Work machine

Abstract

A hydraulic excavator (1) includes a lower travelling body (2), an upper slewing body (3) slewably provided on the lower travelling body (2), a cab (4) provided in a front portion of the upper slewing body (3), a hydraulic fluid tank (10) provided behind the cab (4) on the upper slewing body (3), a first ascending and descending step (21) and a second ascending and descending step (22) to a top of the hydraulic fluid tank (10) which are provided between a rear surface (4a) of the cab (4) and a front surface (10a) of the hydraulic fluid tank (10).

Description

Technical Field

[0001] The present invention relates to a working machine such as a hydraulic excavator, a hydraulic crane, and a civil engineering machine, more specifically a working machine including a lower travelling body, an upper slewing body, and a hydraulic fluid tank.Background Art

[0002] There has been conventionally known a working machine provided with a maintenance deck on an upper portion of an upper slewing body to do maintenance of various components on the upper slewing body (see Patent Literature 1, for example). The working machine includes an ascending and descending step for reaching the maintenance deck from a side of the upper slewing body.

[0003] Further, there has been known a working machine including a catwalk on a left side of an upper slewing body and a ladder allowing an operator on the catwalk to reach a top surface of a hydraulic fluid tank (see Patent Literature 2, for example).

[0004] Since the working machine of Patent Literature 1 is relatively small and the maintenance deck is in an upper central portion of the upper slewing body, the maintenance deck can be easily accessed from the ascending and descending step. However, in the case of a relatively large working machine such as the working machine of Patent Literature 2, since the maintenance deck is arranged at a rearward position of an upper central portion of the upper slewing body, the maintenance deck cannot be directly accessed from the ascending and descending step.

[0005] Further, the working machine of Patent Literature 2 is relatively large. A ladder is protrusively provided on a left side surface of a hydraulic fluid tank. Since the ladder protrudes more leftward than the hydraulic fluid tank, the ladder is liable to hinder travelling and slewing of the working machine. Furthermore, there is a problem that vibrations during operation cause stress concentrations in a fixing part fixing the ladder onto a side surface of the hydraulic fluid tank, consequently leading to fracture of the fixing part.Citation List Patent Literature

[0006] Patent Literature 1: Japanese Unexamined Patent Publication No. 2013-249670 Patent Literature 2: Japanese Unexamined Patent Publication No. 2020-105779 Summary of Invention

[0007] The present invention has been made in view of the circumstances described above, and an object thereof is to provide a configuration that is simple, hardly fractures, and allows an operator to safely and easily reach a maintenance area even when the maintenance area is arranged relatively rearward on an upper slewing body.

[0008] In order to accomplish the object, the present invention provides an ascending and descending step to a top of a hydraulic fluid tank at a proper position behind a cab.

[0009] Specifically, a working machine according to an aspect of the present invention includes a lower travelling body, an upper slewing body slewably provided on the lower travelling body, a cab provided in a front portion of the upper slewing body, a hydraulic fluid tank provided behind the cab on the upper slewing body, and an ascending and descending step to a top of the hydraulic fluid tank provided between a rear surface of the cab and a front surface of the hydraulic fluid tank.Brief Description of Drawings

[0010] FIG. 1 is an upper-front perspective view of a hydraulic excavator according to an embodiment of the present invention, an upper attachment being omitted. FIG. 2 is an upper-rear perspective view of the hydraulic excavator according to the embodiment of the present invention. FIG. 3 is a side view showing an operator climbing a side of the hydraulic excavator to a catwalk. FIG. 4 is a side view showing the operator climbing an ascending and descending step. FIG. 5 is a side view showing the operator moving onto a top surface of a hydraulic tank from the ascending and descending step. FIG. 6 is an enlarged side view of the ascending and descending step, a first handrail, a second handrail, and their surroundings. FIG. 7 is an enlarged upper-front perspective view of the ascending and descending step, the first handrail, the second handrail, and their surroundings. FIG. 8 is an upper-rear perspective view of the ascending and descending step, the first handrail, the second handrail, and their surroundings. Description of Embodiments

[0011] Hereinafter, an embodiment of the present invention is described on the basis of the drawings.

[0012] FIGS. 1 to 3 show a hydraulic excavator 1 of a relatively large size as a working machine according to the embodiment of the present invention. The hydraulic excavator 1 includes a lower travelling body 2 of a crawler type, for example. Although the lower travelling body 2 has a hydraulic drive system in this embodiment, the lower travelling body 2 may have an electric drive system depending on circumstances. The lower travelling body 2 may be of a wheel type instead of the crawler type. In the description of the embodiment, upward, downward, forward, rearward, leftward, and rightward are as shown in FIG. 1.

[0013] Although not shown in the drawings in details, the lower travelling body 2 includes a slewing bearing in an upper central portion. An upper slewing body 3 is slewably supported via the slewing bearing.

[0014] Although not shown in the drawings in details, the upper slewing body 3 includes a slewing frame 3a constructed by a plate work. The slewing frame 3a has a front portion formed with an attachment mount part 3b. The attachment mount part 3b is tiltably attached with an attachment including a working device such as unillustrated bucket or civil engineering tool.

[0015] The upper slewing body 3 is provided with a cab 4 of a box shape on the left of the attachment mount part 3b. The upper slewing body 3 has a counterweight 5 at a rear portion thereof.

[0016] Various components such as hydraulic components and electric components for driving the hydraulic excavator 1 are provided between a location where the attachment mount part 3b and the cab 4 lie and a location where the counterweight 5 lies.

[0017] Specifically, an engine chamber 6 is provided in a forward middle of the counterweight 5. The engine chamber 6 accommodates therein an engine that is a drive source. The engine chamber 6 is provided with a hood 6a at a top surface thereof, and can be opened for maintenance of the engine by lifting the hood 6a rearward. An air intake chamber 7 for taking air into the engine is provided on the left of the engine chamber 6. On the right of the engine chamber 6 is provided a pump chamber 8 accommodating hydraulic components including a hydraulic pump connected to the engine. A machine chamber 9 is provided in front of the pump chamber 8. The arrangement of various components is not limited thereto. For example, the mutual arranging positions may be changed in a way of a widthwise replacement.

[0018] A hydraulic fluid tank 10 having a rectangular parallelepiped box shape is provided in front of the air intake chamber 7. A fuel tank 11 is provided in front of the machine chamber 9. Various hydraulic components 12 are provided on the right of the hydraulic fluid tank 10 and slightly behind the center of the upper slewing body 3 in a plan view. The hydraulic components 12 are provided in a location that is behind an ascending and descending step 21 to be described later and overlaps the hydraulic fluid tank 10 in a side view of the upper slewing body 3. The hydraulic components 12 are covered from above by a top board 13 including a grating plate, for example. The top board 13 serves as a maintenance deck allowing an operator to stand thereon to perform a maintenance work of components in the engine chamber 6, components in the machine chamber 9, various hydraulic components 12, and the like. In other words, the top board 13 makes a maintenance space thereabove.

[0019] As shown in FIG. 6 and FIG. 7, the top board 13 serving as the maintenance deck is arranged at a position overlapping with the top of the hydraulic fluid tank 10 in the side view of the upper slewing body 3. In other words, the top board (maintenance deck) 13 is arranged in such a way as to be hidden by the hydraulic fluid tank 10 in the side view.

[0020] Two routes lead to the top board 13. Specifically, the routes include a first route from a side of the cab 4 and a second route from a side of the fuel tank 11. The second route is a route along which an operator leaves the cab 4, and moves to the right side of the cab 4, i.e., the side on which the fuel tank 11 is, and then reaches the top board 13. The operator taking the second route climbs a plurality of footholds 14 provided in front of the fuel tank 11 while grasping a rail 15 standing in their vicinity, and reaches the top board 13 after passing through a section of a top surface of the machine chamber 9.

[0021] The other route, i.e., the first route, is a route along which an operator reaches the top board 13 via a space between the cab 4 and the hydraulic fluid tank 10. The first route is related to an improvement of accessibility which the present invention is aimed at. Specifically, in this embodiment, a catwalk 20 extending in a front-rear direction along a side surface of the slewing frame 3a of the upper slewing body 3 is provided above the lower travelling body 2. For example, the catwalk 20 includes three footings fixedly attached to the side surface of the slewing frame 3a. As shown in FIG. 3, foot receivers 2a for receiving a foot of an operator M who intends to climb up to the catwalk 20 is protrusively provided on a side surface of the lower travelling body 2. A hand hold 4b to be grasped by a hand of the operator M who is on the foot receiver 2a is provided on a side surface of a lower front portion of the cab 4. The operator M on the catwalk 20 can reach the top board 13 via a space between the cab 4 and the hydraulic fluid tank 10. Accordingly, the first route is a route leading to the top board (maintenance deck) 13 via the space between the cab 4 and the hydraulic fluid tank 10 from the catwalk 20.

[0022] The ascending and descending step 21 is provided between a rear surface 4a of the cab 4 and a front surface 10a of the hydraulic fluid tank 10 for the operator M who takes the first route. The ascending and descending step 21 is used by the operator M to climb from the catwalk 20 onto the top of the hydraulic fluid tank 10.

[0023] As seen from enlarged views in FIGS. 6 to 8, the ascending and descending step 21 includes a plurality of steps (21a, 21b). The ascending and descending step 21 may have a desirable number of steps, e.g., two or three or greater, but has two steps in this embodiment. In other words, the ascending and descending step 21 includes a first step 21a and a second step 21b. The first step 21a, which is the lowermost step, is provided at such a position and a height that enables walking-on from the catwalk 20. The first step 21a is a relatively small rectangular parallelepiped step and serves as an auxiliary step. The second step 21b higher than the first step 21a is provided at a further inner position than the first step 21a. For example, the second step 21b is constituted by a rectangular parallelepiped battery box and includes a top surface whose area is relatively broad. It is preferable that the first step 21a and the second step 21b satisfy the JIS (Japanese Industrial Standards) provision "Safety Requirements Applicable to Stairs".

[0024] Further, as seen from enlarged view in FIG. 6, a first handrail 23 is provided on the front surface 10a of the hydraulic fluid tank 10 and extends beyond an upper surface of the ascending and descending step 21, i.e., an upper surface of the second step 21b that is higher. For example, the first handrail 23 is made by bending a steel round bar or a round pipe. The first handrail 23 has a lower end between an upper surface of the first step 21a and the upper surface of the second step 21b, and has an upper end between the upper surface of the second step 21b and a top surface 10b of the hydraulic fluid tank 10. The first handrail 23 is arranged directly above the first step 21a. The first handrail 23 is provided at such a height that enables an operator on the catwalk 20 to grasp it. In a working machine smaller than the working machine of the embodiment, a first handrail 23 may be provided at such a height that enables an operator standing on the ground to grasp it.

[0025] Further, a second handrail 24 stands on the top surface 10b of the hydraulic fluid tank 10. The second handrail 24 is provided at such a position that enables an operator on the first step 21a and the second step 21b to grasp it.

[0026] For example, the second handrail 24 is made by bending a steel round bar or a round bar into an inverted U-shape. The second handrail 24 has a front end arranged directly above the first handrail 23 or in a vicinity thereof. Specifically, in this embodiment, the second handrail 24 has the front end above and slightly behind the first handrail 23.

[0027] The first handrail 23 and the second handrail 24 are arranged inward of the side surface of the hydraulic fluid tank 10 in the top view. The first handrail 23 and the second handrail 24 are thus kept from protruding beyond the side surface of the hydraulic fluid tank 10. This keeps the handrails 23, 24 from hindering travelling and slewing of the hydraulic excavator 1. Further, unlike a configuration including a ladder fixedly attached to a side surface of the hydraulic fluid tank 10, this configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part of the ladder and consequently lead to fracture of the fixing part.

[0028] As shown in FIGS. 6 to 8, the second handrail 24 includes an upper portion 24a that horizontally extends in the front-rear direction at a position upwardly away from the top surface 10b of the hydraulic fluid tank 10. The upper portion 24a serves to prevent an operator on the top surface 10b of the hydraulic fluid tank 10 from falling down. The upper portion 24a serves as "fall prevention portion" of the present invention.Access to maintenance area

[0029] Next, an access to the maintenance area in the hydraulic excavator 1 of the embodiment is described.

[0030] An access via the first route from the side of the cab 4, rather than the second route from the side of the fuel tank 11, is described herein with reference to the drawings.

[0031] As shown in FIG. 3, the operator M first climbs to the catwalk 20 by placing a foot on the foot receiver 2a protruding from the side surface of the lower travelling body 2 and grasping by a hand the hand hold 4b provided on the side surface of the lower portion of the cab 4.

[0032] Further, after moving rearward on the catwalk 20, the operator M ascends the ascending and descending step 21 while grasping the first handrail 23 as shown in FIG. 4. In other words, the operator M ascends the ascending and descending step 21 upwardly by first walking on the first step 21a and then walking on the second step 21b.

[0033] In this manner, the operator M can safely and securely perform an action of ascending the ascending and descending step 21 from the catwalk 20 by using the first step 21a, which is lower and auxiliary, as a foothold. Further, the operator M can safely ascend the ascending and descending step 21 while grasping the first handrail 23. Similarly, the first step 21a and the first handrail 23 can be effectively used when the operator M descends the ascending and descending step 21.

[0034] In a case of a working machine that is smaller than the working machine of the present embodiment and includes no catwalk 20, the first handrail 23 may be used when an operator ascends the ascending and descending step 21 from the ground or descends the ascending and descending step 21.

[0035] The operator M who has ascended the ascending and descending step 21 in the manner described above further climbs up to the top surface 10b of the hydraulic fluid tank 10 while grasping the second handrail 24 as shown in FIG. 5. Accordingly, grasping of the second handrail 24 facilitates a movement of the operator M from the ascending and descending step 21 onto the top surface 10b of the hydraulic fluid tank 10, which is at a considerably high position from the ground.

[0036] In this moment, the operator M on the top surface 10b is liable to be frightened since the top surface 10b of the hydraulic fluid tank 10 is at the considerably high position from the ground. In the embodiment, however, the second handrail 24 including the upper portion 24a extending in the front-rear direction stands on the top surface 10b. Therefore, the operator M can use the upper portion 24a as a handrail when climbing up to the top surface 10b. Similarly, the upper portion 24a may be used as a handrail when an operator climbs down from the top surface 10b. Therefore, the operator M can climb up to and down from the top surface 10b of the hydraulic fluid tank 10 without being frightened.

[0037] The operator M having reached the top surface 10b of the hydraulic fluid tank 10 in the manner described above moves on the top board 13 serving as the maintenance deck from the top surface 10b of the hydraulic fluid tank 10. This completes the access to the maintenance area above the top board 13. In this state, the operator M can do the maintenance of various components of the hydraulic excavator 1 from the top board 13.

[0038] Accordingly, in this embodiment, the operator M can reach the top (top surface 10b) of the hydraulic fluid tank 10 while grasping the second handrail 24 after ascending the ascending and descending step 21 while grasping the first handrail 23. In other words, the operator M can safely and securely reach the top of the hydraulic fluid tank 10 to do maintenance by using the ascending and descending step 21, the first handrail 23, and the second handrail 24 that are provided along the first route on the side of the cab 4.

[0039] Specifically, the operator M can reach the top of the hydraulic fluid tank 10 from the side of the upper slewing body 3 by using the first step 21a and the second step 21b of the ascending and descending step 21. Accordingly, the operator M can safely and securely access the top board (maintenance deck) 13 in the upper portion of the upper slewing body 3 from the top of the hydraulic fluid tank 10.

[0040] In particular, even in the case of the relatively large hydraulic excavator 1 provided with the top board (maintenance deck) 13 at a position behind the center of the upper portion of the upper slewing body 3 as in the embodiment, the operator M can safely and securely access the top board 13 by using the ascending and descending step 21 (the first step 21a and the second step 21b).

[0041] Therefore, the hydraulic excavator 1 according to the embodiment enables the operator M to safely and easily reach the maintenance area in a simple configuration.Other embodiments

[0042] The present invention may be embodied as follows instead of the embodiment described above.

[0043] In the embodiment, the working machine includes the hydraulic excavator 1 that is relatively large and is of the crawler type. However, the working machine may include a hydraulic crane or a hydraulic civil engineering machine of the crawler type, or a hydraulic excavator, a hydraulic crane, or a hydraulic civil engineering machine of the wheel type.

[0044] It should be noted that the embodiments are essentially preferable examples and are not meant to delimit the scope of the present invention, things and use to which the present invention is applied.Summary

[0045] A working machine according to a first configuration of the present invention includes a lower travelling body, an upper slewing body slewably provided on the lower travelling body, a cab provided in a front portion of the upper slewing body, a hydraulic fluid tank provided behind the cab on the upper slewing body, and an ascending and descending step to a top of the hydraulic fluid tank provided between a rear surface of the cab and a front surface of the hydraulic fluid tank.

[0046] The first configuration allows an operator to reach the top of the hydraulic fluid tank from a side of the upper slewing body by using the ascending and descending step. Therefore, the maintenance deck can be safely and securely reached from the top of the hydraulic fluid tank even when the maintenance deck lies relatively rearward over an upper portion of the upper slewing body. Further, since the configuration eliminates the need for a ladder as in Patent Literature 2 which protrudes from a side surface of the hydraulic fluid tank, the configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part fixing the ladder onto the side surface of the hydraulic fluid tank and consequently lead to fracture of the fixing part.

[0047] In the working machine according to a second configuration, in the first configuration, the working machine further includes a first handrail provided on the front surface of the hydraulic fluid tank and extending beyond an upper surface of the ascending and descending step.

[0048] The second configuration makes it possible to safely ascend and descend the ascending and descending step while grasping the first handrail.

[0049] In the working machine according to a third configuration, in the second configuration, the working machine further includes a catwalk provided on a side surface of the upper slewing body and extending in a front-rear direction along the upper slewing body, wherein the first handrail is provided at such a height that enables an operator on the catwalk to grasp it.

[0050] The third configuration makes it possible to safely and securely perform, while grasping the first handrail, an action of ascending the ascending and descending step from the catwalk or an action of descending the ascending and descending step.

[0051] In the working machine according to a fourth configuration, in any one of the first to third configurations, the ascending and descending step includes a plurality of steps having a lowermost step provided at such a position and a height that enables walking-on from the catwalk.

[0052] The configuration makes it possible to safely and securely perform, by using the lowermost step of the ascending and descending step, the action of ascending the ascending and descending step from the catwalk or the action of descending the ascending and descending step.

[0053] In the working machine according to a fifth configuration, in the second configuration, the working machine further includes a second handrail standing on the top surface of the hydraulic fluid tank, wherein the second handrail is provided at such a position that enables an operator on the ascending and descending step to grasp it.

[0054] In the fifth configuration, grasping of the second handrail allows the operator to safely climb from the ascending and descending step onto the top of the hydraulic fluid tank, which is at a considerably high position from the ground.

[0055] In the working machine according to a sixth configuration, in the fifth configuration, the second handrail has a front end arranged directly above the first handrail or in a vicinity thereof.

[0056] The sixth configuration allows an operator having ascended the ascending and descending step by grasping the first handrail to safely and securely climb up, by grasping the second handrail, to the top of the hydraulic fluid tank from a position on the ascending and descending step at which the operator stands.

[0057] In the working machine according to a seventh configuration, in the fifth configuration or the sixth configuration, the first handrail and the second handrail are arranged inward of a side surface of the hydraulic fluid tank in a top view.

[0058] In the seventh configuration, the first handrail and the second handrail are kept from protruding beyond the side surface of the hydraulic fluid tank. This keeps the handrails from hindering travelling and slewing of the working machine. Further, unlike a configuration including a ladder fixedly attached to a side surface of the hydraulic fluid tank, this configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part of the ladder and consequently lead to fracture of the fixing part.

[0059] In the working machine according to an eighth configuration, in any one of the fifth to seventh configurations, the second handrail includes a fall prevention portion extending in the front-rear direction for preventing an operator on the top surface of the hydraulic fluid tank from falling down.

[0060] The eighth configuration allows the operator having reached the top surface of the hydraulic fluid tank to use the fall prevention portion of the second handrail as a handrail. The operator can thus climb up to and down from the top surface of the hydraulic fluid tank, which is at the considerably high position from the ground, without being frightened.

Examples

Embodiment Construction

[0011]Hereinafter, an embodiment of the present invention is described on the basis of the drawings.

[0012]FIGS. 1 to 3 show a hydraulic excavator 1 of a relatively large size as a working machine according to the embodiment of the present invention. The hydraulic excavator 1 includes a lower travelling body 2 of a crawler type, for example. Although the lower travelling body 2 has a hydraulic drive system in this embodiment, the lower travelling body 2 may have an electric drive system depending on circumstances. The lower travelling body 2 may be of a wheel type instead of the crawler type. In the description of the embodiment, upward, downward, forward, rearward, leftward, and rightward are as shown in FIG. 1.

[0013]Although not shown in the drawings in details, the lower travelling body 2 includes a slewing bearing in an upper central portion. An upper slewing body 3 is slewably supported via the slewing bearing.

[0014]Although not shown in the drawings in details, the upper slewin...

Technical Field

[0001] The present invention relates to a working machine such as a hydraulic excavator, a hydraulic crane, and a civil engineering machine, more specifically a working machine including a lower travelling body, an upper slewing body, and a hydraulic fluid tank.Background Art

[0002] There has been conventionally known a working machine provided with a maintenance deck on an upper portion of an upper slewing body to do maintenance of various components on the upper slewing body (see Patent Literature 1, for example). The working machine includes an ascending and descending step for reaching the maintenance deck from a side of the upper slewing body.

[0003] Further, there has been known a working machine including a catwalk on a left side of an upper slewing body and a ladder allowing an operator on the catwalk to reach a top surface of a hydraulic fluid tank (see Patent Literature 2, for example).

[0004] Since the working machine of Patent Literature 1 is relatively small and the maintenance deck is in an upper central portion of the upper slewing body, the maintenance deck can be easily accessed from the ascending and descending step. However, in the case of a relatively large working machine such as the working machine of Patent Literature 2, since the maintenance deck is arranged at a rearward position of an upper central portion of the upper slewing body, the maintenance deck cannot be directly accessed from the ascending and descending step.

[0005] Further, the working machine of Patent Literature 2 is relatively large. A ladder is protrusively provided on a left side surface of a hydraulic fluid tank. Since the ladder protrudes more leftward than the hydraulic fluid tank, the ladder is liable to hinder travelling and slewing of the working machine. Furthermore, there is a problem that vibrations during operation cause stress concentrations in a fixing part fixing the ladder onto a side surface of the hydraulic fluid tank, consequently leading to fracture of the fixing part.Citation List Patent Literature

[0006] Patent Literature 1: Japanese Unexamined Patent Publication No. 2013-249670 Patent Literature 2: Japanese Unexamined Patent Publication No. 2020-105779 Summary of Invention

[0007] The present invention has been made in view of the circumstances described above, and an object thereof is to provide a configuration that is simple, hardly fractures, and allows an operator to safely and easily reach a maintenance area even when the maintenance area is arranged relatively rearward on an upper slewing body.

[0008] In order to accomplish the object, the present invention provides an ascending and descending step to a top of a hydraulic fluid tank at a proper position behind a cab.

[0009] Specifically, a working machine according to an aspect of the present invention includes a lower travelling body, an upper slewing body slewably provided on the lower travelling body, a cab provided in a front portion of the upper slewing body, a hydraulic fluid tank provided behind the cab on the upper slewing body, and an ascending and descending step to a top of the hydraulic fluid tank provided between a rear surface of the cab and a front surface of the hydraulic fluid tank.Brief Description of Drawings

[0010] FIG. 1 is an upper-front perspective view of a hydraulic excavator according to an embodiment of the present invention, an upper attachment being omitted. FIG. 2 is an upper-rear perspective view of the hydraulic excavator according to the embodiment of the present invention. FIG. 3 is a side view showing an operator climbing a side of the hydraulic excavator to a catwalk. FIG. 4 is a side view showing the operator climbing an ascending and descending step. FIG. 5 is a side view showing the operator moving onto a top surface of a hydraulic tank from the ascending and descending step. FIG. 6 is an enlarged side view of the ascending and descending step, a first handrail, a second handrail, and their surroundings. FIG. 7 is an enlarged upper-front perspective view of the ascending and descending step, the first handrail, the second handrail, and their surroundings. FIG. 8 is an upper-rear perspective view of the ascending and descending step, the first handrail, the second handrail, and their surroundings. Description of Embodiments

[0011] Hereinafter, an embodiment of the present invention is described on the basis of the drawings.

[0012] FIGS. 1 to 3 show a hydraulic excavator 1 of a relatively large size as a working machine according to the embodiment of the present invention. The hydraulic excavator 1 includes a lower travelling body 2 of a crawler type, for example. Although the lower travelling body 2 has a hydraulic drive system in this embodiment, the lower travelling body 2 may have an electric drive system depending on circumstances. The lower travelling body 2 may be of a wheel type instead of the crawler type. In the description of the embodiment, upward, downward, forward, rearward, leftward, and rightward are as shown in FIG. 1.

[0013] Although not shown in the drawings in details, the lower travelling body 2 includes a slewing bearing in an upper central portion. An upper slewing body 3 is slewably supported via the slewing bearing.

[0014] Although not shown in the drawings in details, the upper slewing body 3 includes a slewing frame 3a constructed by a plate work. The slewing frame 3a has a front portion formed with an attachment mount part 3b. The attachment mount part 3b is tiltably attached with an attachment including a working device such as unillustrated bucket or civil engineering tool.

[0015] The upper slewing body 3 is provided with a cab 4 of a box shape on the left of the attachment mount part 3b. The upper slewing body 3 has a counterweight 5 at a rear portion thereof.

[0016] Various components such as hydraulic components and electric components for driving the hydraulic excavator 1 are provided between a location where the attachment mount part 3b and the cab 4 lie and a location where the counterweight 5 lies.

[0017] Specifically, an engine chamber 6 is provided in a forward middle of the counterweight 5. The engine chamber 6 accommodates therein an engine that is a drive source. The engine chamber 6 is provided with a hood 6a at a top surface thereof, and can be opened for maintenance of the engine by lifting the hood 6a rearward. An air intake chamber 7 for taking air into the engine is provided on the left of the engine chamber 6. On the right of the engine chamber 6 is provided a pump chamber 8 accommodating hydraulic components including a hydraulic pump connected to the engine. A machine chamber 9 is provided in front of the pump chamber 8. The arrangement of various components is not limited thereto. For example, the mutual arranging positions may be changed in a way of a widthwise replacement.

[0018] A hydraulic fluid tank 10 having a rectangular parallelepiped box shape is provided in front of the air intake chamber 7. A fuel tank 11 is provided in front of the machine chamber 9. Various hydraulic components 12 are provided on the right of the hydraulic fluid tank 10 and slightly behind the center of the upper slewing body 3 in a plan view. The hydraulic components 12 are provided in a location that is behind an ascending and descending step 21 to be described later and overlaps the hydraulic fluid tank 10 in a side view of the upper slewing body 3. The hydraulic components 12 are covered from above by a top board 13 including a grating plate, for example. The top board 13 serves as a maintenance deck allowing an operator to stand thereon to perform a maintenance work of components in the engine chamber 6, components in the machine chamber 9, various hydraulic components 12, and the like. In other words, the top board 13 makes a maintenance space thereabove.

[0019] As shown in FIG. 6 and FIG. 7, the top board 13 serving as the maintenance deck is arranged at a position overlapping with the top of the hydraulic fluid tank 10 in the side view of the upper slewing body 3. In other words, the top board (maintenance deck) 13 is arranged in such a way as to be hidden by the hydraulic fluid tank 10 in the side view.

[0020] Two routes lead to the top board 13. Specifically, the routes include a first route from a side of the cab 4 and a second route from a side of the fuel tank 11. The second route is a route along which an operator leaves the cab 4, and moves to the right side of the cab 4, i.e., the side on which the fuel tank 11 is, and then reaches the top board 13. The operator taking the second route climbs a plurality of footholds 14 provided in front of the fuel tank 11 while grasping a rail 15 standing in their vicinity, and reaches the top board 13 after passing through a section of a top surface of the machine chamber 9.

[0021] The other route, i.e., the first route, is a route along which an operator reaches the top board 13 via a space between the cab 4 and the hydraulic fluid tank 10. The first route is related to an improvement of accessibility which the present invention is aimed at. Specifically, in this embodiment, a catwalk 20 extending in a front-rear direction along a side surface of the slewing frame 3a of the upper slewing body 3 is provided above the lower travelling body 2. For example, the catwalk 20 includes three footings fixedly attached to the side surface of the slewing frame 3a. As shown in FIG. 3, foot receivers 2a for receiving a foot of an operator M who intends to climb up to the catwalk 20 is protrusively provided on a side surface of the lower travelling body 2. A hand hold 4b to be grasped by a hand of the operator M who is on the foot receiver 2a is provided on a side surface of a lower front portion of the cab 4. The operator M on the catwalk 20 can reach the top board 13 via a space between the cab 4 and the hydraulic fluid tank 10. Accordingly, the first route is a route leading to the top board (maintenance deck) 13 via the space between the cab 4 and the hydraulic fluid tank 10 from the catwalk 20.

[0022] The ascending and descending step 21 is provided between a rear surface 4a of the cab 4 and a front surface 10a of the hydraulic fluid tank 10 for the operator M who takes the first route. The ascending and descending step 21 is used by the operator M to climb from the catwalk 20 onto the top of the hydraulic fluid tank 10.

[0023] As seen from enlarged views in FIGS. 6 to 8, the ascending and descending step 21 includes a plurality of steps (21a, 21b). The ascending and descending step 21 may have a desirable number of steps, e.g., two or three or greater, but has two steps in this embodiment. In other words, the ascending and descending step 21 includes a first step 21a and a second step 21b. The first step 21a, which is the lowermost step, is provided at such a position and a height that enables walking-on from the catwalk 20. The first step 21a is a relatively small rectangular parallelepiped step and serves as an auxiliary step. The second step 21b higher than the first step 21a is provided at a further inner position than the first step 21a. For example, the second step 21b is constituted by a rectangular parallelepiped battery box and includes a top surface whose area is relatively broad. It is preferable that the first step 21a and the second step 21b satisfy the JIS (Japanese Industrial Standards) provision "Safety Requirements Applicable to Stairs".

[0024] Further, as seen from enlarged view in FIG. 6, a first handrail 23 is provided on the front surface 10a of the hydraulic fluid tank 10 and extends beyond an upper surface of the ascending and descending step 21, i.e., an upper surface of the second step 21b that is higher. For example, the first handrail 23 is made by bending a steel round bar or a round pipe. The first handrail 23 has a lower end between an upper surface of the first step 21a and the upper surface of the second step 21b, and has an upper end between the upper surface of the second step 21b and a top surface 10b of the hydraulic fluid tank 10. The first handrail 23 is arranged directly above the first step 21a. The first handrail 23 is provided at such a height that enables an operator on the catwalk 20 to grasp it. In a working machine smaller than the working machine of the embodiment, a first handrail 23 may be provided at such a height that enables an operator standing on the ground to grasp it.

[0025] Further, a second handrail 24 stands on the top surface 10b of the hydraulic fluid tank 10. The second handrail 24 is provided at such a position that enables an operator on the first step 21a and the second step 21b to grasp it.

[0026] For example, the second handrail 24 is made by bending a steel round bar or a round bar into an inverted U-shape. The second handrail 24 has a front end arranged directly above the first handrail 23 or in a vicinity thereof. Specifically, in this embodiment, the second handrail 24 has the front end above and slightly behind the first handrail 23.

[0027] The first handrail 23 and the second handrail 24 are arranged inward of the side surface of the hydraulic fluid tank 10 in the top view. The first handrail 23 and the second handrail 24 are thus kept from protruding beyond the side surface of the hydraulic fluid tank 10. This keeps the handrails 23, 24 from hindering travelling and slewing of the hydraulic excavator 1. Further, unlike a configuration including a ladder fixedly attached to a side surface of the hydraulic fluid tank 10, this configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part of the ladder and consequently lead to fracture of the fixing part.

[0028] As shown in FIGS. 6 to 8, the second handrail 24 includes an upper portion 24a that horizontally extends in the front-rear direction at a position upwardly away from the top surface 10b of the hydraulic fluid tank 10. The upper portion 24a serves to prevent an operator on the top surface 10b of the hydraulic fluid tank 10 from falling down. The upper portion 24a serves as "fall prevention portion" of the present invention.Access to maintenance area

[0029] Next, an access to the maintenance area in the hydraulic excavator 1 of the embodiment is described.

[0030] An access via the first route from the side of the cab 4, rather than the second route from the side of the fuel tank 11, is described herein with reference to the drawings.

[0031] As shown in FIG. 3, the operator M first climbs to the catwalk 20 by placing a foot on the foot receiver 2a protruding from the side surface of the lower travelling body 2 and grasping by a hand the hand hold 4b provided on the side surface of the lower portion of the cab 4.

[0032] Further, after moving rearward on the catwalk 20, the operator M ascends the ascending and descending step 21 while grasping the first handrail 23 as shown in FIG. 4. In other words, the operator M ascends the ascending and descending step 21 upwardly by first walking on the first step 21a and then walking on the second step 21b.

[0033] In this manner, the operator M can safely and securely perform an action of ascending the ascending and descending step 21 from the catwalk 20 by using the first step 21a, which is lower and auxiliary, as a foothold. Further, the operator M can safely ascend the ascending and descending step 21 while grasping the first handrail 23. Similarly, the first step 21a and the first handrail 23 can be effectively used when the operator M descends the ascending and descending step 21.

[0034] In a case of a working machine that is smaller than the working machine of the present embodiment and includes no catwalk 20, the first handrail 23 may be used when an operator ascends the ascending and descending step 21 from the ground or descends the ascending and descending step 21.

[0035] The operator M who has ascended the ascending and descending step 21 in the manner described above further climbs up to the top surface 10b of the hydraulic fluid tank 10 while grasping the second handrail 24 as shown in FIG. 5. Accordingly, grasping of the second handrail 24 facilitates a movement of the operator M from the ascending and descending step 21 onto the top surface 10b of the hydraulic fluid tank 10, which is at a considerably high position from the ground.

[0036] In this moment, the operator M on the top surface 10b is liable to be frightened since the top surface 10b of the hydraulic fluid tank 10 is at the considerably high position from the ground. In the embodiment, however, the second handrail 24 including the upper portion 24a extending in the front-rear direction stands on the top surface 10b. Therefore, the operator M can use the upper portion 24a as a handrail when climbing up to the top surface 10b. Similarly, the upper portion 24a may be used as a handrail when an operator climbs down from the top surface 10b. Therefore, the operator M can climb up to and down from the top surface 10b of the hydraulic fluid tank 10 without being frightened.

[0037] The operator M having reached the top surface 10b of the hydraulic fluid tank 10 in the manner described above moves on the top board 13 serving as the maintenance deck from the top surface 10b of the hydraulic fluid tank 10. This completes the access to the maintenance area above the top board 13. In this state, the operator M can do the maintenance of various components of the hydraulic excavator 1 from the top board 13.

[0038] Accordingly, in this embodiment, the operator M can reach the top (top surface 10b) of the hydraulic fluid tank 10 while grasping the second handrail 24 after ascending the ascending and descending step 21 while grasping the first handrail 23. In other words, the operator M can safely and securely reach the top of the hydraulic fluid tank 10 to do maintenance by using the ascending and descending step 21, the first handrail 23, and the second handrail 24 that are provided along the first route on the side of the cab 4.

[0039] Specifically, the operator M can reach the top of the hydraulic fluid tank 10 from the side of the upper slewing body 3 by using the first step 21a and the second step 21b of the ascending and descending step 21. Accordingly, the operator M can safely and securely access the top board (maintenance deck) 13 in the upper portion of the upper slewing body 3 from the top of the hydraulic fluid tank 10.

[0040] In particular, even in the case of the relatively large hydraulic excavator 1 provided with the top board (maintenance deck) 13 at a position behind the center of the upper portion of the upper slewing body 3 as in the embodiment, the operator M can safely and securely access the top board 13 by using the ascending and descending step 21 (the first step 21a and the second step 21b).

[0041] Therefore, the hydraulic excavator 1 according to the embodiment enables the operator M to safely and easily reach the maintenance area in a simple configuration.Other embodiments

[0042] The present invention may be embodied as follows instead of the embodiment described above.

[0043] In the embodiment, the working machine includes the hydraulic excavator 1 that is relatively large and is of the crawler type. However, the working machine may include a hydraulic crane or a hydraulic civil engineering machine of the crawler type, or a hydraulic excavator, a hydraulic crane, or a hydraulic civil engineering machine of the wheel type.

[0044] It should be noted that the embodiments are essentially preferable examples and are not meant to delimit the scope of the present invention, things and use to which the present invention is applied.Summary

[0045] A working machine according to a first configuration of the present invention includes a lower travelling body, an upper slewing body slewably provided on the lower travelling body, a cab provided in a front portion of the upper slewing body, a hydraulic fluid tank provided behind the cab on the upper slewing body, and an ascending and descending step to a top of the hydraulic fluid tank provided between a rear surface of the cab and a front surface of the hydraulic fluid tank.

[0046] The first configuration allows an operator to reach the top of the hydraulic fluid tank from a side of the upper slewing body by using the ascending and descending step. Therefore, the maintenance deck can be safely and securely reached from the top of the hydraulic fluid tank even when the maintenance deck lies relatively rearward over an upper portion of the upper slewing body. Further, since the configuration eliminates the need for a ladder as in Patent Literature 2 which protrudes from a side surface of the hydraulic fluid tank, the configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part fixing the ladder onto the side surface of the hydraulic fluid tank and consequently lead to fracture of the fixing part.

[0047] In the working machine according to a second configuration, in the first configuration, the working machine further includes a first handrail provided on the front surface of the hydraulic fluid tank and extending beyond an upper surface of the ascending and descending step.

[0048] The second configuration makes it possible to safely ascend and descend the ascending and descending step while grasping the first handrail.

[0049] In the working machine according to a third configuration, in the second configuration, the working machine further includes a catwalk provided on a side surface of the upper slewing body and extending in a front-rear direction along the upper slewing body, wherein the first handrail is provided at such a height that enables an operator on the catwalk to grasp it.

[0050] The third configuration makes it possible to safely and securely perform, while grasping the first handrail, an action of ascending the ascending and descending step from the catwalk or an action of descending the ascending and descending step.

[0051] In the working machine according to a fourth configuration, in any one of the first to third configurations, the ascending and descending step includes a plurality of steps having a lowermost step provided at such a position and a height that enables walking-on from the catwalk.

[0052] The configuration makes it possible to safely and securely perform, by using the lowermost step of the ascending and descending step, the action of ascending the ascending and descending step from the catwalk or the action of descending the ascending and descending step.

[0053] In the working machine according to a fifth configuration, in the second configuration, the working machine further includes a second handrail standing on the top surface of the hydraulic fluid tank, wherein the second handrail is provided at such a position that enables an operator on the ascending and descending step to grasp it.

[0054] In the fifth configuration, grasping of the second handrail allows the operator to safely climb from the ascending and descending step onto the top of the hydraulic fluid tank, which is at a considerably high position from the ground.

[0055] In the working machine according to a sixth configuration, in the fifth configuration, the second handrail has a front end arranged directly above the first handrail or in a vicinity thereof.

[0056] The sixth configuration allows an operator having ascended the ascending and descending step by grasping the first handrail to safely and securely climb up, by grasping the second handrail, to the top of the hydraulic fluid tank from a position on the ascending and descending step at which the operator stands.

[0057] In the working machine according to a seventh configuration, in the fifth configuration or the sixth configuration, the first handrail and the second handrail are arranged inward of a side surface of the hydraulic fluid tank in a top view.

[0058] In the seventh configuration, the first handrail and the second handrail are kept from protruding beyond the side surface of the hydraulic fluid tank. This keeps the handrails from hindering travelling and slewing of the working machine. Further, unlike a configuration including a ladder fixedly attached to a side surface of the hydraulic fluid tank, this configuration can avoid the problem that vibrations during operation cause stress concentrations in a fixing part of the ladder and consequently lead to fracture of the fixing part.

[0059] In the working machine according to an eighth configuration, in any one of the fifth to seventh configurations, the second handrail includes a fall prevention portion extending in the front-rear direction for preventing an operator on the top surface of the hydraulic fluid tank from falling down.

[0060] The eighth configuration allows the operator having reached the top surface of the hydraulic fluid tank to use the fall prevention portion of the second handrail as a handrail. The operator can thus climb up to and down from the top surface of the hydraulic fluid tank, which is at the considerably high position from the ground, without being frightened.

Examples

Embodiment Construction

[0011]Hereinafter, an embodiment of the present invention is described on the basis of the drawings.

[0012]FIGS. 1 to 3 show a hydraulic excavator 1 of a relatively large size as a working machine according to the embodiment of the present invention. The hydraulic excavator 1 includes a lower travelling body 2 of a crawler type, for example. Although the lower travelling body 2 has a hydraulic drive system in this embodiment, the lower travelling body 2 may have an electric drive system depending on circumstances. The lower travelling body 2 may be of a wheel type instead of the crawler type. In the description of the embodiment, upward, downward, forward, rearward, leftward, and rightward are as shown in FIG. 1.

[0013]Although not shown in the drawings in details, the lower travelling body 2 includes a slewing bearing in an upper central portion. An upper slewing body 3 is slewably supported via the slewing bearing.

[0014]Although not shown in the drawings in details, the upper slewin...

Claims

1. A working machine comprising: a lower travelling body; an upper slewing body slewably provided on the lower travelling body; a cab provided in a front portion of the upper slewing body; a hydraulic fluid tank provided behind the cab on the upper slewing body; and an ascending and descending step to a top of the hydraulic fluid tank provided between a rear surface of the cab and a front surface of the hydraulic fluid tank.

2. The working machine according to claim 1, further comprising: a first handrail provided on the front surface of the hydraulic fluid tank and extending beyond an upper surface of the ascending and descending step.

3. The working machine according to claim 2, further comprising: a catwalk provided on a side surface of the upper slewing body and extending in a front-rear direction along the upper slewing body, wherein the first handrail is provided at such a height that enables an operator on the catwalk to grasp it.

4. The working machine according to claim 3, wherein the ascending and descending step includes a plurality of steps having a lowermost step provided at such a position and a height that enables walking-on from the catwalk.

5. The working machine according to claim 2, further comprising: a second handrail standing on a top surface of the hydraulic fluid tank, wherein the second handrail is provided at such a position that enables an operator on the ascending and descending step to grasp it.

6. The working machine according to claim 5, wherein the second handrail has a front end arranged directly above the first handrail or in a vicinity thereof.

7. The working machine according to claim 5, wherein the first handrail and the second handrail are arranged inward of a side surface of the hydraulic fluid tank in a top view.

8. The working machine according to any one of claims 5 to 7, wherein the second handrail includes a fall prevention portion extending in a front-rear direction for preventing an operator on the top surface of the hydraulic fluid tank from falling down.

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