9B. It is formed as a cylindrical body having. The right second bush 29 is press-fitted into the second pin insertion hole 9C of the right boom foot 9B in a press-fitted state, and the hole axis of the right second bush 29 is inserted into the right first pin insertion hole 25C of the right bracket 25. It is configured to coincide with the hole axis AA of the inserted right inner first bush 26 and right outer first bush 27.

  Reference numeral 30 denotes a left connecting pin that rotatably connects the left bracket 22 and the left boom foot 9A of the lower boom 9. The left connecting pin 30 includes the left inner first bushing 23 and the left boom foot of the left inner bracket 22A. It is inserted into the left second bush 28 of the portion 9A and the left outer first bush 24 of the left outer bracket 22B. Here, as shown in FIG. 7, a large-diameter collar 30A is fixed to one end of the left connecting pin 30, and by engaging the collar 30A with a stopper 31 provided on the left inner bracket 22A, The left connecting pin 30 is prevented from being rotated and removed.

  Reference numeral 32 denotes a right connecting pin that rotatably connects the right bracket 25 and the right boom foot portion 9B of the lower boom 9. The right connecting pin 32 includes the right inner first bush 26 and the right boom foot of the right inner bracket 25A. It is inserted into the right second bush 29 of the portion 9B and the right outer first bush 27 of the right outer bracket 25B. Further, a hook part 32A similar to the left connection pin 30 is fixed to one end side of the right connection pin 32, and the right connection pin 32 is engaged by engaging the hook part 32A with a stopper 31 provided on the right inner bracket 25A. It is the structure which performs rotation prevention and removal prevention.

  Reference numeral 33 denotes a left mounting seat provided on the left end face 9A1 facing the left outer bracket 22B in the left and right directions in the left boom foot portion 9A of the lower boom 9. The left mounting seat 33 is a left centering member 35 described later. Is provided so that it can be attached and removed. Here, as shown in FIG. 6 and the like, the left mounting seat 33 is fixed to a position separated from the left second bush 28 by means of welding or the like. The front end side of the left mounting seat 33 protruding from the left end face 9A1 of the left boom foot portion 9A is a large-diameter flat disc portion 33A, and a plurality of bolts are inserted into the disc portion 33A at equal angular intervals. A hole 33B is formed.

  Reference numeral 34 denotes a right mounting seat provided on the right end face 9B1 facing the right outer bracket 25B in the left and right directions in the right boom foot portion 9B of the lower boom 9. The right mounting seat 34 is a right alignment member 37 which will be described later. Is provided so that it can be attached and removed. Here, the right mounting seat 34 has a disc portion 34A similar to the left mounting seat 33, and a plurality of bolt insertion holes (not shown) are formed in the disc portion 34A at equal angular intervals. ing.

  Next, reference numeral 35 denotes a left centering member according to this embodiment. The left centering member 35 is attached to the left boom foot 9A via the left mounting seat 33 so as to be removable. The left centering member 35 inserts the left connecting pin 30 into the left inner first bush 23 and the left outer first bush 24 provided on the left bracket 22 and the left second bush 28 provided on the left boom foot portion 9A. When fitted, the hole axis of the left second bush 28 is made to coincide with the hole axis AA of the left inner first bush 23 and the left outer first bush 24.

  Here, the left alignment member 35 protrudes toward the left second bush 28 of the left boom foot portion 9A from the attachment plate portion 35A attached to the disc portion 33A of the left attachment seat 33 and the left boom foot portion 9A. It is comprised by the engaging board part 35B engaged with the protrusion part 24B of the outer side 1st bush 24. As shown in FIG. A plurality of bolt insertion holes 35C are formed in the mounting plate portion 35A, and the left alignment member 35 is formed by bolts 36 inserted into the respective bolt insertion holes 35C and the respective bolt insertion holes 33B of the left mounting seat 33. It is configured to be attached to the left attachment seat 33 (see FIG. 6).

  On the other hand, as shown in FIG. 3 and the like, the engagement plate portion 35B is formed with an arcuate engagement surface 35D that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 24B of the left outer first bush 24. The arcuate engagement surface 35D is engaged with the outer peripheral surface of the protruding portion 24B of the left outer first bush 24 without a gap. The left centering member 35 is configured to be attached to the left mounting seat 33 by the bolt 36 in a state where the center P of the arcuate engagement surface 35D is disposed on the hole axis of the left second bush 28. .

  Thus, by attaching the left alignment member 35 to the left end surface 9A1 of the left boom foot 9A, when the left boom foot 9A is inserted between the left inner bracket 22A and the left outer bracket 22B, the left outer bracket 22B. The arcuate engagement surface 35D of the left centering member 35 engages with the protruding portion 24B of the left outer first bush 24 protruding from the outer end surface 22B1 from the outer peripheral side. In this case, the center of the arcuate engagement surface 35D formed on the left centering member 35 is disposed on the hole axis of the left second bush 28 provided on the left boom foot portion 9A. The arcuate engagement surface 35D of the left alignment member 35 is engaged with the outer peripheral surface of the projecting portion 24B of the 24 without any gap, so that the left inner first bush 23 and the left outer first bush 24 provided on the left bracket 22 are engaged. The hole axis line of the left second bush 28 can be exactly matched (aligned) with the hole axis line A-A.

  Reference numeral 37 denotes a right alignment member provided on the right boom foot portion 9B via the right mounting seat 34. The right alignment member 37 includes a right inner first bush 26 and a right outer first bush provided on the right bracket 25. 27 and the right second bushing 29 provided on the right boom foot 9B, when the right connecting pin 32 is inserted into the hole axis AA of the right inner first bush 26 and the right outer first bush 27, The hole axis of the right second bush 29 is made to coincide.

  Here, the right centering member 37, like the left centering member 35, is configured by a mounting plate portion 37 A and an engaging plate portion 37 B, and a bolt insertion hole and a right mounting seat that are formed in the mounting plate portion 37 A. The right centering member 37 is attached to the right mounting seat 34 by a bolt 36 inserted through a bolt insertion hole (both not shown) drilled in 34. Further, the engagement plate portion 37B is formed with an arcuate engagement surface 37C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 27B of the right outer first bush 27. The center of the arcuate engagement surface 37 </ b> C is arranged on the hole axis of the right second bush 29 and is attached to the right attachment seat 34 by the bolt 36.

  Thus, when the right boom foot 9B is inserted between the right inner bracket 25A and the right outer bracket 25B by attaching the right alignment member 37 to the right end surface 9B1 of the right boom foot 9B, the right outer bracket 25B is inserted. The arcuate engagement surface 37C of the right alignment member 37 is engaged from the outer peripheral side with the protruding portion 27B of the right outer first bush 27 protruding from the outer end surface 25B1. In this case, since the center of the arcuate engagement surface 37C formed on the right centering member 37 is disposed on the hole axis of the right second bush 29 provided on the right boom foot portion 9B, the right outer first bush The right inner first bush 26 and the right outer first bush 27 provided on the right bracket 25 are engaged with the outer peripheral surface of the projecting portion 27B of the 27 by the arcuate engagement surface 37C of the right alignment member 37 without a gap. The hole axis line of the right second bush 29 can be accurately matched (aligned) with the hole axis line A-A.

  The two-member connecting device 21 according to the present embodiment has the above-described configuration. Next, the left and right brackets 22 provided on the turning frame 4 of the excavator 1 using the two-member connecting device 21. , 25, the case where the lower boom 9 of the working device 8 is connected will be described.

  First, as shown in FIG. 2, the lower boom 9 is lifted using the hydraulic crane 16, and the lower boom 9 is lowered toward the left and right brackets 22 and 25 provided on the revolving frame 4. As shown in FIGS. 8 and 9, the left boom foot 9A of the lower boom 9 is inserted between the left inner bracket 22A and the left outer bracket 22B, and the right boom foot 9B of the lower boom 9 is Insert between the inner bracket 25A and the right outer bracket 25B.

  At this time, since the left centering member 35 is attached to the left end face 9A1 of the left boom foot 9A, as shown in FIG. 3, the left outer first bush 24 protruding from the outer end face 22B1 of the left outer bracket 22B. The arcuate engagement surface 35D of the left centering member 35 engages with the protrusion 24B from the outer peripheral side. In this case, the center P of the arcuate engagement surface 35D formed on the left centering member 35 is disposed on the hole axis of the left second bush 28 provided on the left boom foot 9A. Thereby, the left inner first bush 23 provided on the left bracket 22 in a state where the arcuate engagement surface 35D of the left centering member 35 is engaged with the outer peripheral surface of the protruding portion 24B of the left outer first bush 24. The hole axis of the left second bush 28 can be exactly matched to the hole axis AA of the left outer first bush 24.

  On the other hand, since the right alignment member 37 is attached to the right end surface 9B1 of the right boom foot portion 9B, the arcuate engagement surface 35D of the left alignment member 35 is disposed on the protrusion 24B of the left outer first bush 24 as described above. At the same time, the arcuate engagement surface 37C of the right centering member 37 engages with the protruding portion 27B of the right outer first bush 27 protruding from the outer end surface 25B1 of the right outer bracket 25B from the outer peripheral side. . In this case, the center of the arcuate engagement surface 37C formed on the right centering member 37 is disposed on the hole axis of the right second bush 29 provided on the right boom foot portion 9B. Accordingly, the right inner first bush 26 provided on the right bracket 25 in a state where the arcuate engagement surface 37C of the right centering member 37 is engaged with the outer peripheral surface of the protruding portion 27B of the right outer first bush 27, The hole axis of the right second bush 29 can be made to exactly match the hole axis AA of the right outer first bush 27.

  Accordingly, as shown in FIG. 10, the left connecting pin is connected to the left inner first bush 23 of the left inner bracket 22A, the left second bush 28 of the left boom foot 9A, and the left outer first bush 24 of the left outer bracket 22B. 30 can be easily inserted. Then, as shown in FIG. 7, the left connecting pin 30 can be prevented from being rotated and retained by engaging the flange portion 30 </ b> A of the left connecting pin 30 with a stopper 31 provided on the left inner bracket 22 </ b> A. it can.

  Similarly, the right connecting pin 32 is easily provided to the right inner first bush 26 of the right inner bracket 25A, the right second bush 29 of the right boom foot portion 9B, and the right outer first bush 27 of the right outer bracket 25B. Can be inserted. Then, by engaging the flange portion 32A of the right connecting pin 32 with the stopper 31 provided on the right inner bracket 25A, the right connecting pin 32 can be prevented from being rotated and removed.

  Accordingly, the left bracket 22 of the revolving frame 4 and the left boom foot portion 9A of the lower boom 9 can be pivotably coupled using the left coupling pin 30, and the right bracket 25 of the revolving frame 4 and the lower boom can be coupled. 9 and the right boom foot portion 9B can be rotatably connected using the right connecting pin 32.

  Thus, according to the present embodiment, the arcuate engagement surface 35D of the left centering member 35 provided on the left boom foot 9A is engaged with the protrusion 24B of the left outer first bush 24 protruding from the left outer bracket 22B. By aligning, the hole axis line of the left second bush 28 provided in the left boom foot portion 9A coincides with the hole axis line A-A of the left inner first bush 23 provided on the left bracket 22 and the left outer first bush 24. Can be made. Further, by engaging the projecting portion 27B of the right outer first bush 27 projecting from the right outer bracket 25B with the arcuate engagement surface 37C of the right alignment member 37 provided on the right boom foot portion 9B, the right bracket 25 is engaged. The hole axis line of the right second bush 29 provided in the right boom foot portion 9B can be made to coincide with the hole axis line A-A of the right inner first bush 26 and right outer first bush 27 provided in FIG.

  Thereby, the left connecting pin 30 can be easily inserted into the left inner first bush 23 of the left bracket 22, the left outer first bush 24, the left second bush 28 of the left boom foot portion 9A, and the right bracket. The right connecting pin 32 can be easily inserted into the right inner first bush 26, the right outer first bush 27, and the right second bush 29 of the right boom foot 9B. As a result, work for connecting the left and right brackets 22 and 25 of the revolving frame 4 and the left and right boom foot portions 9A and 9B of the lower boom 9 using the left and right connecting pins 30 and 32. Can increase the sex.

  Moreover, the arcuate engagement surfaces 35D and 37C of the left and right alignment members 35 and 37 provided on the lower boom 9 are simultaneously engaged with the protrusions 24B and 27B of the left and right outer first bushes 24 and 27, respectively. Thus, the posture of the lower boom 9 with respect to the left and right brackets 22 and 25 can be stabilized. Thus, the hole inner axes of the left inner first bush 23, the left outer first bush 24, and the left second bush 28 of the left boom foot portion 9A can be quickly and accurately matched, and the right inner first bush 23 of the right bracket 25 can be aligned. The bore axis of the 1 bush 26, the right outer first bush 27, and the right second bush 29 of the right boom foot portion 9B can be quickly and accurately aligned, and the left and right brackets 22 and 25 of the revolving frame 4 The workability when the left and right boom foot portions 9A and 9B of the boom 9 are connected using the left and right connecting pins 30 and 32 can be further enhanced.

  Further, the left and right alignment members 35 and 37 are attached to the left and right mounting seats 33 and 34 fixed to the left and right boom foot portions 9A and 9B by using bolts 36 so as to be removable. . Accordingly, for example, the left end surface 9A1 of the left boom foot portion 9A in which the second pin insertion hole 9C is opened and the right end surface 9B1 of the right boom foot portion 9B are processed, and the left and right second pin insertion holes 9C are left and right. Left and right alignment members 35 and 37 can be removed when the second bushes 28 and 29 are inserted and fitted, end face processing of the left and right boom foot portions 9A and 9B, Workability when inserting the left and right second bushes 28 and 29 can be improved.

  Next, FIGS. 11 to 13 show a second embodiment of the present invention. The feature of this embodiment is that the left and right centers are aligned with the mounting seats arranged on the upper surface side of the left and right boom foot parts. It is in the structure which attaches a member. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 41 denotes a two-member connecting device according to the second embodiment. This two-member connecting device 41 is substantially the same as that according to the first embodiment described above, and the left and right brackets 22 and 25. Left and right first pin insertion holes 22C and 25C, left and right inner first bushes 23 and 26, left and right outer first bushes 24 and 27, lower boom 9 left and right boom foot portions 9A, 9B, left and right second pin insertion holes 9C, left and right second bushings 28 and 29, left and right connecting pins 30 and 32, left and right alignment members 44 and 46 described later, and the like. However, the configurations of the left and right alignment members 44 and 46 are different from those according to the first embodiment.

  Reference numeral 42 denotes a left mounting seat provided on the upper surface side of the left boom foot portion 9A of the lower boom 9. The left mounting seat 42 is formed in a rectangular plate shape extending in the length direction of the lower boom 9, and the left boom foot portion 9A. It is fixed to the upper surface using a means such as welding. The left mounting seat 42 is screwed with a plurality of bolt holes (not shown).

  43 is a right mounting seat provided on the upper surface side of the right boom foot portion 9B of the lower boom 9. The right mounting seat 43 is also formed in a rectangular plate shape extending in the length direction of the lower boom 9, and the right boom foot portion 9B. It is fixed to the upper surface using a means such as welding. The right mounting seat 43 is screwed with a plurality of bolt holes (not shown).

  Reference numeral 44 denotes a left centering member provided on the left boom foot 9A via the left mounting seat 42. The left centering member 44 can be attached to and detached from the left mounting seat 42 using a plurality of bolts 45. Is provided. Here, the left alignment member 44 is attached to the left mounting seat 42 by a bolt 45 and protrudes left and right from the left end face 9A1 of the left boom foot 9A, and the protruding end of the mounting plate 44A. It is configured by an engagement plate portion 44B that faces the left end surface 9A1 of the left boom foot portion 9A by bending the side and engages with the protruding portion 24B of the left outer first bush 24.

  The engagement plate portion 44B is formed with an arcuate engagement surface 44C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protrusion 24B of the left outer first bush 24, and the arcuate engagement surface 44C is The left outer first bush 24 is engaged with the outer peripheral surface of the projecting portion 24B without a gap. The left centering member 44 is configured to be attached to the left mounting seat 42 by the bolt 45 in a state where the center P of the arcuate engagement surface 44C is disposed on the hole axis of the left second bush 28. .

  46 denotes a right centering member provided on the right boom foot 9B via the left mounting seat 43. The right centering member 46 is attached to the right mounting seat 43 by a bolt 45, like the left centering member 44. The mounting plate portion 46 </ b> A and the engaging plate portion 46 </ b> B that engages with the protruding portion 27 </ b> B of the right outer first bush 27. The engagement plate portion 46B is formed with an arcuate engagement surface 46C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 27B of the right outer first bush 27. The right outer first bush 27 is engaged with the outer peripheral surface of the projecting portion 27B without a gap. The right centering member 46 is configured to be attached to the right mounting seat 43 by the bolt 45 in a state where the center of the arcuate engagement surface 46C is disposed on the hole axis of the right second bush 29.

  The two-member connecting device 41 according to the present embodiment has the left and right alignment members 44 and 46 as described above, and the arcuate engagement surface 44C of the left alignment member 44 protrudes from the left outer bracket 22B. By engaging with the protruding portion 24B of the left outer first bush 24, the left boom foot portion 9A is moved with respect to the hole axis AA of the left inner first bush 23 and the left outer first bush 24 provided on the left bracket 22. The hole axis of the provided left second bush 28 can be made coincident. Further, by engaging the arcuate engagement surface 46C of the right alignment member 46 with the protruding portion 27B of the right outer first bush 27 protruding from the right outer bracket 25B, the right inner first provided on the right bracket 25 is engaged. The hole axis of the right second bush 29 provided in the right boom foot portion 9B can be matched with the hole axis AA of the bush 26 and the right outer first bush 27.

  Thereby, the left connecting pin 30 can be easily inserted into the left inner first bush 23 of the left bracket 22, the left outer first bush 24, the left second bush 28 of the left boom foot portion 9A, and the right bracket. The right connecting pin 32 can be easily inserted into the right inner first bush 26, the right outer first bush 27, and the right second bush 29 of the right boom foot portion 9B, and the workability thereof can be improved.

  Next, FIGS. 14 and 15 show a third embodiment of the present invention. The feature of this embodiment is that the left and right alignment members are integrally fixed to the lower boom. It is to have done. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 51 denotes a two-member connecting device according to the third embodiment. The two-member connecting device 51 includes left and right brackets 22 and 25, left and right first pin insertion holes 22C and 25C, and a bottom. Left and right boom foot portions 9A and 9B, left and right second pin insertion holes 9C, left and right second bushes 28 and 29, left and right connecting pins 30 and 32, left and right described later Inner first bushes 52 and 54, left and right outer first bushes 53 and 55, left and right alignment members 56 and 57, and the like.

  A left inner first bush 52 is fitted into the left first pin insertion hole 22C of the left inner bracket 22A. The left inner first bush 52 has an axial dimension larger than the thickness dimension of the left inner bracket 22A. The insertion portion 52A is inserted into the left first pin insertion hole 22C, and the protrusion 52B protrudes leftward and rightward from the inner end surface 22A1 of the left inner bracket 22A.

  53 denotes a left outer first bush fitted into the left first pin insertion hole 22C of the left outer bracket 22B. The left outer first bush 53 has an axial dimension substantially equal to the thickness dimension of the left outer bracket 22B. Have.

  Reference numeral 54 denotes a right inner first bush fitted into the right first pin insertion hole 25C of the right inner bracket 25A. The right inner first bush 54 has an axial dimension larger than the thickness dimension of the right inner bracket 25A. The insertion portion 54A is inserted into the right first pin insertion hole 25C, and the protrusion 54B protrudes leftward and rightward from the inner end surface 25A1 of the right inner bracket 25A.

  55 denotes a right outer first bush fitted into the right first pin insertion hole 25C of the right outer bracket 25B. The right outer first bush 55 has an axial dimension substantially equal to the thickness dimension of the right outer bracket 25B. Have.

  Reference numeral 56 denotes a left centering member that is integrally fixed to the base end side of the lower boom 9, and this left centering member 56 is welded between the left and right boom foot portions 9A, 9B of the lower boom 9. The fixed plate portion 56A is fixed by using the above means, and the engaging plate portion 56B extends from the fixed plate portion 56A toward the second pin insertion hole 9C of the left boom foot portion 9A. Further, the engagement plate portion 56B is formed with an arcuate engagement surface 56C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 52B of the left inner first bushing 52. The left centering member 56 is integrally fixed to the lower boom 9 using means such as welding in a state where the center P of the arcuate engagement surface 56C is disposed on the hole axis of the left second bush 28. ing.

  57 is a right centering member that is integrally fixed to the base end side of the lower boom 9. This right centering member 57 is welded between the left and right boom foot portions 9A, 9B of the lower boom 9. The fixing plate portion 57A is fixed by using the above means, and the engaging plate portion 57B extends from the fixing plate portion 57A toward the second pin insertion hole 9C of the right boom foot portion 9B. Further, the engagement plate portion 57B is formed with an arcuate engagement surface 57C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 54B of the right inner first bush 54. The right centering member 57 is integrally fixed to the lower boom 9 by means of welding or the like with the center of the arcuate engagement surface 57C disposed on the hole axis of the right second bush 29. Yes.

  The two-member connecting device 51 according to the present embodiment has the above-described configuration, and the left inner first bush protruding from the inner end surface 22A1 of the left inner bracket 22A is the arcuate engagement surface 56C of the left centering member 56. 52 is engaged with the projecting portion 52B of the left second foot provided on the left boom foot portion 9A with respect to the hole axis AA of the left inner first bush 52 and the left outer first bush 53 provided on the left bracket 22. The hole axis of the bush 28 can be made coincident. Further, the arc-shaped engaging surface 57C of the right centering member 57 is provided on the right bracket 25 by engaging with the protruding portion 54B of the right inner first bush 54 protruding from the inner end surface 25A1 of the right inner bracket 25A. The hole axis of the right second bush 29 provided in the right boom foot portion 9B can be made to coincide with the hole axis AA of the right inner first bush 54 and the right outer first bush 55.

  In this case, the two-member connecting device 51 according to the present embodiment fixes the left and right alignment members 56 and 57 between the left and right boom foot portions 9A and 9B of the lower boom 9 by means such as welding. is doing. Thereby, the center of the arcuate engagement surface 56C of the left centering member 56 and the hole axis of the left second bush 28 can be made to coincide with each other accurately, and the center of the arcuate engagement surface 57C of the right centering member 57 And the hole axis of the right second bush 29 can be made to coincide with each other with high accuracy.

  As a result, the left connecting pin 30 can be easily inserted into the left inner first bush 52, the left outer first bush 53 of the left bracket 22, and the left second bush 28 of the left boom foot portion 9A. The right connecting pin 32 can be easily inserted into the right inner first bush 54, the right outer first bush 55, and the right second bush 29 of the right boom foot portion 9B, and the workability can be further enhanced.

  Next, FIGS. 16 and 17 show a fourth embodiment of the present invention. The feature of this embodiment is that a boom foot portion extending leftward and rightward is provided on the base end side of the lower boom, and this boom foot portion is shown. In other words, the left and right brackets are connected using a single connecting pin. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 61 denotes a two-member connecting device according to the fourth embodiment. The two-member connecting device 61 includes left and right brackets 62 and 64, left and right first pin insertion holes 62A and 64A, which will be described later. , Left and right first bushes 63 and 65, a boom foot portion 66A of the lower boom 66, a second pin insertion hole 67, left and right second bushes 68 and 69, a connecting pin 70, and left and right alignment members 74. 75, etc.

  62 is a left bracket integrally provided on the front side of a swivel frame (not shown) as a first member. The left bracket 62 is a left bracket standing on a bottom plate (not shown) of the swivel frame. It is comprised by the front-end part of a vertical board, and protrudes in the mountain shape toward the upper direction from the bottom board. A left first pin insertion hole 62A is provided on the upper end side of the left bracket 62 so as to penetrate in the left and right directions.

  63 denotes a left first bush fitted into the left first pin insertion hole 62A of the left bracket 62. The left first bush 63 is a cylindrical body having an axial dimension larger than the thickness dimension of the left bracket 62. Is formed. Here, the left first bush 63 is configured by an insertion portion 63A that is inserted into the left first pin insertion hole 62A, and a protrusion 63B that protrudes left and right from the left end surface 62B of the left bracket 62. Has been.

  64 is a right bracket integrally provided on the front side of a swivel frame (not shown) serving as a first member. The right bracket 64 is a right bracket standing on a bottom plate (not shown) of the swivel frame. It is composed of a front end portion of a vertical plate, and protrudes upward in a mountain shape while facing the left bracket 62 in the left and right directions. A right first pin insertion hole 64A is provided on the upper end side of the right bracket 64 so as to penetrate in the left and right directions.

  65 is a right first bush fitted into the right first pin insertion hole 64 </ b> A of the right bracket 64. The right first bush 65 is a cylindrical body having an axial dimension larger than the thickness dimension of the right bracket 64. Is formed. Here, the right first bush 65 includes an insertion portion 65A that is inserted into the right first pin insertion hole 64A, and a protruding portion 65B that protrudes left and right from the right end surface 64B of the right bracket 64. Has been.

  The left first bush 63 provided on the left bracket 62 side and the right first bush 65 provided on the right bracket 64 side are disposed on the same hole axis AA, and these left and right A connecting pin 70 described later is inserted into the inner peripheral side of the first bushes 63 and 65.

  Reference numeral 66 denotes a lower boom as a second member, and a boom foot portion 66A disposed between the left bracket 62 and the right bracket 64 is provided on the base end side of the lower boom 66. The boom foot portion 66A is The right brackets 62 and 64 are rotatably connected using a connecting pin 70 described later.

  Reference numeral 67 denotes a second pin insertion hole provided through the boom foot portion 66A of the lower boom 66 in the left and right directions. The second pin insertion hole 67 is a large-diameter hole located in the middle portion in the left and right directions. The portion 67A and left and right small-diameter holes 67B and 67C located on both the left and right sides with the large-diameter hole 67A interposed therebetween. A left second bush 68 described later is inserted into the left small diameter hole 67B, and a right second bush 69 described later is inserted into the right small diameter hole 67C.

  Reference numeral 68 denotes a left second bush fitted into the left small-diameter hole 67B constituting the second pin insertion hole 67 of the lower boom 66. The left second bush 68 is based on the axial dimension of the left small-diameter hole 67B. Is also formed as a cylinder having a slightly smaller axial dimension. The hole axis of the left second bush 68 is configured to match the hole axis AA of the left and right first bushes 63 and 65 provided in the left and right brackets 62 and 64.

  Reference numeral 69 denotes a right second bush inserted into a right small-diameter hole 67C constituting the second pin insertion hole 67 of the lower boom 66. The right second bush 69 is based on an axial dimension of the right small-diameter hole 67C. Is also formed as a cylinder having a slightly smaller axial dimension. The hole axis of the right second bush 69 is configured to coincide with the hole axis AA of the left and right first bushes 63 and 65 provided in the left and right brackets 62 and 64.

  Reference numeral 70 denotes a connecting pin that rotatably connects the left and right brackets 62 and 64 and the boom foot portion 66A of the lower boom 66. The connecting pin 70 is constituted by a single long pin, The bracket 62 is inserted into the left first bush 63 of the bracket 62, the left and right second bushes 68 and 69 of the boom foot portion 66A, and the right first bush 65 of the right bracket 64. In addition, a large-diameter flange portion 70A is fixed to one end side of the connection pin 70. By engaging this flange portion 70A with a stopper 71 provided on the right end surface 64B of the right bracket 64, the rotation of the connection pin 70 is stopped. It is the structure which performs and retaining.

  Reference numeral 72 denotes a left mounting seat provided on the left end surface 66B facing the left bracket 62 of the boom foot portion 66A of the lower boom 66. The left mounting seat 72 has an axial dimension larger than the thickness dimension of the left bracket 62. It is formed by the cylindrical body which has. The base end side of the left mounting seat 72 is fixed to the left end surface 66B of the boom foot portion 66A by means of welding or the like, and the left centering member 74 described later is fixed to the distal end side of the left mounting seat 72. It is the composition which becomes.

  73 is a right mounting seat provided on the right end surface 66C of the lower boom 66 that faces the right bracket 64 of the boom foot portion 66A, and the right mounting seat 73 has an axial dimension larger than the thickness dimension of the right bracket 64. It is formed by the cylindrical body which has. The base end side of the right mounting seat 73 is fixed to the right end surface 66C of the boom foot portion 66A by means of welding or the like, and a right alignment member 75 described later is fixed to the distal end side of the right mounting seat 73. It is the composition which becomes.

  Reference numeral 74 denotes a left centering member that is integrally fixed to the left end surface 66B of the boom foot portion 66A via the left mounting seat 72. The left centering member 74 is welded to the front end side of the left mounting seat 72. The fixed plate portion 74A is fixed by using the fixing plate portion 74A, and the engaging plate portion 74B extends from the fixed plate portion 74A toward the second pin insertion hole 67 of the boom foot portion 66A. Further, the engagement plate portion 74B is formed with an arcuate engagement surface 74C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 63B of the left first bush 63. The left centering member 74 is integrally fixed to the left mounting seat 72 in a state where the center P of the arcuate engagement surface 74C is disposed on the hole axis of the left and right second bushes 68 and 69. Yes.

  Reference numeral 75 denotes a right centering member that is integrally fixed to the right end surface 66C of the boom foot portion 66A via the right mounting seat 73. The right centering member 75 is welded or the like on the distal end side of the right mounting seat 73. The fixed plate portion 75A is fixed to the second plate insertion hole 67 of the boom foot portion 66A from the fixed plate portion 75A. In addition, the engagement plate portion 75B is formed with an arcuate engagement surface 75C that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion 65B of the right first bush 65. The right centering member 75 is integrally fixed to the right mounting seat 73 in a state where the center of the arcuate engagement surface 75C is disposed on the hole axis of the left and right second bushes 68 and 69. .

  The two-member connecting device 61 according to the present embodiment has the above-described configuration, and the left first bushing 63 projecting from the left end surface 62B of the left bracket 62 is formed on the arcuate engagement surface 74C of the left centering member 74. By engaging with the protrusion 63B and engaging the arcuate engagement surface 75C of the right centering member 75 with the protrusion 65B of the right first bushing 65 protruding from the right end surface 64B of the right bracket 64, the left, The hole axial lines AA of the left and right first bushes 63 and 65 provided on the right brackets 62 and 64 are aligned with the hole axial lines of the left and right second bushes 68 and 69 provided on the boom foot portion 66A. be able to.

  As a result, the connecting pin 70 can be easily inserted into the left first bush 63 of the left bracket 62, the left and right second bushes 68 and 69 of the boom foot portion 66A, and the right first bush 65 of the right bracket 64. The workability when the left and right brackets 62 and 64 and the boom foot 66A of the lower boom 66 are connected by the connecting pin 70 can be improved.

  In the first embodiment described above, the left and right boom foot portions 9A and 9B of the lower boom 9 are connected to the left and right brackets 22 and 25 using the left and right connection pins 30 and 32, respectively. The case where the left and right alignment members 35 and 37 are attached to the left and right attachment seats 33 and 34 will be exemplified later. However, the present invention is not limited to this, and after the left and right boom foot portions 9A and 9B are connected to the left and right brackets 22 and 25, the left and right alignment members 35 and 37 are connected to the left and right You may remove from the mounting seats 33 and 34. FIG. The same applies to the left and right alignment members 44 and 46 according to the second embodiment.

  In the first embodiment described above, the two-member connecting device 21 is used as a connecting portion between the turning frame 4 constituting the upper turning body 3 of the excavator 1 and the lower boom 9 constituting the work device 8. This is an example. However, the present invention is not limited to this. For example, the present invention can also be applied to a connection portion between the lower boom 9 and the joint boom 10 constituting the work device 8, a connection portion between the joint boom 10 and the upper boom 11, and the like. . The same applies to the second, third, and fourth embodiments.

4 Rotating frame (first member)
9,66 Lower boom (second member)
9A Left boom foot part 9B Right boom foot part 9A1, 62B Left end face 9B1, 64B Right end face 9C, 67 Second pin insertion hole 21, 41, 51, 61 Two-member connecting device 22, 62 Left bracket 22C, 62A Left first pin insertion Hole 23,52 Left inner first bush (Left first bush)
24, 53 Left outer first bush (Left first bush)
24A, 27A, 52A, 54A, 63A, 65A Insertion part 24B, 27B, 52B, 54B, 63B, 65B Protrusion part 25, 64 Right bracket 25C, 64A Right first pin insertion hole 26, 54 Right inner first bush ( Right first bush)
27,55 Right outer first bush (right first bush)
28, 68 Left second bush (second bush)
29,69 Right second bush (second bush)
30 Left connection pin (connection pin)
32 Right connection pin (connection pin)
35, 44, 56, 74 Left alignment member 35D, 37C, 44C, 46C, 56C, 57C, 74C, 75C Arc-shaped engagement surface 37, 46, 57, 75 Right alignment member 63 Left first bush 65 Right first 1 bush 70 connecting pin

Claims (4)

A first member having left and right brackets provided facing each other in the left and right directions; a left and right first pin insertion hole provided in each of the left and right brackets of the first member; Cylindrical left and right first bushes respectively fitted into the left and right first pin insertion holes, a second member removably connected to the first member, and the second member A second pin insertion hole provided, a cylindrical second bushing inserted in the second pin insertion hole and disposed on the same hole axis as the left and right first bushes, and the left and right In the two-member coupling device formed by a coupling pin that is fitted on the inner peripheral side of the first bush and the inner peripheral side of the second bush and connects the first member and the second member.
The left and right first bushes include an insertion part that is inserted into the left and right first pin insertion holes, and a protrusion part that protrudes left and right from the end surface position of the left and right brackets. Formed as a single cylinder consisting of
The hole axis of the second bush coincides with the hole axis of the left and right first bushes by engaging the second member with the protrusions of the left and right first bushes from the outer peripheral side. A two-member connecting device characterized in that a centering member is provided.   The centering members are respectively disposed in portions of the second member facing the end surfaces of the left and right brackets in the left and right directions, and the left and right centering members are the left and right centers. The two-member connecting device according to claim 1, wherein the two-member connecting device is configured to simultaneously engage with the protruding portion of the first bush.   The alignment member has an arcuate engagement surface that is curved in an arc shape with a radius substantially equal to the outer peripheral surface of the protruding portion of the left and right first bushes, and the center of the arcuate engagement surface is the center of the arcuate engagement surface. The two-member coupling device according to claim 1 or 2, wherein the two-member coupling device is configured to be disposed on the same axis as the hole axis of the two bushes.   4. The two-member connecting device according to claim 1, wherein the centering member is configured to be provided integrally or detachably with respect to the second member.

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