JP6419591B2 - Excavator - Google Patents

Description

  The present invention relates to an excavator provided with a handrail unit.

  An excavator as a construction machine often has an upper turning body that can turn on a lower traveling body. The upper swing body is provided with a cab (cabin) in which a driver's seat is provided. In addition to the cab, an engine as a power source and a fuel tank attached to the engine are also provided in the upper swing body. Furthermore, many parts including a hydraulic pump as a hydraulic drive source are provided in the upper swing body.

  When inspecting or repairing the parts provided on the upper swing body, the operator needs to climb on the upper swing body to perform work. In many cases, a handrail (also referred to as a handrail) to be gripped when an operator climbs the upper swing body is provided on the upper swing body.

  In general, the handrail is formed by bending an elongated pipe having a shape that can be easily grasped by an operator. By fixing both ends of the handrail to the frame or sturdy parts of the upper swing body, the handrail is installed on the upper swing body. (For example, refer to Patent Document 1).

JP 2006-31847 A

  When both ends of the handrail are fixed to the upper swing body, vibration and impact when the upper swing body swings are directly transmitted to the handrail. For this reason, a large load is applied to the fixed portions at both ends of the handrail, and the fixed portions may be damaged when used for a long time. In addition, when a large load is applied to the center of both ends of the handrail, the load concentrates on the fixed portion that supports the handrail, and the fixed portion may be deformed or damaged.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an excavator having a handrail unit that has a sturdy fixed portion and is firmly attached to an upper swing body.

In order to achieve the above object, according to an embodiment of the present invention, an excavator having a revolving body having a revolving frame on which an engine and a fuel tank are mounted, and a handrail unit attached to the revolving body. The handrail unit includes a lower seat member and an upper seat member fixed to the revolving body, a first bar member fixed to the lower seat member, and a second bar shape fixed to the upper seat member. and the member is connected between the first rod-like member and the second rod-like member, and a third rod-like member functioning as a hand rail for the worker, the first or second rod-like member Is connected to the third rod-like member by welding, and an excavator is provided in which the outer diameters of the first and second rod-like members are larger than the outer diameter of the third rod-like member.

  According to the disclosed embodiment, the handrail unit is fixed to the revolving unit with the first and second rod-shaped members that are thicker than the third bar-shaped member serving as the handrail as a fixed portion. For this reason, a fixed part is sturdy and can endure long-term use. Moreover, the fixed part of the handrail unit can be firmly attached to the revolving structure.

It is a right view of the shovel which is an example of the construction machine by one Embodiment. It is a right view of the upper revolving body provided with the handrail unit. It is a top view of the upper revolving body provided with the handrail unit. It is a front view of the upper revolving structure provided with the handrail unit. It is a figure which shows a handrail unit. It is an expanded sectional view of a connecting member. It is an expanded sectional view of the modification of a connection member. It is a side view of the modification of a handrail unit. It is a figure which shows the other modification of a handrail unit.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a right side view of an excavator as an example of a construction machine according to an embodiment.

  As shown in FIG. 1, the excavator includes a lower traveling body 1, an upper swing body 2, a cab 3, a boom 4, an arm 5, and a bucket 6. The upper swing body 2 is mounted on the lower traveling body 1 via a swing mechanism (not shown). A cab 3 having a driver's seat inside is disposed at the front left side of the upper swing body 2. One end of the boom 4 is rotatably attached to the front center of the upper swing body 2. The arm 5 is pivotally attached to the tip of the boom 4. The bucket 6 that is an end attachment is rotatably attached to the tip of the arm 5. Instead of the bucket 6 that is a drilling attachment, an end attachment such as a breaker or a crusher may be attached to the tip of the arm 5.

  When performing a part or the like mounted on the upper swing body 2 of the shovel shown in FIG. 1, the operator needs to climb on the upper swing body 2. Therefore, a handrail for holding and supporting the body when the worker climbs the upper swing body 2 is attached to the upper swing body 2.

  The configuration of the shovel to which the handrail unit is attached will be described with reference to FIGS. 2 to 4 in addition to FIG. FIG. 2 is a right side view of the upper-part turning body provided with the handrail unit. FIG. 3 is a plan view of the upper swing body provided with the handrail unit. FIG. 4 is a front view of the upper-part turning body provided with the handrail unit. 2 to 4 show a state in which the boom 4 is removed for convenience of illustration. In the present specification, the direction in which the boom 4 is attached as viewed from the center of the upper swing body 2 is defined as the front and defined as the rear on the opposite side. Further, when looking forward at the center of the upper swing body 2, the left hand side is defined as the left side, and the right hand side is defined as the right side.

  An engine room 7 is formed behind the upper swing body 2, and an engine (not shown) is disposed in the engine room 7. The engine room 7 is covered with an engine hood 30. The engine hood 30 is rotatably supported by a hinge 30a. Therefore, the engine hood 30 can be opened in the direction indicated by the arrow A in FIG. 2 by grasping and lifting the handle 30b attached to the opposite side of the hinge 30a. That is, the engine hood 30 can be opened when inspecting and maintaining the components such as the engine and the exhaust gas treatment device installed in the engine room 7.

  A fuel tank 19 that stores fuel supplied to the engine is disposed on the right side in front of the engine room 7. Guard rails 32, 34 and catwalk stays 32 a, 34 a are provided above the side surface side of the fuel tank 19.

  A guard rail 36 and catwalk stays 32a and 34a are provided on the left side in front of the engine room 7 (opposite the fuel tank 19).

  An upper surface cover 38 is provided in the center of the front of the engine room 7. As described above, when the operator opens the engine hood 30 for inspection and maintenance, the operator can get on the top cover 38 and perform work.

  The guard rails 34 and 36 have portions 34b and 36b extending inward, respectively. That is, the portion 34b of the guard rail 34 extends toward the center and overlaps the right portion of the engine hood 30 when viewed from the front side. Further, the portion 36b of the guard rail 36 extends toward the center, and overlaps the left portion of the engine hood 30 when viewed from the front side.

  No guardrail is provided in the central region (the region indicated by the one-dot chain in FIG. 4) between the portions 34b and 36b of the guardrails 34 and 36. As a result, the operator can open the engine hood 30 without being obstructed by the guardrail, and can perform inspection / maintenance in the engine room 7.

  A processing agent tank (not shown) for storing a processing agent (for example, urea water) for processing the exhaust gas of the engine is disposed in front of the fuel tank 19. The treatment agent tank is covered with a treatment agent tank cover 40. The upper surface of the processing agent tank cover 40 is partially lowered, and a step is provided. This level | step difference forms the staircase used when an operator climbs to the upper turning body 2. FIG.

  A tool box 22 that can store a work tool and a work machine is disposed in front of the treatment agent tank cover 40. The upper surface of the tool box 22 is also used as a part of the stairs used when the worker climbs on the upper swing body 2. When the processing agent tank and the processing agent tank cover 40 are not disposed in front of the fuel tank 19, a step is provided on the upper surface of the fuel tank 19, and the tool box 22 may be disposed in front of the fuel tank 19. .

  The components constituting the upper revolving unit 2 are mounted on the revolving frame 2a. In front of the part on which the tool box 22 is mounted, a step 23 is provided as a footrest used as a part of the stairs used when the worker climbs the upper swing body 2. The step 23 is attached to the inclined side surface of the revolving frame 2a in front of the portion where the tool box 22 is mounted.

  As described above, the step 23, the upper surface of the tool box 22, the upper surface of the processing agent tank cover 40, and the upper surface of the fuel tank 19 form a step used when the worker climbs the upper swing body 2. A handrail unit 50 is attached in the vicinity of the stairs formed in this way. The handrail unit 50 is disposed on the front right side of the upper swing body 2 opposite to the cab 3 disposed on the left side of the front part. A boom support bracket 17 that supports the boom 4 in a turnable manner is fixed to the front center of the upper swing body 2. Therefore, the above-mentioned staircase is formed between the boom support bracket 17 and the handrail unit 50.

  The handrail unit 50 includes a handrail 52 (third bar-shaped member) as a first handrail for an operator to hold and support the body. The handrail unit 50 includes a handrail 54 (fifth bar-like member) as a second handrail extending in the horizontal direction below the handrail 52. The handrail 54, also referred to as a catwalk stay, functions as a handrail for the worker and also functions as a reinforcing member that reinforces the handrail unit 50 (handrail 52).

  One end (low side) of the handrail unit 50 is fixed to the side surface of the revolving frame 2 a, and the other end (high side) is fixed to the upper surface of the fuel tank 19. More specifically, the lower seat member 56 is attached to one end (lower side) of the handrail unit 50 (hand rail 52), and the lower seat member 56 is firmly fixed to the side surface of the turning frame 2a by bolting. An upper seat member 58 is attached to the other end (higher side) of the handrail unit 50 (hand rail 52), and the upper seat member 58 is firmly fixed to the upper surface of the fuel tank 19 by bolting.

  A large impact or vibration acts on the handrail unit 50 when the upper swing body 2 starts to turn or stops turning. Therefore, the entire structure and the fixing structure of the handrail unit 50 so that the fixed portion is not deformed even when a large load is applied to the handrail unit 50 and the fixed portion of the handrail unit 50 is not damaged by long-term use. Has been devised.

  Here, the structure of the handrail unit 50 will be described in detail with reference to FIG. 5A and 5B are diagrams showing the handrail unit 50. FIG. 5A is a side view of the handrail unit 50, FIG. 5B is a plan view of the handrail unit 50, and FIG. 5C is a handrail unit. FIG.

  As described above, the handrail unit 50 includes the handrail 52 and the handrail 54 that function as handrails, and the lower seat member 56 and the upper seat member 58. The lower seat member 56 and the upper seat member 58 are fixing portions for fixing the handrail unit 50 to the upper swing body 2.

  The handrail 52 is preferably formed of a steel pipe material, but is not particularly limited to a pipe material as long as it is a rod-shaped member that can be grasped by an operator. That is, the handrail 52 may be formed of a solid round bar. Moreover, the material of the handrail 52 is not limited to steel as long as the material can ensure strength. Other metals may be used as the material of the handrail 52 as long as sufficient strength can be secured, bending is easy, and the metal can be welded. After the handrail unit 50 is attached to the upper swing body 2, the handrail 52 is painted as a rust preventive treatment. However, if the handrail 52 is made of a material that hardly rusts, for example, a pipe material such as stainless steel, There is no need to paint.

  A rail support member 57 (first rod-like member) is fixed to the lower seat member 56. In the present embodiment, the rail support member 57 is formed of a steel pipe material. The material of the rail support member 57 can be the same material as the handrail 52. However, the outer diameter of the rail support member 57 is larger than the outer diameter of the hand rail 52, and the rail support member 57 has greater strength than the hand rail 52. The inner diameter of the rail support member 57 is slightly larger than the outer diameter of the hand rail 52, and the hand rail 52 is joined to the rail support member 57 by welding in a state where one end of the hand rail 52 is inserted into the rail support member 57. The annular upper end surface of the rail support member 57 is welded to the outer peripheral surface of the handrail 52 over the entire circumference so that rainwater or the like does not enter the rail support member 57. Alternatively, a seal member may be filled between the outer peripheral surface of the inserted hand rail 52 and the inner peripheral surface of the rail support member 57.

  Similar to the lower seat member 56, a rail support member 59 (second bar-like member) is fixed to the upper seat member 58, and one end of the handrail 52 is inserted and fixed inside the rail support member 59. In the present embodiment, the rail support member 59 is formed of a steel pipe material. The material of the rail support member 59 can be the same material as that of the handrail 52. However, the outer diameter of the rail support member 59 is larger than the outer diameter of the handrail 52, and the rail support member 59 has greater strength than the handrail 52. The inner diameter of the rail support member 59 is slightly larger than the outer diameter of the hand rail 52, and the hand rail 52 is joined to the rail support member 59 by welding in a state where one end of the hand rail 52 is inserted into the rail support member 59. By welding the annular upper end surface of the rail support member 59 to the outer peripheral surface of the handrail 52 over the entire circumference, rainwater or the like is prevented from entering the rail support member 59. Alternatively, a seal member may be filled between the outer peripheral surface of the inserted hand rail 52 and the inner peripheral surface of the rail support member 57.

  The handrail unit 50 includes a handrail 60 (fourth rod-like member) extending substantially parallel to a rail support member 57 that stands vertically from the lower seat member 56. The handrail 60 also functions as a handrail and has a function of reinforcing the fixing of the rail support member 57 (first rod-shaped member) to the lower seat member 56. The handrail 60 is preferably formed of a steel pipe material having the same diameter as the handrail 52, but is not limited to the same pipe material. The handrail 60 extends substantially parallel to the rail support member 57 at a position separated from the rail support member 57 by a distance that can be grasped by the hand of the operator.

  One end of the handrail 54, also referred to as the above-described catwalk stay, is fixed to the rail support member 57, and the other end is fixed to the upper seat member 58. In the present embodiment, the handrail 54 is formed of a steel pipe material having the same diameter as the handrail 52, but is not limited to the same pipe material. The handrail 54 extends horizontally at a position lower than the handrail 52 and functions as a handrail, and also functions as a reinforcing member that reinforces the handrail unit 50.

  One end side of the handrail 54 is bent in the horizontal direction as shown in FIG. 5B, and the end face of the end bent in the horizontal direction is joined to the upper seat member 58 by welding. As shown in FIG. 5A, the other end side of the handrail 54 is bent vertically downward along the rail support member 57, and the bent end portion is connected to the rail support member via the connection member 70. 57. The connection member 70 will be described in detail later.

  One end (upper end) of the handrail 60 is fixed to the outer peripheral surface of the upper end portion of the rail support member 57 erected vertically from the lower seat member 56 by welding. It is preferable to connect one end of the handrail 60 to the rail support member 57 by welding, but other connection methods such as brazing and screw tightening may be used. The other end (lower end) of the handrail 60 is connected to the lower seat member 56 by welding. It is preferable to connect the other end of the handrail 60 to the lower seat member 56 by welding, but other connection methods such as brazing and screw tightening may be used.

  As shown in FIG. 3, the extending direction of the handrail 54 substantially coincides with the front-rear direction of the upper swing body 2. In the present embodiment, as shown in FIG. 5B, the handrail 60 is inclined at a predetermined angle with respect to the extending direction of the handrail 54. Further, the extending direction of the handrail 52 is also inclined at a predetermined angle with respect to the extending direction of the handrail 54.

  The lower seat member 56 is a sturdy member formed of a metal plate such as a steel plate. The lower seat member 56 includes a base plate 56a, two rib plates 56b and 56c, and an upright plate 56d extending substantially vertically upward from the base plate 56a.

  The base plate 56a is formed by bending a steel plate at a predetermined angle, and the horizontal plate 56a-1 and the inclined plate 56a-2 are formed by this bending. The inclination angle of the inclined plate 56a-2 is the same as the inclination angle of the side surface of the revolving frame 2a of the upper revolving structure 2. Thereby, as shown in FIG. 3, when the inclined plate 56a-2 of the base plate 56a is fixed to the side surface of the turning frame 2a of the upper turning body 2, the horizontal plate 56a-1 extends in the horizontal direction.

  Each of the two rib plates 56b and 56c of the lower seat member 56 is welded to both the horizontal plate 56a-1 and the inclined plate 56a-2 on the back side of the base plate 56a. Each of the two rib plates 56b and 56c functions as a rib that gives rigidity to the base plate 56a so that the bent shape of the base plate 56a is maintained.

  The lower end of the upright plate 56d of the lower seat member 56 is welded to the horizontal plate 56a-1 of the base plate 56a. And the rail support member 57 which is the above-mentioned steel pipe material is welded with respect to the standing board 56d and the horizontal board 56a-1 so that it may stand upright along the standing board 56d. That is, the lower end surface of the rail support member 57 is welded to the horizontal plate 56a-1, and the outer peripheral surface of the rail support member 57 is welded to the upright plate 56d by the length in the vertical direction of the upright plate 56d.

  As described above, the rail support member 57 is firmly fixed to the lower seat member 56. Further, since the handrail 60 is attached between the upper end portion of the rail support member 57 and the horizontal plate 56 a-1 of the lower seat member 56 as described above, the rail support member 57 is stronger than the lower seat member 56. Fixed to.

  The upper seat member 58 is a sturdy member formed of a metal plate such as a steel plate. The upper seat member 58 includes a base plate 58a and a rib plate 58b.

  The pedestal plate 58a is formed by bending a steel plate at a right angle, and includes a horizontal plate 58a-1 extending horizontally and a rib plate 58a-2 extending vertically upward from the horizontal plate 58a-1. A rib plate 58b formed of a steel plate is welded to the edges of the horizontal plate 58a-1 and the rib plate 58a-2. Accordingly, the rib plate 58a-2 and the rib plate 58b are erected vertically upward from two orthogonal sides of the substantially quadrangular horizontal plate 58a-1, and the rib plate 58a-2 and the rib plate 58b are orthogonally welded to each other. Is done.

  As described above, the upper seat member 58 has a structure in which the rib plate 58a-2 and the rib plate 58b that are orthogonal to each other with respect to the horizontal plate 58a-1 are welded. Thereby, the upper seat member 58 has great rigidity.

  A rail support member 59 made of the above-described steel pipe material is disposed at a right-angled corner formed by the rib plate 58a-2 and the rib plate 58b of the upper seat member 58. The end surface of the rail support member 59 is welded to the horizontal plate 58a-1 of the upper seat member 58. The outer peripheral surface of the rail support member 59 is welded to both the rib plate 58a-2 and the rib plate 58b by the length in the vertical direction. As a result, the rail support member 59 is firmly fixed to the upper seat member 58.

  In the handrail unit 50 described above, the rail support members 57 and 59 may be formed of a hollow pipe material so that the end of the handrail 52 can be inserted and fixed to the rail support members 57 and 59. preferable. The outer diameter of the handrail 52 is preferably 15 mm or more in consideration of ease of gripping by hand and strength. Therefore, the inner diameters of the rail support members 57 and 59 are preferably slightly larger than 15 mm so that a pipe material of 15 mm can be inserted. Considering the thickness of the rail support members 57 and 59, the outer diameter of the rail support members 57 and 59 is preferably 19 mm or more.

  on the other hand. When the outer diameter of the rail support members 57 and 59 exceeds 50 mm, the handrail unit 50 becomes too heavy, and the outer diameter of the handrail 52 that can be inserted becomes large. Therefore, the outer diameter of the rail support members 57 and 59 is preferably 50 mm or less. As described above, it is preferable that the outer diameters of the rail support members 57 and 59 (first and second rod-like members) are 19 mm or more and 50 mm or less. In this embodiment, it is preferable that the rail support members 57 and 59 are made of a pipe material having an outer diameter of 48.6 mm.

  When the outer diameters of the rail support members 57 and 59 are 50 mm, the outer diameter of the handrail 52 is preferably 38 mm or less in consideration of the thickness of the rail support members 57 and 59. As described above, since the outer diameter of the handrail 52 is preferably 15 mm or more, the outer diameter of the handrail 52 is preferably 15 mm or more and 38 mm or less.

  When the outer diameter of the handrail 52 is a minimum of 15 mm and the outer diameter of the rail support members 57 and 59 is a minimum of 19 mm, the difference between the outer diameter of the handrail 52 and the outer diameter of the rail support members 57 and 59 is 4 mm. Become.

  On the other hand, when the outer diameter of the handrail 52 is set to the minimum of 15 mm and the outer diameter of the rail support members 57 and 59 is set to the maximum of 50 mm, the difference between the outer diameter of the handrail 52 and the outer diameter of the rail support members 57 and 59 is 35 mm. However, if this outer diameter difference is 35 mm, the thickness of the rail support members 57 and 59 is 17.5 mm, and the weight is too large. Therefore, in order to make the thickness 10 mm or less, the difference between the outer diameter of the handrail 52 and the outer diameters of the rail support members 57 and 59 is preferably 20 mm or less. Considering the above, the difference between the outer diameter of the handrail 52 and the outer diameters of the rail support members 57 and 59 is preferably 4 mm or more and 20 mm or less.

  In this embodiment, the rail support members 57 and 59 are made of a pipe material having an outer diameter of 48.6 mm and a thickness of about 7 mm, and the handrail 52 is made of a pipe material having an outer diameter of 34 mm. In the present embodiment, the handrails 54 and 60 are formed using the same pipe material as the handrail 52.

  The handrail unit 50 configured as described above is attached to the front right side of the upper swing body 2. Specifically, the inclined plate 56 a-2 of the lower seat member 56 is bolted and fixed to the inclined side surface of the revolving frame 2 a, and the horizontal plate 58 a-1 of the upper seat member 58 is bolted to the upper surface of the fuel tank 19. It is fixed with. As shown in FIG. 3, the inclined plate 56a-2 of the lower seat member 56 is fixed to the outside of the step 23 attached to the inclined side surface of the revolving frame 2a. As shown in FIG. 3, the horizontal plate 58 a-1 of the upper seat member 58 is fixed to the front right side on the upper surface of the fuel tank 19.

  Thereby, the handrail unit 50 is firmly attached to the vicinity of the steps formed by the step 23, the upper surface of the tool box 22, the upper surface of the processing agent tank cover 40, and the upper surface of the fuel tank 19.

  Next, the connection member 70 (see FIG. 5A) that connects the handrail 54 and the rail support member 57 will be described.

  As shown in FIG. 5A, the end portion of the handrail 54 that is bent vertically downward along the rail support member 57 is connected to the rail support member 57 via the connection member 70. FIG. 6 is a view showing a cross section of the connecting member 70, and is an enlarged cross sectional view taken along line VI-VI in FIG.

  The connection member 70 includes a first joint portion 72 having a shape along the outer peripheral surface of the handrail 54 and a second joint portion 74 having a shape along the outer peripheral surface of the rail support member 57. The first joint 72 and the second joint 74 are connected by an intermediate portion 76.

  The first joint portion 72 is formed by bending a steel plate in a semicircular shape. The curvature of the semicircular inner surface of the first joint 72 is substantially equal to the curvature of the outer peripheral surface of the handrail 54. Therefore, the inner surface of the first joint portion 72 is in contact with the outer peripheral surface of the handrail 54 over a half circumference. In a state where the first joint 72 is in contact with the outer peripheral surface of the handrail 54 over a half circumference, both side surfaces of the first joint 72 are welded to the outer peripheral surface of the handrail 54. In FIG. 6, a portion that is built up by welding is indicated by W.

  The second joining portion 74 is formed by bending a steel plate in a semicircular shape. The curvature of the semicircular inner surface of the second joint portion 74 is substantially equal to the curvature of the outer peripheral surface of the rail support member 57. Therefore, the inner surface of the second joint 74 abuts the outer peripheral surface of the rail support member 57 over a half circumference. In a state where the second joint 74 is in contact with the outer peripheral surface of the rail support member 57 over a half circumference, both side surfaces of the second joint 74 are welded to the outer peripheral surface of the rail support member 57. In FIG. 6, a portion that is built up by welding is indicated by W.

  Between the outer peripheral surface of the 1st junction part 72 and the 2nd junction part 74 outer peripheral surface, the intermediate part 76 formed with the steel plate in the center part of a semicircle is arrange | positioned. The outer peripheral surface of the first joint portion 72 is welded to one side of the intermediate portion 76, and the outer peripheral surface of the second joint portion 74 is welded to the side opposite to the intermediate portion 76. In FIG. 6, a portion that is built up by welding is indicated by W.

  By connecting the end portion of the handrail 54 to the rail support member 57 with the connection member 70 having the above configuration, the load and impact transmitted between the rail support member 57 and the handrail 54 can be distributed over a wide portion. It is possible to suppress stress concentration on the joint due to welding.

  That is, since the first joint portion 72 is in contact with the handrail 54 over a half circumference, the load transmitted from the rail support member 57 via the intermediate portion 76 can be received by the half circumference of the handrail 54. Therefore, stress concentration at the welded portion is suppressed. Similarly, since the second joining portion 74 is in contact with the rail support member 57 over a half circumference, the load transmitted from the hand rail 54 via the intermediate portion 76 can be received in the almost half circumference of the rail support member 57. Therefore, stress concentration at the welded portion is suppressed.

  7 is a view showing a cross section of a connection member 80 which is a modification of the connection member 70, and corresponds to an enlarged cross-sectional view of FIG. The connecting member 80 shown in FIG. 7 is created by bending a single steel plate. The connection member 80 includes a first joint portion 82 having a shape along the outer peripheral surface of the handrail 54 and a second joint portion 84 having a shape along the outer peripheral surface of the rail support member 57. An intermediate portion 86 is formed between the first joint portion 72 and the second joint portion 74.

  The first joint portion 82 is formed by bending a part of a steel plate in a semicircular shape. The curvature of the semicircular inner surface of the first joint 72 is substantially equal to the curvature of the outer peripheral surface of the handrail 54. Therefore, the inner surface of the first joint portion 72 is in contact with the outer peripheral surface of the handrail 54 over a half circumference. In a state where the first joint 82 is in contact with the outer peripheral surface of the handrail 54 over a half circumference, both side surfaces of the first joint 82 are welded to the outer peripheral surface of the handrail 54. In FIG. 7, a portion that is built up by welding is indicated by W.

  The second joint portion 84 is formed by bending a part of the steel plate on which the first joint portion 82 is formed into a semicircular shape. The curvature of the semicircular inner surface of the second joint portion 84 is substantially equal to the curvature of the outer peripheral surface of the rail support member 57. Therefore, the inner surface of the second joint portion 84 abuts the outer peripheral surface of the rail support member 57 over a half circumference. In a state where the second joint 84 is in contact with the outer peripheral surface of the rail support member 57 over a half circumference, both side surfaces of the second joint 84 are welded to the outer peripheral surface of the rail support member 57. In FIG. 7, a portion that is built up by welding is indicated by W.

  By connecting the end portion of the handrail 54 to the rail support member 57 with the connecting member 80 having the above configuration, the load and impact transmitted between the rail support member 57 and the handrail 54 can be distributed over a wide portion. It is possible to suppress stress concentration on the joint due to welding.

  The connection members 70 and 80 described above can also be used for a connection portion between the handrail 60 and the rail support member 57. FIG. 8 is a side view of the handrail unit 50 when the connection member 70 is used at the connection portion between the handrail 60 and the rail support member 57.

  In the handrail unit 50 described above, one end of the handrail 54 is bent downward, and the bent portion is connected to the rail support member 57 via the connecting member 70. As shown in FIG. One end may be directly welded to the handrail 52.

  Further, in the handrail unit 50A shown in FIG. 9, the upright plate 56d is not provided on the lower seat member 56A. Therefore, the rail support member 57 is only welded to the horizontal plate 56 a-1 and is reinforced by the handrail 60. The handrail unit 50A is designed to fit a relatively small excavator, and the impact and load applied to the handrail unit 50A are relatively small. Therefore, even such a structure can withstand long-term use.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving body 2a Turning frame 3 Cab 4 Boom 5 Arm 6 Bucket 7 Engine room 19 Fuel tank 22 Tool box 23 Step 40 Treatment agent tank cover 50, 50A Handrail unit 52, 54, 60 Hand rail 56 Below Seat member 57, 59 Rail support member 58 Upper seat member 70, 80 Connection member

Claims (8)

A revolving structure having a revolving frame on which an engine and a fuel tank are mounted;
An excavator having a handrail unit attached to the revolving structure,
The handrail unit is
A lower seat member and an upper seat member fixed to the revolving structure,
A first rod-like member fixed to the lower seat member;
A second bar-shaped member fixed to the upper member;
A third rod-shaped member connected between the first rod-shaped member and the second rod-shaped member and functioning as a handrail for an operator;
The first or second bar member is connected to the third bar member by welding,
An excavator in which the outer diameters of the first and second rod-shaped members are larger than the outer diameter of the third rod-shaped member. The excavator according to claim 1,
The upper seat member is a shovel having ribs extending in the front-rear direction of the revolving structure. The excavator according to claim 1 or 2,
The upper seat member is a shovel having ribs extending in the left-right direction of the revolving structure. The excavator according to any one of claims 1 to 3,
The first, second and third rod-shaped members are hollow pipe materials,
The outer diameter of the third rod-shaped member is an excavator that is smaller than the inner diameter of the first and second rod-shaped members. The excavator according to any one of claims 1 to 4,
The handrail unit further includes a fourth bar-shaped member extending substantially parallel to the first bar-shaped member,
The outer diameter of the fourth rod-shaped member is smaller than the outer diameter of the first rod-shaped member,
A shovel in which a lower end portion of the fourth rod-shaped member is fixed to the lower seat member, and an upper end portion of the fourth rod-shaped member is connected to the first rod-shaped member. An excavator according to any one of claims 1 to 5,
The difference between the outer diameter of the first and second rod-shaped members and the outer diameter of the third rod-shaped member is 4 mm or more and 20 mm or less. The excavator according to any one of claims 1 to 6,
A footrest member fixed to a side surface of the swivel frame;
The lower seat member of the handrail unit is an excavator disposed outside the footrest member. The excavator according to any one of claims 1 to 7,
The handrail unit further includes a fifth rod-shaped member having an outer diameter smaller than that of the first and second rod-shaped members,
One end of the fifth rod-shaped member is fixed to the upper seat member, and the other end of the fifth rod-shaped member is fixed to the third rod-shaped member.

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