CATWALK FOR CONSTRUCTION MACHINE

Abstract

A catwalk for a machine is disclosed. The machine may have an upper slewing body. The catwalk may be a passage extending from a front end to a rear end. The catwalk may be installed along a side surface of the upper slewing body. The catwalk may have a fixed portion. The fixed portion may extend from adjacent the front end to adjacent a central location disposed between the front end and the rear end. The catwalk may also have a movable portion. The movable portion may extend from adjacent the central location to adjacent the rear end. The movable portion may be pivotable about an axis positioned generally parallel to the upper slewing body.

Description

TECHNICAL FIELD

The present invention relates to a catwalk that is a passage for inspection work provided on a construction machine with an upper slewing body.

BACKGROUND ART

A large-sized construction machine with an upper slewing body, for example, a hydraulic excavator, has a large vehicle height, and it is therefore difficult for an operator on the ground to perform inspection work and the like on apparatuses arranged on the upper slewing body. Accordingly, a catwalk that is a passage for inspection work is provided on a side surface of the upper slewing body (see, for example, Patent Document 1).

The catwalk is fixed to the side surface of the upper slewing body. Thus, when the upper slewing body is slewed, the operator can consciously avoid collision against an obstacle located above and laterally to the catwalk. However, disadvantageously, a longitudinal end of the catwalk located behind the operator and corresponding to the outermost side of the slewing may come into contact with and be damaged by an obstacle such as a mountain of excavated and accumulated sediment located laterally to the catwalk. Moreover, this deformation prevents a service door on a side surface of the upper slewing body from being opened. This in turn precludes inspection work on apparatuses inside the door.

A technique for solving this problem has been developed. For example, the whole catwalk is attached to the upper slewing body so as to be able to pivot upward from a horizontal orientation so that, upon coming into contact with an obstacle, the whole catwalk is pivoted upward (see, for example, Patent Document 2).

In another example, a portion of a catwalk located in a rear portion of the vehicle can be stored under a portion of the catwalk fixedly installed in a front portion of the vehicle so that, during a slewing operation, the rear portion of the catwalk is stored to prevent contact with an object, whereas, during inspection work, the rear portion of the catwalk is brought back to a non-stored position (see, for example, Patent Document 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 2006-45853

Patent Document 2: Japanese Patent Application Laid-Open No. 2000-303500

Patent Document 3: Japanese Patent Application Laid-Open No. H5-179676

These improved catwalks still have problems to be solved as described below.

In the structure in which the whole catwalk is mounted so as to be pivotable upward from the horizontal orientation, a mounting bracket (a component 6 in FIG. 2 of Patent Document 2) is gouged over a large area in order to avoid the trajectory of pivoting movement of a tread plate (a component 3b in FIG. 2 of Patent Document 2) located inside the center of the pivoting movement. Thus, when the operator steps on the tread plate located inside the center of the pivoting movement, the catwalk pivots and becomes unstable. Furthermore, due to the gouging, providing the bracket with rigidity is difficult, and the bracket is easily damaged and deformed. Furthermore, as the difference in height between an outer end (a component 3a in FIG. 2 of Patent Document 2) that comes into contact with an obstacle and the center of pivoting movement increases, reaction force from the obstacle is more likely to act as a force that causes the catwalk to pivot. The range of the gouging and the likelihood of the bracket being damaged and deformed increase consistently with the difference in height. Moreover, in a configuration where the catwalk is fixedly held at an upper pivoting movement position, the whole catwalk needs to be returned to the original position for use. This is cumbersome.

In the configuration where a portion of the catwalk is stored in the fixed portion of the catwalk, when the operator has forgotten the storage, the portion of the catwalk may come into contact with and be damaged by an obstacle. Furthermore, the structure is complicated and involves high manufacturing costs. Moreover, when the stored portion is damaged by sediment or the like, storing or withdrawing the rear portion is difficult.

With these problems in view, it is a technical object of the present invention to provide a catwalk for a construction machine which enables effective prevention of damage resulting from contact between the catwalk during slewing and an obstacle, which allows a stable work passage to be prepared, and which has a simple structure to enable a reduction in manufacturing costs and easy handling.

DISCLOSURE OF THE INVENTION

According to the present invention, as a catwalk for a construction machine which accomplishes the above-described technical object, a catwalk for a construction machine with an upper slewing body, the catwalk being a passage extending and installed along a side surface of the upper slewing body, includes a movable portion provided at an end portion of the catwalk corresponding to a radially outermost side with respect to a slewing center of the upper slewing body, the movable portion being mounted so as to be pivotable between horizontal and vertical directions about an axis positioned on the side surface side of the upper slewing body.

Preferably, a passage surface of the movable portion is formed outside and away from the side surface of the upper slewing body, and a fixed passage surface is provided on an inside of the side surface.

Furthermore, the axis is positioned below a passage surface of the movable portion, and a bumper serving as a buffer member is mounted so as to face obliquely downward at an outer end portion, of the passage surface, away from the side surface of the upper slewing body.

Moreover, the movable portion is mounted on the axis via an elastic bearing.

According to the present invention, the catwalk that is a passage extending and installed along the side surface of the upper slewing body of the construction machine includes the movable portion at the end portion of the catwalk corresponding to the radially outermost side with respect to the slewing center of the upper slewing body, the movable portion being mounted so as to be pivotable between the horizontal and vertical directions about the axis positioned on the side surface side of the upper slewing body.

Thus, the movable portion is provided at the end portion of the catwalk corresponding to the radially outermost side with respect to the slewing center and is mounted so as to be pivotable between the horizontal and vertical directions, the end portion being likely to come into contact with an obstacle during slewing. Consequently, when the end portion comes into contact with the obstacle, the movable portion is flipped up, allowing effective prevention of damage to the catwalk. Furthermore, the movable portion is provided only at the end portion, eliminating the need to gouge a support frame and allowing a stable work passage to be prepared. Additionally, a rigid and simple structure can be inexpensively provided, and the structure is easy to handle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a side view of a hydraulic excavator that is a typical example of a construction machine with a catwalk for a construction machine configured according o the present invention,

FIG. 1(b) is a plan view of the hydraulic excavator as seen in the direction of arrow A in FIG. 1(a), and FIG. 1(c) is a rear view of a catwalk portion as seen in the direction of arrow B in FIG. 1(a).

FIG. 2 is an enlarged detailed view of a movable portion shown by C in FIG. 1.

FIG. 3 is an enlarged view of the movable portion as rotated through 90° with respect to FIG. 2 in the direction of arrow D in FIG. 2.

FIG. 4 is an enlarged cross-sectional view of a bearing portion of the movable portion taken along arrow E-E in FIG. 3.

BEST MODE FOR CARRYING OUT THE INVENTION

A catwalk for a construction machine configured according to the present invention will be described in further detail with reference to the attached drawings showing a preferred embodiment in a hydraulic excavator that is a typical construction machine with an upper slewing body.

Description will be given with reference to FIG. 1. A hydraulic excavator generally shown by reference numeral 2 includes a lower traveling body 4 and an upper slewing body 6 mounted on the lower traveling body 4 so as to be able to slew about an axis X that is a slewing center extending in the vertical direction. The upper slewing body 6 includes an operator cab 8 provided at a front end (a right end in FIG. 1(a)) of the upper slewing body 6, an engine room 10 provided behind the operator cab 8 and in which apparatuses such as an engine are housed, and a counterweight 12 provided at a rear end of the upper slewing body 6. An articulated working arm apparatus 14 with a bucket 14a is mounted on the front end side of the upper slewing body 6.

An operator operates an operating apparatus in the operator cab 8 to control traveling of the lower traveling body 4, slewing of the upper slewing body 6 (a rightward direction shown by arrow R and a leftward direction shown by arrow L), and actuation of the working arm apparatus 14 to perform operations.

The upper slewing body 6 includes a plurality of openable and closable doors DR provided on a right side surface 6a and a left side surface 6b of the upper slewing body 6 to allow maintenance and inspection to be performed on the apparatuses in the engine room 10 and the like. Catwalks 16 and 17 are installed on the respective side surfaces 6a and 6b of the upper slewing body 6 so as to extend in a front-rear direction along the side surfaces 6a and 6b; the catwalks 16 and 17 are passages utilized when the operator, for example, opens the door DR, to perform maintenance and inspection work on the apparatuses.

The catwalks 16 and 17 are laterally symmetric and basically have the same structure. Thus, the catwalks according to the present invention will be described with reference to the right catwalk 16.

A movable portion 18 is provided at an end portion of the catwalk 16 located behind the operator cab 8 and corresponding to the radially outermost side (arrow H) with respect to a slewing center X of the upper slewing body 6, the movable portion 18 being mounted so as to be pivotable between the horizontal and vertical directions about an axis Y positioned on the side surface 6a side (the upward position is shown by an alternate long and two short dashes line in FIG. 1(c)).

A well-known steel plate with an antiskid member such as a plurality of star-shaped projections formed thereon is attached to a passage surface including the movable portion 18 of the catwalk 16.

Description will be given with reference to FIG. 2 and FIG. 3 along with FIG. 1. A passage surface F1 of the movable portion 18 is formed outside and away from the axis Y positioned on the side surface 6a side of the upper slewing body 6. On the inside of the side surface 6a, a fixed passage surface F2 is formed as in the case of the remaining part of the catwalk 16.

The movable portion 18 includes two arms 20 spaced from each other in a longitudinal direction (a lateral direction in FIG. 2) of the catwalk 16. One end of the arm 20 is attached, around the axis Y, to a support frame 24 mounted on the side surface 6a of the upper slewing body 6 via a plurality of bolts 22. The tread surface F1 is formed on the other end side of the arm 20.

The axis Y, which is the center of movement of the movable portion 18, is positioned below the passage surface F1. The arm 20 is shaped like a “chevron” and extends outward and upward from the axis Y and horizontally along the passage surface F1. The horizontal position (shown by a solid line in FIG. 3) of the passage surface F1 of the movable portion 18 is defined by the arm 20 in abutting contact with a stopper 25 provided on a support frame 24. This abutting contact state may be held by an elastic rubber latch (not shown in the drawings) that is manually disengageable.

A bumper 26 is attached to an outer end portion away from the side surface 6a of the passage surface F1; the bumper 26 is a buffer member directed obliquely downward and extending fully in a longitudinal direction of the movable portion 18 (the lateral direction in FIG. 2; the direction orthogonal to the sheet of FIG. 3) . The bumper 26 is formed of synthetic rubber and has a cross section shaped like a thick cylinder with a U-shaped opening closed by a straight line. The straight line portion closing the U shape is attached to an obliquely downward facing surface of the outer end portion using a plurality of bolts 28 (in the embodiment, six bolts) inserted through holes formed in a circular arc portion of the U shape.

Thus, the movable portion 18 is mounted so as to be pivotable between the horizontal direction (shown by a solid line in FIG. 3) and the vertical direction (shown by an alternate long and two short dashes line) about the axis Y. Only a part of the movable portion 18 located outward of the axis Y is pivoted and flipped up.

A case is explained where the movable portion 18 of the catwalk 16 comes into contact with an obstacle. When the upper slewing body 6 is slewed leftward as shown by arrow L in FIG. 1(b) to bring the bumper 26 of the movable portion 18 into abutting contact with an obstacle S, a reaction force from the obstacle S shown by arrow Z1 in FIG. 3 acts on the bumper 26 of the movable portion 18. Thus, the downward facing bumper 26 located above the axis of pivot Y pushes up the movable portion 18, which is pivoted upward as shown by arrow Z2 about the axis Y. The above-described rubber latch may be installed so as to extend in accordance with the magnitude of the reaction force Z1 from the obstacle. Alternatively, the rubber latch may be adapted to be disengaged or broken in this case.

A hinge plate 30 with a hinge 30a attached to the side surface 6a side of the upper slewing body 6 is provided at a part of the passage surface F2 through which the arm 20 of the movable portion 18 passes when the movable portion 18 pivots between the “horizontal direction” and the “upward position”. The hinge plate 30 is moved up and down around the hinge 30a in conjunction with the pivoting movement of the arm 20.

The arm 20 of the movable portion 18 is mounted on the axis Y via an elastic bearing. Description will be given with reference to FIG. 4 along with FIG. 3. A boss 20a corresponding to a part of the support frame 24 of the arm 20 of the movable portion 18 which part is mounted on the axis Y is positioned between two prongs of the support frame 24. The boss 20a includes a cylindrical elastic bearing 32a inserted between a pair of spacers 32b. The arm 20 is attached to the support frame 24 using a bolt 34a passed through the support frame 24 and the elastic bearing 32a and forming the axis Y, and two nuts 34b located at the other end of the bolt 34a.

The effects of the catwalk for the construction machine as described above will be described below.

As clearly shown in FIG. 1, the catwalk 16 that is a passage extending and installed along the side surface 6a of the upper slewing body 6 of the construction machine 2 includes the movable portion 18 at the end portion of the catwalk 16 corresponding to the radially outermost side H with respect to the slewing center X of the upper slewing body 6, the movable portion 18 being mounted so as to be pivotable between the horizontal and vertical directions about the axis Y positioned on the side surface 6a side.

Thus, the movable portion 18 mounted so as to be pivotable between the horizontal and vertical directions is provided at the end portion of the catwalk 16 corresponding to the radially outermost side H with respect to the slewing center X, the end portion being likely to come into contact with the obstacle S during slewing. Thus, when the end portion comes into contact with the obstacle S, the movable portion 18 is flipped up, allowing effective prevention of damage to the catwalk 16. Furthermore, the movable portion 18 is provided only at the end portion, allowing a stable work passage to be prepared. The structure is simple, enabling a reduction in manufacturing costs, and is also easy to handle.

Furthermore, as clearly shown in FIG. 2, the passage surface F1 of the movable portion 18 is formed outside and away from the side surface 6a of the upper slewing body 6, and the fixed passage surface F2 is provided on the inside of the side surface 6a.

Therefore, a stable passage surface can be prepared by the passage surface F1 of the movable portion 18, only the outside of which is flipped up, and the inner fixed passage surface F2.

Moreover, as clearly shown in FIG. 3, the axis Y about which the movable portion 18 pivots is positioned below the passage surface F1 of the movable portion 18, and the bumper 26 serving as a buffer member is mounted so as to face obliquely downward at the outer end portion, of the passage surface F1, away from the side surface 6a.

Therefore, even when the movable portion 18 comes into contact with the obstacle S, the movable portion 18 is easily flipped up because the passage surface F1 of the movable portion 18 is offset above the axis Y and because the bumper 26 at the outer end portion of the passage surface F1 is mounted to face obliquely downward.

Furthermore, as clearly shown in FIG. 4, the movable portion 18 is mounted on the axis Y via the elastic bearing 32a.

Therefore, the elastic bearing 32a enables a reduction in impulse force applied to the movable portion 18 and also assist in upward pivoting movement of the movable portion 18.

The present invention has been described in detail based on the embodiment. However, the present invention is not limited to the above-described embodiment. For example, many variations and modifications may be made to the embodiment without departing from the scope of the present invention.

In the embodiment, the construction machine is a hydraulic excavator. However, the present invention is applicable to any other construction machine with an upper slewing body, for example, a crane truck.

In the embodiment, the movable portion is provided at the rear end portion of the catwalk behind the operator cab on the upper slewing body. However, if, for example, a front end portion corresponds to the outermost side of the slewing radius, the movable portion may be provided at the front end portion, which corresponds to the outermost side.

EXPLANATION OF REFERENCE NUMERALS

• 2 Hydraulic excavator (construction machine)
• 6 Upper slewing body
• 6 a, 6 b Side surface
• 16, 17 Catwalk
• 18 Movable portion
• 26 Bumper
• 32 a Elastic bearing
• F1, F2 Passage surface
• H Outermost side
• S Obstacle
• X Axis (slewing center)
• Y Axis

Claims

1. A catwalk for machine with an upper slewing body, the catwalk being a passage extending from a front end to a rear end and installed along a side surface of the upper slewing body, the catwalk comprising: a fixed portion extending from adjacent the front end to adjacent a central location disposed between the front end and the rear end; anda movable portion extending from adjacent the central location to adjacent the rear end, the movable portion configured to be pivotable about an axis disposed generally parallel to the upper slewing body.

2. The catwalk according to claim 1, further including: a fixed passage surface disposed adjacent the side surface.

3. The catwalk according to claim 1, wherein the axis is positioned below a passage surface of the movable portion.

4. The catwalk according to claim 1, wherein the movable portion is mounted on the axis via an elastic bearing.

5. The catwalk according to claim 2, wherein a passage surface of the movable portion is disposed spaced apart from the side surface.

6. The catwalk according to claim 1, wherein the movable portion is pivotable from a horizontal position disposed generally orthogonal to the side surface towards the side surface.

7. The catwalk according to claim 1, wherein the movable portion includes at least one arm extending away from the movable portion and configured to be attached to a frame mounted to the side surface.

8. The catwalk according to claim 7, wherein the at least one arm is generally inclined relative to the movable portion.

9. The catwalk according to claim 7, further including: a hinge attached to the side surface; anda hinge plate attached to the hinge and configured to cover the at least one arm, the hinge plate being configured to move from a horizontal position disposed generally orthogonal to the side surface towards the side surface.

10. The catwalk according to claim 1, wherein the at least one arm includes a first arm disposed adjacent the rear end and the movable portion further includes: a second arm extending away from the movable portion and configured to be attached to a frame mounted to the side surface, the second arm spaced apart from the first arm and disposed adjacent the central location.

11. The catwalk according to claim 1, wherein the movable portion includes a bumper mounted at an outer end portion of the movable portion away from the side surface of the upper slewing body.

12. The catwalk according to claim 11, wherein the bumper is mounted so as to face obliquely downward relative to a horizontal position of the movable portion.

13. The catwalk according to claim 12, wherein the bumper is mounted to the movable portion using at least one fastener.

14. A machine comprising: a lower body;an upper body mounted to the lower body, the upper body including a side surface extending from a front end to a rear end;an engine configured to propel the lower body; anda catwalk installed along the side surface, the catwalk being a passage extending from the front end to the rear end, the catwalk including: a fixed portion extending from adjacent the front end to adjacent a central location disposed between the front end and the rear end; anda movable portion extending from adjacent the central location to adjacent the rear end, the movable portion configured to be pivotable about an axis disposed generally parallel to the side surface.

15. The machine according to claim 14, further including a fixed passage surface disposed adjacent the side surface.

16. The machine according to claim 15, wherein a passage surface of the movable portion is disposed spaced apart from the side surface.

17. The machine according to claim 14, wherein the axis is positioned below a passage surface of the movable portion.

18. The machine according to claim 14, wherein the movable portion is mounted on the axis via an elastic bearing.

19. The machine according to claim 14, wherein the movable portion is pivotable from a horizontal position disposed generally orthogonal to the side surface towards the side surface.

20. The machine according to claim 14, wherein the movable portion includes at least one arm extending away from the movable portion and configured to be attached to a frame mounted to the side surface, andthe at least one arm is generally inclined relative to the movable portion.