JP2019112183A - Handrail of working machine - Google Patents

Abstract

To provide a handrail provided to a body of a working machine, the handrail comprising a handrail body that is easily mounted, and preventing rattling of the handrail body after it is mounted.SOLUTION: A handrail has a handrail body and a pair of frame coupling parts 210. A pair of handrail coupling parts 55 of the handrail body each has a pair of front and back handrail side-tabular parts 550, an engagement pin 551, and a first hole part. The pair of frame coupling parts 210 each has a frame side-tabular part 210A, an engagement concave part 211, and a second hole part 212. Even when an outer diameter of the engagement pin 551 varies within tolerance, an outer periphery of the engagement pin 551 stably abuts on an inclined surface 211A by dead weight of the handrail body, preventing rattling of the handrail body. Moreover, a coupling pin 60 is easily mounted on the first hole part and the second hole part 212 which is formed into a long-hole shape, each of the first hole part and the second hole part 212 being opened in the pair of handrail side-tabular parts 550.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a handrail provided to a working machine.

  Work machines such as cranes and shovels generally include an airframe and a work attachment supported on the airframe so as to be able to be raised and lowered. Workers sometimes move on the aircraft when boarding a cockpit arranged on the aircraft or when disassembling work of a working machine.

  Patent Document 1 discloses a working machine provided with a step and a handrail arranged around a cockpit. The operator moves the steps while gripping the handrail body of the handrail and enters the boarding room.

  2. Description of the Related Art Conventionally, as a handrail as described above, a handrail including a handrail main body that is detachable from an airframe and a pair of airframe connecting portions fixed to the airframe is known. The handrail main body has a gripped portion gripped by a worker and a pair of handrail connecting portions respectively connected to the pair of machine body connecting portions.

JP 2003-192272 A

  The conventional handrail as described above has a problem that the handrail main body is easily rattled after the handrail main body is fixed to the airframe. Specifically, FIG. 11 is a cross-sectional view showing how the handrail connecting portion and the machine body connecting portion of the conventional handrail as described above are connected to each other. The handrail connection portion 55Z has a handrail side plate-like portion 550Z, and an engagement pin 551Z which is provided so as to protrude from the handrail side plate-like portion 550Z. On the other hand, a U-shaped engaging recess 211Z and a circular second hole 212Z are formed in an airframe connecting portion 210Z provided in the airframe. A first hole (not shown) similar to the second hole 212Z is also opened in the handrail side plate-like portion 550Z.

  When the worker fixes the handrail main body to the machine body, the handrail connection portion 55Z of FIG. 11 is attached to the machine body connection portion 210Z from above. At this time, when the engagement pin 551Z is inserted into the engagement recess 211Z, the first hole portion (not shown) formed in the handrail side plate portion 550Z and the second hole portion 212Z formed in the body connecting portion 210Z The handrail main body is fixed to the airframe by matching and inserting the connecting pin 60Z into both.

  In the conventional configuration as shown in FIG. 11, even if the outer diameter of the engagement pin 551Z is the manufacturing tolerance upper limit value, the outer diameter of the engagement pin 551Z so that the engagement pin 551Z fits into the engagement recess 211Z. The dimensions and the opening width of the engagement recess 211Z need to be set. However, in this case, if the outer diameter of the engagement pin 551Z is the lower limit of tolerance, a large gap (backlash) is generated between the engagement pin 551Z and the engagement recess 211Z. As a result, even after the handrail main body is fixed to the airframe, the handrail connecting portion 55Z easily swings in the arrow DR direction of FIG. 11 with the connecting pin 60Z as a fulcrum, and there is a problem that the handrail main body rattles. Also, in order to eliminate such rattling, a method is conceivable in which the engagement pin 551Z is fixed to the engagement recess 211Z by welding after connection, but in this case, the connection operation time and cost increase and Is difficult to remove from the machine.

  Furthermore, when a pair of handrail connection parts 55Z as shown in FIG. 11 is disposed across a predetermined gripped part, and a pair of machine body connection parts 210Z is disposed on the body opposite to the pair of handrail connection parts 55Z. (See Figure 2). In this case, the tolerance (shape accuracy) of the handrail as a whole is also important. That is, when the gripped portion is twisted, or one end side and the other end side of the gripped portion may be shifted in the vertical direction. As a result, even if one handrail connection portion 55Z is inserted into the airframe connection portion 210Z, it becomes difficult for the other handrail connection portion 55Z to be inserted into the airframe connection portion 210Z. In particular, when the gripped portion is twisted, in the other handrail connection portion 55Z, the engagement pin 551Z is separated from the engagement recess 211Z, which makes insertion difficult. In addition, when the gripped portion is shifted up and down, the other engagement pin 551Z does not reach the engagement recess 211Z in the up and down direction, which makes insertion difficult. The overall tolerances that occur in such handrails are due to the accumulation of errors and tolerances in the assembly stages of the components. In addition, when welding is included in the assembly, distortion due to welding is also a cause.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a handrail provided on an airframe of a working machine, in which the handrail body is easily attached and the backlash of the handrail body after attachment is suppressed. Do.

  A handrail provided on an airframe of a working machine according to one aspect of the present invention, which is disposed at an interval in a horizontal first direction below a grasped portion grasped by an operator and the grasped portion A handrail main body having a pair of handrail connection portions, and a pair fixed to the machine body so as to be disposed at an interval in the first direction, and allowing the pair of handrail connection portions to be connected respectively And a pair of connection pins respectively connecting the pair of handrail connection portions and the pair of body connection portions, one of the pair of handrail connection portions and the pair of body connection portions The pair of connecting portions are disposed orthogonal to the first direction, and extend in the first direction between the pair of first members facing each other in the first direction and the pair of first members. Outer peripheral surface And having a connection portion connecting the pair of first members to each other, and the pair of first members of the one pair of connection portions are vertically spaced from the connection portion A pair of first holes which are arranged opposite to each other in the first direction and into which the connection pin can be inserted are formed at the respective positions, and the pair of handrail connection portions and the pair of body connection portions The other pair of connecting portions has an upper end portion and a lower end portion, and is disposed orthogonal to the first direction, and along with the connection between the handrail connecting portion and the body connecting portion, the pair of first members , And the second members are disposed opposite to each other in a second direction orthogonal to the first direction and the vertical direction, respectively, Said connection part in connection with part It has a pair of restraint surfaces arranged so as to sandwich the space part received along the vertical direction from both sides of the second direction, and the pair of restraint surfaces is along the approach direction of the connection part to the space part The connecting portions are inclined in the downward direction and the second direction by being in contact with the outer peripheral surface of the connection portion by the weight of the handrail main body by being inclined so as to narrow the distance between each other. A second position in which the connection pin can be inserted at a position vertically spaced from the pair of constraining surfaces of the two members and at positions facing the pair of first holes in the first direction. A hole is formed, and the opening width in the vertical direction of the pair of first holes and the second hole is such that the second hole includes the pair of first holes in the vertical direction. Is set .

  According to this configuration, even when the outer diameter of the connection portion varies within the tolerance, the connection portion can stably contact the restraint surface by the weight of the handrail body. Therefore, the handrail body can be restrained in the downward direction and the second direction. Furthermore, since the second member is disposed between the pair of first members, the handrail body can be restrained also in the first direction. As a result, it is possible to suppress rattling of the handrail body after mounting. In addition, even if there is an individual difference in the relative position of the first member and the second member in the vertical direction according to the outer diameter of the connection portion, the connecting pin is in the pair of first hole and second hole It can be easily installed.

  In the above configuration, when viewed in a cross section orthogonal to the first direction, the outer peripheral surface of the connection portion includes a pair of contact portions each formed of a convex curve toward the pair of constraining surfaces, The pair of constraining surfaces may be a pair of straight lines or a pair of concave curves toward the pair of contact portions, and the contact portions may contact the constraining surfaces along the first direction. It is desirable that the radius of curvature of the contact portion be set smaller than the radius of curvature of the constraining surface.

  According to this configuration, even when the outer diameter of the connection portion varies within the tolerance, the connection portion can stably contact the restraint surface by the weight of the handrail body.

  In the above configuration, when viewed in a cross section orthogonal to the first direction, the pair of constraining surfaces and the pair of contact portions are line symmetrical in the second direction centering on a center line along the vertical direction. Preferably, the pair of first holes and the second holes are arranged on the center line.

  According to this configuration, when the connecting portion abuts on the pair of constraining surfaces, the first hole and the second hole are arranged on the predetermined center line. As a result, the worker can easily insert the connection pin into the first hole and the second hole.

  In the above configuration, when viewed in a cross section orthogonal to the first direction, it is preferable that the outer peripheral surface of the connection portion has a circular shape including the pair of contact portions.

  According to this configuration, when the connecting portion has a simple cylindrical shape, the connecting portion and the pair of constraining surfaces can stably contact each other even if the outer diameter of the connecting portion varies within the tolerance.

  In the above configuration, the second member has an inner peripheral surface that defines the second hole, and the inner peripheral surface abuts on the connection pin inserted into the first hole. It is desirable that an opening width in the second direction of the second hole is set so that rotation of the handrail main body with respect to the part is restricted.

  According to this configuration, the connection pin is inserted into the pair of first and second hole portions, so that the handrail body is prevented from rotating (rotation prevention).

  In the above configuration, the one pair of connecting parts may be the pair of handrail connecting parts, and the other one of the pair of connecting parts may be the pair of body connecting parts.

  According to this configuration, the worker can easily attach the handrail main body to the pair of machine body connecting portions. In particular, when assembling the handrail main body to the airframe, it is easy to confirm that the connection portion of the handrail connection portion is inserted from above into the space portion between the pair of restraint surfaces disposed in the airframe connection portion. For this reason, the worker can attach the handrail body easily and reliably.

  According to the present invention, it is possible to provide a handrail provided on the body of a working machine in which the mounting of the handrail main body is easy and the backlash of the handrail main body after mounting is suppressed.

It is a side view of a work machine concerning one embodiment of the present invention. FIG. 2 is an exploded perspective view of an airframe and a handrail of a working machine according to an embodiment of the present invention. It is a disassembled side view of the fuselage and handrail of the working machine concerning one embodiment of the present invention. It is a perspective view of a fuselage and a handrail of a work machine concerning one embodiment of the present invention. It is a side view of a fuselage and a handrail of a work machine concerning one embodiment of the present invention. It is sectional drawing of the handrail connection part of the handrail which concerns on one Embodiment of this invention, a vehicle body connection part, and a connection pin. FIG. 7 is a side sectional view of the handrail connection portion, the vehicle body connection portion and the connection pin of FIG. It is sectional drawing of the handrail connection part of the handrail which concerns on one Embodiment of this invention, a vehicle body connection part, and a connection pin. It is a sectional side view of the handrail connection part of FIG. 8, an airframe connection part, and a connection pin. It is sectional drawing of the handrail connection part of the handrail which concerns on the modified embodiment of this invention, a vehicle body connection part, and a connection pin. It is sectional drawing of the handrail connection part of the conventional handrail, a vehicle body connection part, and a connection pin.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a crane (construction machine) according to the present embodiment. In addition, although the direction of "upper", "lower", "front", and "rear" is shown in FIG. 1, the said direction shows for convenience in order to demonstrate the structure of the crane 1 which concerns on this embodiment. It is shown and the usage mode etc. of the working machine which concerns on this invention are not limited. The crane includes an undercarriage 1 capable of traveling on the ground, an upper revolving superstructure 2 (airframe) disposed above the undercarriage 1, and a boom 3 as a relief member. The upper swing body 2 is mounted on the lower traveling body 1 so as to be swingable around a swing center CL extending in the vertical direction. The upper swing body 2 includes a swing frame 21 as a base, a cab 22 and a guard 23. The cab 22 is provided at the front end of the upper swing body 2 and corresponds to the driver's seat of the crane. The guard 23 accommodates therein a boom hoisting winch 10 and a hoist drum 15, which will be described later, and an engine (not shown).

  The boom 3 is supported by the swing frame 21 of the upper swing body 2 so as to be able to move up and down around a horizontal axis. The crane includes a gantry 4, a counterweight 5, a boom guy line 6, an upper spreader 7, a lower spreader 8, a boom undulation rope 9, a boom undulation winch 10, a boom point sheave 11 and an idler sheave 12; It further comprises a hook 13, a winding rope 14 and a winding drum 15.

  The gantry 4 is mounted at the rear of the swing frame 21 of the upper swing body 2. Specifically, the gantry 4 is supported by the pivot frame 21 behind the boom 3 and functions as a support for supporting the boom 3 in the raising and lowering movement of the boom 3. The counterweight 5 is attached to the swing frame 21 at the rear of the gantry 4 and has a function of maintaining the balance of the crane when the crane lifts the suspended load.

  The upper spreader 7 and the lower spreader 8 each comprise a plurality of sheaves. Further, the upper spreader 7 is connected to the tip of the boom 3 by the boom guy line 6. The boom undulation rope 9 is pulled out from the boom undulation winch 10 and hung on a sheave at the end of the gantry 4 and then hung around a plurality of times between the lower spreader 8 and the upper spreader 7. The boom hoisting winch 10 is fixed to the rear of the pivot frame 21. The tip of the boom relief rope 9 pulled out is fixed to the gantry 4. The boom undulation winch 10 changes the distance between the upper spreader 7 and the lower spreader 8 by winding and unwinding the boom undulation rope 9 and rotates the boom 3 relative to the gantry 4. While raising the boom 13.

  The winding drum 15 is fixed at the center of the swing frame 21. Also, the boom point sheave 11 and the idler sheave 12 are rotatably supported at the tip of the boom 3. A hook 13 for hanging is provided at the tip of the winding rope 14 pulled out of the winding drum 15. Then, one end of the hoisting rope 14 is wound around the boom point sheave 11 at the tip of the boom 3 and the sheave of the sheave block (not shown) provided on the hook 13, It is fixed. On the other hand, the other end of the winding rope 14 is wound around the winding drum 15 via the boom point sheave 11 and the idler sheave 12. Therefore, when the winding drum 15 winds up or unwinds the winding rope 14, the distance between the boom point sheave 11 and the sheave of the hook 13 changes, and the winding of the hook 13 suspended from the tip of the boom 3 A lowering is performed.

  FIG. 2 is an exploded perspective view of the swing frame 21 (body) and the handrail 50 of the crane according to the present embodiment, and FIG. 3 is an exploded side view of the same. 4 is a perspective view of the swing frame 21 (body) and the handrail 50, and FIG. 3 is a side view of the same. 2 and 3 show how the handrail main body 51 of the handrail 50 is attached to the turning frame 21. FIGS. 4 and 5 show how the handrail 50 is attached to the turning frame 21. As shown in FIG. 6 is a cross-sectional view of the handrail connecting portion 55, the frame connecting portion 210 (body connecting portion) and the connecting pin 60 of the handrail 50 according to the present embodiment, and FIG. 7 is a handrail connecting portion 55 of FIG. FIG. 6 is a side cross-sectional view of a frame connection portion 210 and a connection pin 60.

  Referring to FIGS. 2 to 7, the crane according to the present embodiment includes at least one handrail 50. The handrail 50 is provided on the swing frame 21 of the upper swing body 2 and protects the worker moving on the upper swing body 2 and assists the movement of the worker. The swing frame 21 has a frame upper surface portion 21H and a frame side surface portion 21S (FIG. 2). The frame upper surface portion 21 H is an upper surface portion of the turning frame 21, and the frame side surface portion 21 S is a side surface portion of the turning frame 21. In FIG. 2, the frame side portion 21S defines the right side of the pivoting frame 21. On the other hand, the handrail 50 has a handrail main body 51, a pair of frame connection parts 210, and a pair of connection pins 60 (FIG. 6).

  The handrail main body 51 is detachable from the turning frame 21. The handrail main body 51 has a gripped portion 511, a pair of vertical frames 512, a horizontal frame 52, a connection frame 53, a pair of ribs 54, and a pair of handrail connection portions 55 (FIG. 2). In addition, as an example, the weight of the handrail main body 51 is set to 15 kg-20 kg.

  The to-be-held part 511 is arrange | positioned at the upper end part of the handrail main body 51, and consists of a pipe extended in the front-back direction. The gripped portion 511 is gripped by the worker. The pair of vertical frames 512 are connected to the front and rear end portions of the gripped portion 511 and are pipes extending in the vertical direction. In the present embodiment, the gripped portion 511 and the pair of vertical frames 512 are integrally configured, and are configured by bending a single pipe material. As shown in FIG. 3, the lower end portion of the vertical frame 512 has a shape which is slightly bent so as to extend obliquely leftward and downward and then slightly bent so as to extend downward again. . The horizontal frame 52 is a pipe that connects the pair of vertical frames 512 at a substantially central portion in the vertical direction of the handrail main body 51. The pair of ribs 54 is fixed to the lower portion of the pair of vertical frames 512, respectively. The rib 54 has a function of enhancing the rigidity of the vertical frame 512 (handrail main body 51). The connection frame 53 is disposed at a lower portion of the horizontal frame 52 and connects the pair of ribs 54 to each other. The connection frame 53 is formed of a plate-like member, and a plurality of openings are formed in the plate-like member as shown in FIG.

  The pair of handrail connection portions 55 is fixed to the left side portion of the lower end portion of the pair of vertical frames 512. The pair of handrail connection portions 55 are disposed below the held portion 511 at intervals in the front-rear direction (horizontal first direction). Further, although not shown in FIGS. 2 and 3, the pair of handrail connection portions 55 includes a pair of plate-like members arranged at intervals in the front-rear direction (a handrail side plate-like portion 550 of FIG. reference).

  As shown in FIG. 2, the pair of frame connecting portions 210 is fixed to the frame side surface portion 21S of the turning frame 21 so as to be spaced apart in the front-rear direction. The pair of frame connection portions 210 allow the pair of handrail connection portions 55 to be connected to each other.

  The pair of connection pins 60 (FIG. 6, FIG. 7) respectively connect the pair of handrail connection portions 55 and the pair of frame connection portions 210.

  Next, the connection structure of the pair of handrail connection parts 55 and the pair of frame connection parts 210 will be described in more detail. In the present embodiment, the pair of handrail connecting portions 55 form one pair of connecting portions of the present invention, and the pair of frame connecting portions 210 form the other pair of connecting portions of the present invention.

  In addition, since the pair of front and rear handrail connection parts 55 have the same structure and function as each other and the pair of front and rear frame connection parts 210 have the same structure and function as each other, the front side handrail connection part 55 and the frame The connecting unit 210 will be described.

  The handrail connection portion 55 includes a pair of handrail side plate-like portions 550 (first members) and an engagement pin 551 (connection portion) (FIG. 6, FIG. 7). The pair of handrail side plate-like portions 550 are disposed to be orthogonal to the front-rear direction, and are disposed to face each other in the front-rear direction. As shown in FIG. 2 and FIG. 6, the handrail side plate-like portion 550 has a trapezoidal shape and has a predetermined thickness in the front-rear direction.

  The engagement pin 551 has a cylindrical shape having an outer peripheral surface extending in the front-rear direction between the pair of handrail side plate-like portions 550. The engagement pin 551 connects the pair of handrail side plate-like portions 550 with each other in the front-rear direction. In the present embodiment, both ends of the engagement pin 551 are arc-welded to the pair of handrail side plate-like portions 550, respectively.

  As shown in FIG. 7, first holes 552 are respectively formed in the pair of handrail side plate-like portions 550. The first hole 552 has a circular shape, and penetrates the handrail side plate-like portion 550 in the front-rear direction at a position spaced downward from the engagement pin 551. The first holes 552 formed in the pair of handrail side plate-like portions 550 are arranged to face each other in the front-rear direction. Further, the inner diameter of the first hole 552 is set to a value slightly larger than the outer diameter of the connection pin 60. For this reason, the connection pin 60 is insertable into the first hole 552.

  The frame connection portion 210 has a frame side plate-like portion 210A (second member) (FIG. 6). The frame side plate-like portion 210A is disposed to be orthogonal to the front-rear direction (first direction), and has a substantially rectangular shape extending in the vertical and horizontal directions as shown in FIG. The frame side plate-like portion 210A has an upper end 210B and a lower end. The frame side plate-like portion 210A is disposed between the pair of handrail side plate-like portions 550 along with the connection of the handrail connecting portion 55 and the machine body connecting portion 210. In the frame side plate-like portion 210A, an engaging recess 211 (space portion) and a second hole 212 are formed. The engagement recess 211 is a recess formed in the upper end portion 210B of the frame side plate-like portion 210A. The engagement recess 211 receives the engagement pin 551 along the vertical direction (in particular, the lower direction) along with the connection between the handrail connection portion 55 and the frame connection portion 210. As shown in FIG. 6, the engagement recess 211 has a substantially V shape. Specifically, the engagement recess 211 is defined by the pair of inclined surfaces 211A (restraint surface) and the recess lower end portion 211B.

  The pair of inclined surfaces 211A are disposed to be opposite to each other at an interval in the left-right direction (the second direction orthogonal to the first direction and the vertical direction). The pair of inclined surfaces 211A is disposed so as to sandwich the space portion in which the engagement pin 551 enters in the vertical direction from both sides in the left-right direction. Further, the pair of inclined surfaces 211A are inclined such that the distance between the pair of inclined surfaces 211A is narrow along the advancing direction (downward direction) of the engagement pin 551 with respect to the engagement recess 211. Then, the pair of inclined surfaces 211A restrains the engagement pin 551 in the downward direction and the left and right direction by allowing the outer peripheral surface of the engagement pin 551 to abut by the weight of the handrail main body.

  The recess lower end portion 211 </ b> B connects the lower ends of the pair of engagement recesses 211. The recess lower end portion 211B has a circular arc shape which is convex downward. The radius of curvature of the recess lower end portion 211 </ b> B is set to be the same as the radius of curvature of the engagement pin 551 or smaller than the radius of curvature of the engagement pin 551.

  The second hole portion 212 is formed in the frame side plate-like portion 210A at a position spaced below the engagement concave portion 211 (a pair of inclined surfaces 211A). Further, the second hole portion 212 is formed in the frame side plate-like portion 210A so as to face the pair of first hole portions 552 in the front-rear direction. As shown in FIGS. 6 and 7, the second hole 212 has an elongated hole shape extending in the vertical direction. The opening width of the second hole 212 in the left-right direction is set to a value slightly larger than the outer diameter of the connection pin 60. Further, the opening width of the second hole 212 in the vertical direction is larger than the opening width of the pair of first holes 552 in the vertical direction, and is set to twice the outer diameter of the connection pin 60. That is, the opening widths of the pair of first hole 552 and the second hole 212 in the vertical direction are set such that the second hole 212 includes the pair of first holes 552 in the vertical direction. More specifically, the frame side plate-like portion 210A has an inner circumferential surface that defines the second hole 212. Then, the connection pin 60 inserted into the first hole 552 abuts on the inner peripheral surface, so that the rotation of the handrail main body with the engagement pin 551 as a fulcrum is restricted in the second hole 212. The opening width in the left and right direction is set.

  6 and 7 show the connected state of the handrail connecting portion 55 and the frame connecting portion 210 when the outer diameter D1 (FIG. 6) of the engaging pin 551 is the lower limit value of the preset tolerance. There is. As shown in FIGS. 2 and 3, when the worker fixes the handrail 50 to the turning frame 21, the pair of handrail connecting portions 55 are attached to the pair of frame connecting portions 210 from above. Under the present circumstances, in each handrail connection part 55, the engagement pin 551 arrange | positioned between a pair of handrail side plate-like parts 550 approachs into the engagement recessed part 211 opened by the flame | frame connection part 210 from upper direction. Eventually, as shown in FIG. 6, the outer peripheral surface of the cylindrical engaging pin 551 abuts on the pair of inclined surfaces 211A at the abutting position P1. At this time, as shown in FIG. 6, a predetermined gap is formed between the lower end portion of the engagement pin 551 and the recess lower end portion 211B. When the engagement pin 551 abuts on the pair of inclined surfaces 211A, the handrail main body 51 is restrained in the lower direction and the left and right direction. As described above, in the present embodiment, since the weight of the handrail main body 51 is 15 kg to 20 kg, even if the operator releases the hand from the handrail 50, the engagement pins 551 are inclined by the weight of the handrail main body 51. The state of contact with the surface 211A is maintained.

  When the engagement pin 551 abuts on the pair of inclined surfaces 211A, the second hole 212 is disposed between the pair of first holes 552, as shown in FIG. Then, the worker inserts the connection pin 60 in the order of the rear first hole 552, the second hole 212, and the front engagement pin 551 so that the handrail connection 55 and the frame connection 210 are mutually connected. It is fixed. As a result, the handrail side plate-like portion 550 is restrained also in the vertical direction with respect to the frame side plate-like portion 210A. A retaining pin (not shown) is attached to the tip of the connection pin 60 which penetrates the front first hole 552. The reference line L1 shown in FIGS. 6 and 7 indicates the lower end portion of the engagement pin 551 having the outer diameter D1, and the reference line L2 indicates the lower end portion of the pin main portion of the connecting pin 60. There is.

  8 is a cross-sectional view of the handrail connecting portion 55, the frame connecting portion 210 and the connecting pin 60 of the handrail 50 according to the present embodiment, and FIG. 9 is a handrail connecting portion 55, the frame connecting portion 210 and FIG. FIG. 5 is a side cross-sectional view of a connection pin 60. 8 and 9 show the handrail connecting portion 55 in the case where the outer diameter D2 (FIG. 8) of the engagement pin 551 is the upper limit value of the preset tolerance, as compared with FIG. 6 and FIG. And the frame connection part 210 are shown.

  Also in FIG. 8 and FIG. 9, the pair of handrail connection parts 55 are attached to the pair of frame connection parts 210 from above by the operator as in FIG. 6 and FIG. 7. And in each handrail connection part 55, the engagement pin 551 arrange | positioned between a pair of handrail side plate-like-parts 550 enters into the engagement recessed part 211 opened by the flame | frame connection part 210 from upper direction. Eventually, as shown in FIG. 8, the outer peripheral surface of the cylindrical engagement pin 551 abuts on the pair of inclined surfaces 211A at the abutting position P2. At this time, the contact position P2 is positioned above the contact position P1 (FIG. 6) by the height h. The reference line L3 shown in FIGS. 8 and 9 indicates the lower end portion of the engagement pin 551 having the outer diameter D2, and the reference line L4 indicates the lower end portion of the pin main portion of the connecting pin 60. There is. That is, the reference line L3 is positioned above the reference line L1 by the height h, and the reference line L4 is positioned above the reference line L2 by the height h (FIG. 8).

  In the present embodiment, as described above, the second hole 212 has an elongated hole shape extending in the vertical direction. For this reason, as shown in FIGS. 8 and 9, even when the relative mounting position of the handrail side plate-like portion 550 with respect to the frame connection portion 210 is positioned higher than in FIGS. The second hole 212 is disposed between the first holes 552. More specifically, the lower end of the second hole 212 is disposed below the lower end of the pair of first holes 552. Therefore, as shown in FIG. 9, the worker can easily insert the connection pin 60 in the order of the rear first hole 552, the second hole 212, and the front engagement pin 551. In FIG. 9, the upper end of the second hole 212 may be disposed above the upper ends of the pair of first holes 552. As a result, regardless of the relative position of the frame-side plate-like portion 210A in the vertical direction with respect to the handrail-side plate-like portion 550 according to the outer diameter of the engagement pin 551, the connecting pin 60 has a pair of first holes 552. It can be inserted in order along the front-back direction with respect to the other 1st hole of the 1st 1st hole, the 2nd hole 212, and a pair of 1st holes 552.

  In other words, in the present embodiment, the handrail side plate-like portion 550 and the frame side plate-like portion 210A according to the contact position (P1, P2) between the outer peripheral surface of the engagement pin 551 and the pair of inclined surfaces 211A. And the relative positional relationship between them in the vertical direction is restricted. Then, the connection pin 60 is inserted into the pair of first hole 552 and the second hole 212 in a state where the positional relationship is restricted, so that the handrail main body 51 is prevented from coming off, and the engagement pin 551 The pivoting of the handrail main body 51 around the pivot point is prevented. At this time, even if the contact position changes due to the outer diameter tolerance of the engagement pin 551, the second hole 212 is maintained to be positioned between the pair of first holes 552 In addition, the second hole portion 212 is formed in the shape of a long hole along the vertical direction.

  According to such a configuration, even if the outer diameter of the engagement pin 551 varies within the tolerance, the engagement pin 551 can stably abut on the pair of inclined surfaces 211A by the weight of the handrail 50, respectively. In particular, since the engagement recess 211 is defined by the pair of inclined surfaces 211A, the engagement position between the engagement pin 551 and the engagement recess 211 is adjusted according to the actual outer diameter of the engagement pin 551. As a result, since the handrail 50 is restrained in the lower direction and the left and right direction, rattling of the handrail 50 is suppressed. Further, in the present embodiment, since the frame connection portion 210 is disposed between the pair of handrail side plate members 550, the handrail side plate member 550 is also restrained in the front-rear direction, and rattling of the handrail 50 is further suppressed. In addition, when it sees in the cross section shown in FIG. 6, the part (contact part) contact | abutted on a pair of inclined surface 211A among the engagement pins 551 consists of a convex-shaped curve toward a pair of inclined surfaces 211A, respectively. On the other hand, the pair of inclined surfaces 211A may be formed of a pair of concave curves toward a pair of flat surfaces or a pair of curves of the engagement pin 551 as in the present embodiment. In any case, the pair of contact portions of the engagement pin 551 are in line contact (contact) with the pair of inclined surfaces 211A along the front-rear direction. It is desirable that the radius of curvature of is set smaller than the radius of curvature of the pair of inclined surfaces 211A. In this case, even if the outer diameter of the engagement pin 551 varies within the tolerance, the engagement pin 551 can stably contact the pair of inclined surfaces 211A by the weight of the handrail body 51. Further, in the present embodiment, since the engaging pin 551 has a simple cylindrical shape, the engaging pin 551 and the pair of inclined surfaces 211A are stable even if the outer diameter of the engaging pin 551 varies within the tolerance. It can abut. Furthermore, in the present embodiment, the cross sections of the pair of inclined surfaces 211A and the engagement pin 551 are line symmetrical in the left-right direction with respect to the center line CL along the up-down direction. On the other hand, the centers of the first hole 552 and the second hole 212 are also arranged on the center line CL. Therefore, when the engagement pin 551 abuts on the pair of inclined surfaces 211A, the first hole and the second hole are disposed on the predetermined center line CL. As a result, the worker can easily insert the connection pin 60 into the first hole and the second hole.

  Further, in the present embodiment, as described above, even if the relative position in the vertical direction of the handrail side plate-like portion 550 and the frame side plate-like portion 210A varies, the second hole portion 212 has an elongated hole shape. The connecting pin 60 can be easily attached to the pair of first holes 552 and the second holes 212.

  The difference in outer diameter of the engagement pin 551 is not limited to the difference in tolerance. In the case where the handrail connection portion 55 is subjected to anticorrosion treatment (including base coating, top coating, hot dip galvanization, and the like), the outer diameter of the engagement pin 551 is slightly increased. Furthermore, in the anticorrosion treatment, it is difficult to control the maximum film thickness because it is necessary to secure the minimum film thickness in terms of function. In addition, when the coating liquid pool partially remains, the outer diameter of the engagement pin 551 is partially different. Even in such a case, in the present embodiment, the contact position between the engagement pin 551 and the pair of inclined surfaces 211A changes according to the outer diameter of the engagement pin 551, so that The handrail main body 51 can be fixed to the pair of frame connection portions 210 while stably holding the posture. Moreover, according to such a configuration, since it is not necessary to weld and fix the handrail connecting portion 55 and the frame connecting portion 210 after the handrail main body 51 is attached, the fixing operation time and cost of the handrail 50 are reduced compared to the conventional case. be able to.

  Hereinabove, the handrail 50 of the crane according to the embodiment of the present invention has been described. The present invention is not limited to these embodiments. In the present invention, the following modified embodiments are possible.

  (1) In the above embodiment, the engaging pin 551 is described as having a cylindrical shape, but the present invention is not limited to this. The engaging pin 551 may have a convex semicircular shape (semi-cylindrical shape) along the approach direction (downward direction) to the engaging recess 211 in a cross section orthogonal to the front-rear direction as shown in FIG. . In this case, the outer peripheral surface of the engagement pin 551 can be stably in contact with the pair of inclined surfaces 211A, and the member cost of the engagement pin 551 can be reduced as compared with the above embodiment. On the other hand, in the above embodiment, the rigidity of the handrail connecting portion 55 is held high by the engagement pin 551 having a cylindrical shape. The shape of the engagement pin 551 is not limited to the above, and may be another shape such as a rectangular shape in cross section.

  (2) Moreover, FIG. 10 is sectional drawing of the handrail connection part 550, the flame | frame connection part 210, and the connection pin 60 of the handrail which concerns on the modified embodiment of this invention. In the present modified embodiment, members having the same functions as those of the previous embodiment are denoted by the same reference numerals as those in FIGS. In the previous embodiment, the pair of handrail connection parts 55 constitute one pair of connection parts of the present invention, and the pair of frame connection parts 210 constitute the other pair of connection parts of the present invention. . In this modification, a pair of handrail connection parts 55 constitute the other pair of connection parts of the present invention, and a pair of frame connection parts 210 constitute one pair of connection parts of the present invention.

  With reference to FIG. 10, in the present modified embodiment, the handrail connection portion 55 has a handrail side plate-like portion 550, and the frame connection portion 210 has a pair of front and rear frame side plate-like portions 210A and an engagement pin 213. . Further, a circular hole (not shown) into which the connection pin 60 can be inserted is opened at a position spaced above the engagement pin 213 in the pair of frame side plate-like portions 210A.

  On the other hand, in the handrail side plate-like portion 550, an engagement concave portion 553 and a second hole 554 are formed. The engagement recess 553 is formed in the lower end portion 550A of the handrail side plate-like portion 550. The engagement recess 553 is defined by a pair of inclined portions 553A and a recess upper end 553B. In addition, the second hole 554 has an elongated hole shape and is disposed at a position spaced above the engagement recess 553.

  Also in the present modified embodiment, when the operator fixes the handrail 50 to the swing frame 21, the pair of handrail connection portions 55 are attached to the pair of frame connection portions 210 from above (FIG. 2). Under the present circumstances, in each handrail connection part 55, the engagement recessed part 553 formed in the handrail side plate-like-part 550 is engage | inserted from the upper direction to the engagement pin 213 arrange | positioned between a pair of flame | frame connection parts 210. As a result, as shown in FIG. 10, the outer peripheral surface of the cylindrical engaging pin 213 abuts on the pair of inclined surfaces 551A at the abutting position P3. At this time, as shown in FIG. 10, a predetermined gap is formed between the upper end portion of the engagement pin 213 and the recess upper end portion 553B. When the engagement pin 213 abuts on the pair of inclined surfaces 553A, the handrail main body 51 is restrained in the lower direction and the left and right direction. The second hole 554 is disposed between the pair of first holes (not shown). For this reason, the worker inserts the connection pin 60 in the order of the rear first hole, the second hole 554, and the front first hole, whereby the handrail side plate-like portion 550 and the frame connection portion 210 It is fixed to each other. As a result, the handrail side plate-like portion 550 is restrained also in the vertical direction with respect to the frame side plate-like portion 210A. As described above, also in this modified embodiment, the same effect as that of the previous embodiment can be obtained. Further, as in the present modified embodiment, when the engagement pin 213 is disposed on the frame connection portion 210 side, since there is a space corresponding to the turning frame 21, the pair of engagement pins 213 is secured while securing the length thereof. The plate thickness of the frame side plate-like portion 210A can be easily increased.

  Note that, in the previous embodiment (FIG. 6), the engaging pin 551 is fitted into the engaging recess 211 from above as compared with the present modified embodiment. Therefore, the worker can easily attach the handrail main body 51 to the pair of frame connecting portions 210. In particular, when assembling the handrail main body 51 to the turning frame 21, the space (concave portion) between the pair of inclined surfaces 211 </ b> A disposed in the frame connecting portion 210 opens upward. For this reason, it is easy for the worker to confirm that the engagement pin 551 of the handrail connection portion 55 is inserted from above into the space portion. For this reason, the worker can attach the handrail main body 51 easily and reliably.

1 lower traveling body 2 upper swing body 21 swing frame (airframe)
210 Frame connection part (airframe connection part)
210A Frame side plate-like part (second member)
211 Engaging recess (recess)
211A, 553A inclined surface 211B concave lower end 212, 554 second hole 21S frame frame side 21H frame upper surface 50 handrail 51 handrail main body 511 gripped portion 512 vertical frame 52 horizontal frame 53 connection frame 54 rib 55 handrail connection 550 handrail Side plate portion (first member)
551 Engagement pin (connection part)
552 1st hole 60 connection pin

Claims (6)

Handrails provided to the fuselage of work machines,
A handrail main body having a gripped portion gripped by an operator, and a pair of handrail connection portions arranged at intervals in a first horizontal direction below the gripped portion;
A pair of airframe connecting portions fixed to the airframe so as to be spaced apart in the first direction, and allowing the pair of handrail connecting portions to be connected respectively;
A pair of connecting pins that respectively connect the pair of handrail connecting portions and the pair of airframe connecting portions;
Equipped with
One of the pair of handrail connection portions and the one pair of connection portion of the pair of airframe connection portions are:
A pair of first members which are respectively disposed orthogonal to the first direction and which face each other in the first direction,
A connecting portion having an outer peripheral surface extending in the first direction between the pair of first members, and connecting the pair of first members to each other;
, And the pair of first members of the one pair of connecting portions are arranged to be opposed to each other in the first direction at positions spaced apart from each other in the vertical direction with respect to the connecting portion A pair of first holes into which pins can be inserted are respectively formed,
The other pair of connecting portions of the pair of handrail connecting portions and the pair of body connecting portions have an upper end portion and a lower end portion, and are disposed orthogonal to the first direction, and the handrail connecting portion and the body Each has a second member disposed between the pair of first members in connection with the connection portion,
The second members are disposed to face each other in a second direction orthogonal to the first direction and the vertical direction, respectively, and in the connection between the handrail connecting portion and the machine body connecting portion, the connecting portion extends in the vertical direction. It has a pair of restraining surfaces arranged so as to sandwich the receiving space from both sides in the second direction, and the pair of restraining surfaces have a narrow interval along the direction in which the connection part enters the space. And the connecting portion is restrained in the downward direction and the second direction by abutting on the outer peripheral surface of the connecting portion by the weight of the handrail body.
Furthermore, the connection pin is inserted at a position vertically spaced from the pair of constraining surfaces of the second member and at positions facing the pair of first holes in the first direction. Possible second holes are formed,
In a working machine, the opening widths in the vertical direction of the pair of first holes and the second holes are set such that the second holes include the pair of first holes in the vertical direction. handrail. When viewed in a cross section orthogonal to the first direction,
The outer peripheral surface of the connection portion includes a pair of contact portions each formed of a convex curve toward the pair of constraining surfaces,
The pair of constraining surfaces comprises a pair of straight lines or a pair of concave curves toward the pair of abutments,
The work according to claim 1, wherein the radius of curvature of the contact portion is set smaller than the radius of curvature of the constraining surface such that the contacting portion contacts the constraining surface along the first direction. Handrail of the machine. When viewed in a cross section orthogonal to the first direction,
The pair of constraining surfaces and the pair of contact portions are arranged so as to be line symmetrical in the second direction about a center line extending in the vertical direction,
The handrail of the working machine according to claim 2, wherein the pair of first holes and the second holes are disposed on the center line.   The handrail of the working machine according to claim 2 or 3, wherein the outer peripheral surface of the connection portion has a circular shape including the pair of contact portions when viewed in a cross section orthogonal to the first direction.   The second member has an inner circumferential surface that defines the second hole, and the inner circumferential surface abuts on the connection pin inserted into the first hole, thereby using the connection portion as a fulcrum. The handrail of the working machine according to any one of claims 2 to 4, wherein an opening width of the second hole in the second direction is set such that rotation of the handrail main body is restricted.   The work according to any one of claims 1 to 5, wherein the one pair of connecting portions is the pair of handrail connecting portions, and the other of the pair of connecting portions is the pair of airframe connecting portions. Handrail of the machine.

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