EP2423393A1

EP2423393A1 - Cab protection structure for construction machinery

Info

Publication number: EP2423393A1
Application number: EP10766759A
Authority: EP
Inventors: Eiji Akahane; Shigeru Kojima; Makoto Hasuike; Yuichiro Tanaka; Tetsuji Takaoka; Hidetomo Ikeda; Tsuyoshi Miyakita
Original assignee: Caterpillar SARL
Current assignee: Caterpillar SARL
Priority date: 2009-04-20
Filing date: 2010-01-27
Publication date: 2012-02-29
Also published as: JP2010248846A; WO2010122696A1; EP2423393A4

Abstract

Provided is a protection device that, without being large in size, can reliably protect the cab of a hydraulic shovel, said shovel being provided with a cab on one side of a boom that is mounted on the shovel body so as to be able to swing freely up and down, in the case that the shovel rolls over toward the cab side. The top surface (4a) of the boom (4) on the hydraulic shovel (1) is provided with a protective member (10) positioned so that viewed from the side, the protective member and the boom (4) cover the front support area (5a) of the cab (5), at least when the boom (4) is lowered.

Description

TECHNICAL FIELD

The present invention relates to a cab protection structure that protects a cab of a construction machine such as a hydraulic shovel and the like in the event that a machine body of the construction machine topples.

BACKGROUND ART

A boom which is a working attachment cab be mounted to swing up and down upon a machine body in a construction machine such as a hydraulic shovel. A cab can be adjacently mounted at one side in a right and left direction of the boom.
The cab is less likely to be tilted even if the machine body topples toward the boom. It is because the boom can function to protect the cab. However, the cab may directly impact to be tilted toward the boom if the machine body topples toward the cab. More specifically, the cab can be prevented from being severely tilted toward the boom if the boom is in a raised posture. It is because the boom, when viewed from a side, may overlap with an upper portion of a front supporting column and a roof portion of the cab, and therefore the boom can function as a protection member to support the upper portion of the cab. In contrast, the cab may be severely tilted if the boom is in a lowered posture. It is because the boom may overlap with only a lower portion of the front supporting column of the cab when viewed from the side, and therefore nothing may support the upper portion of the cab.
It is thus known that a truss structure is formed to function as a cab protection member in order to prevent the cab from being deformed. The truss structure is formed by using a main protection member and auxiliary protection members. A pair of main frames pivotally support a base end portion of the boom. Arranged upon one of the main frames at a side of the cab, the main protection member stands so as to project above an upper surface of the cab. Arranged upon the other main frame, the auxiliary protection members stand so as to support the main protection member.

RELATED ART DOCUMENT(S)

PATENT DOCUMENT(S)

Patent Document 1: Japanese Published Unexamined Patent Application No. 2005-350948

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

However, the above conventional protection member as a whole is huge. It is because the protection members are high enough to extend from the main frames over the cab roof, with a resulting considerable distance between the main frames and the roof portion of the cab.
Furthermore, the protection members, which stand upon the pair of main frames, have top ends connected with each other. Vibrations, which occur when the machine body travels or works, are likely to result in shaking in varying degrees corresponding to differences in a length and a mounting angle between the main protection member and the auxiliary protection members. Accordingly, a spherical bearing is installed to a bearing portion of the auxiliary protection members so as to absorb loads generated by the varying vibrations. However, this arrangement is undesirable because of a complex structure and a larger number of parts.
Furthermore, the protection members stand upon not only one of the main frames at the side of the cab but also upon the other main frame in order to secure desired strength. However, the protection member at the other main frame needs to be arranged rearward enough to be outside a swing range of the boom. The cab protection member in itself thus protects only a rear part of the cab, and therefore a front upper half portion of the cab is left unprotected especially when the boom is in a lower posture. In short, the cab is still prone to be readily tilted.
Furthermore, the protection members are provided so as to step over and bridge between the pair of the main frames. However, installation of other members and devices to the main frames must be limited because of the protection members. Workability is also significantly decreased at the time of maintenance. The problems are to be solved by the present invention.

MEANS FOR SOLVING THE PROBLEMS

The present invention has been made with the object of resolving those problems in view of the above-mentioned circumstances, and a first aspect of the present invention provides a cab protection structure in a construction machine. The construction machine includes a boom mounted upon a machine body so as to swing up and down and a cab provided at one side in a right and left direction of the boom. A protection member is provided to protect the cab in the event that the machine body topples. The protection member is provided upon the boom so as to project above an upper surface of the boom and to be positioned to overlap with a front supporting column region of the cab in a side view when the boom is at least in a lowered posture.
A second exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the first exemplary aspect, in which the protection member is mounted to at least either one of the upper surface or a side surface of the boom.
A third exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the first or second exemplary aspect, in which the protection member has at least a plate surface parallel to a side surface of the boom.
A fourth exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the first, second, or third exemplary aspect, in which the protection member includes a pair of plate members with a plate surface parallel to a side surface of the boom, the plate members being separating and facing each other, and a reinforcing member provided between the plate members.
A fifth exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the fourth exemplary aspect, in which the protection member is formed to be a gate shape with an internal space formed by the pair of plate members and the reinforcing member.
A sixth exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the first or second exemplary aspect, in which the protection member includes a cab-side plate member with a surface inclined further in a direction of being away from the cab as the plate member extends upward further, and a reinforcing member which is inclined so as to extend substantially perpendicularly from an upper end portion of the plate member to the boom.
A seventh exemplary aspect of the present invention provides the cab protection structure in the construction machine according to the fifth or sixth exemplary aspect, in which the protection member includes a pass-through portion in the internal space formed by the plate members and the reinforcing member so as to provide piping and wiring upon the upper surface of the boom through the pass-through portion.

EFFECTS OF THE INVENTION

According to the first exemplary aspect, even if the machine body topples and the boom is in the lowered posture, the protection member along with the boom support the cab by the boom upper surface so as to prevent the cab from toppling. The cab can thus be prevented from being deformed or damaged.
Furthermore, the protection member along with the boom support the cab by pressing into contact with a front supporting column portion and a roof portion of the cab. Compared with a structure in which a rear portion in the cab is supported to protect the cab, a front portion in the cab corresponding to a front of a user is protected more securely. This is excellent in safety of a user, securing a wider movable range, an easier escape from the cab, etc.
According to the second exemplary aspect, the protection member is provided upon the boom. This avoids a case in which a protection member is arranged upon an upper portion of the main frames, an apparatus is increased in size, and the boom is deteriorated by a restriction on positioning of other devices or difficulty of maintenance.
According to the third exemplary aspect, a tilted cab is supported integrally by the boom and the protection member, with a resultant reliable support for the cab.
According to the fourth exemplary aspect, the protection member reliably supports the cab because the plate members are reinforced by the reinforcing member.
According to the fifth exemplary aspect, because the reinforcing member firmly reinforces the pair of plate members without forming a wall surface, the protection member is no obstacle for other members and devices to be installed. Furthermore, an opposite side of the protection member can be seen through upon the boom, with a resultant sustainable efficient maintenance work, etc.
According to the sixth exemplary aspect, an inclined cab side surface can be supported widely by means of surface contact, with a resultant further reliable support for the cab.
According to the seventh exemplary aspect, piping and wiring which are placed through the pass-through portion are protected by the protection member even if the machine body topples. The piping and the like can thus be prevented from being damaged or fractured to leak oil due to contact with the cab in the event that the machine body topples. Furthermore, the piping and the like are provided upon the boom upper surface simply through the pass-through portion of the protection member. This prevents an obstacle to the installation upon the boom upper surface even when the protection member is mounted thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a hydraulic shovel;
FIG. 2 is a partial perspective view of a rotating body and a boom;
FIG. 3 is a partial perspective view of the boom and a protection member as in a first embodiment of the present invention;
FIG. 4 is a front view of the boom and the protection member as in the first embodiment of the present invention;
FIGS. 5A, 5B, and 5C are explanatory diagrams illustrating actions of the boom and the protection member as in the first embodiment of the present invention;
FIG. 6A is a perspective view and FIG. 6B is a front view of a boom and a protection member as in a second embodiment of the present invention; and
FIG. 7A is a perspective view and FIG. 7B is a front view of a boom and a protection member as in a third embodiment of the present invention.

MODES FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be discussed based upon the drawings. In FIG. 1, a hydraulic shovel 1 includes a crawler-type lower traveling body 2, an upper rotating body 3 rotatably supported upon the lower traveling body 2, a boom 4 mounted upon the upper rotating body 3, and so on. These structures may be conventionally arranged.
A cab 5 which secures a user space is arranged upon an upper portion of the upper rotating body 3 at one side (the left, for example) in a right and left direction of the boom 4. The cab 5 is mounted upon the upper rotating body 3 by the intermediary of a viscous mount not shown.
A rotating frame 6 is a mount base of the upper rotating body 3. A pair of right and left main frames 7R and 7L are provided to the rotating frame 6 so as to extend in a front-back direction of the rotating frame 6, as illustrated in FIG. 2. A base end portion of the boom 4 is supported at a front portion of the main frames 7R and 7L so as to be swingable in an upper and lower direction. A base end portion of right and left boom cylinders 9R and 9L is also supported at a front portion of the main frames 7R and 7L so as to be swingable in an upper and lower direction. The boom 4 swings by the right and left boom cylinders 9R and 9L.
A protection member 10, which is an example of a first embodiment of the present invention, is arranged upon an upper surface 4a of the boom 4, as shown in FIG. 3 and FIG. 4. The protection member 10 is formed such that a pair of plate members 11a and 11b, parallel to boom side surfaces 4b and 4c, are arranged to stand upon respective end portions of the upper surface 4a in its width direction and to face each other. Another plate member 11c connects with each upper portion of the pair of plate members 11a and 11b. The protection member 10 thus forms a gate shape. A platy reinforcing member 12 is installed into an inner surface of the gate shape so as to be orthogonal to the boom upper surface 4a and the boom side surface 4b. The platy reinforcing member 12 also has left, right, and upper end portions fixed respectively to inner surfaces of the plate members 11a, 11b, and 11c. The protection member 10, which comprises the plate members 11a, 11b and 11c, and the reinforcing member 12, is thus provided to be positioned in a side view so as to cover (overlap with) a front supporting column 5a or a roof portion 5b of the cab 5 within a swing range of the boom 4.
A notched portion 12a, which is an example of a pass-through portion of the present invention, is formed at a lower central portion of the reinforcing member 12. A space S is formed by the notched portion 12a and the boom upper surface 4a. A piping 13 which serves as an oil passage can be provided through the space S. Electrical wiring, etc., can also be provided through the space S.
The hydraulic shovel 1 is viewed from a side as illustrated in FIGS. 5A, 5B and 5C. The boom 4 and the protection member 10 overlap with a lower portion to a central portion of the front supporting column 5a of the cab 5 if the boom 4 is positioned at a most lowered position (see FIG. 5A). The boom 4 and the protection member 10 overlap with the central portion to an upper portion of the front supporting column 5a of the cab 5 if the boom 4 is positioned at a halfway position (see FIG. 5B). The boom 4 and the protection member 10 overlap with the roof portion 5b of the cab 5 if the boom 4 is positioned at a raised position (see FIG. 5C).
In the embodiment of the present invention arranged as discussed above, the protection member 10 is provided upon the upper surface 4a of the boom 4 such that the protection member 10 within the swing range of the boom 4 constantly overlaps with the front supporting column 5a or the roof portion 5b of the cab 5 in the side view. Whichever the boom 4 may be positioned at in the event that a machine body topples, the cab 5 that is tilted is thus pressed into contact with the boom 4 and the protection member 10. In particular, the front supporting column 5a of the cab 5 is pressed into contact with both the boom 4 and the protection member 10 so as to support the cab 5 even if the boom 4 is positioned at a lowered position. The cab 5 can thus be securely supported in any swing states of the boom 4 in the event of toppling.
It is the front supporting column 5a or the roof portion 5b of the cab 5a that corresponds to a region being pressed into contact with the boom 4 and the protection member 10 in the event of the machine body toppling. A front portion of the cab 5 is thus more protected and advantageous over a conventional structure in which a rear portion of the cab 5 is designed to be protected.
Although the protection member 10 is mounted upon the boom upper surface 4a, the piping 13 and the like, which are often placed upon the boom upper surface 4a, can be provided thereon through the notched portion 12a, the pass-through portion formed in the reinforcing member 12. This avoids a case in which a protection member is provided upon the main frames 7R and 7L, an apparatus is increased in size to impose a restriction on positioning of other members and devices, and maintenance workability is also decreased, for example. In addition, the reinforcing member 12 can provide its reinforcement to the inner surfaces of the plate members 11a, 11b, and 11c because the protection member 10 is arranged to bridge between the each end portion of the upper surface 4a of the boom 4. The protection member 10 as a whole can thus be simplified and downsized.
Furthermore, the piping 13 and the like, which are placed to penetrate through the notched portion 12a, are protected by the protection member 10. Therefore, even if the machine body topples, the piping 13 is prevented from being hit against by the cab 5, the oil passage is prevented from being fractured to effuse oil, and the electrical wiring and the like are also prevented from being disconnected.
The protection member 10 is arranged upon the boom upper surface 4a in the above-mentioned embodiment of the present invention, which is not restricted as such. A protection member 14 is illustrated in FIGS. 6A and 6B as in a second embodiment. The protection member 14 is arranged to stand toward an upper side of the boom 4 such that plate members 15a and 15b are supported by and parallel to the boom side surfaces 4b and 4c. In this case, a cab is supported by the plate members 15a and 15b together with the boom side surface 4b. Similar to the first embodiment, a plate member 15c bridges between the plate member 15a and the plate member 15b to form a gate shape as a whole. In the gate shape, a reinforcing member 16 is provided to include a notched portion 16a as a pass-through portion at a lower central surface portion. This is also similar to the first embodiment.
A protection member 17 is illustrated in FIGS. 7A and 7B as in a third embodiment. The protection member 17 includes a plate member 18 and a reinforcing member 19. The plate member 18 is arranged to stand upon a side of the side surface 4b of the upper surface 4a of the boom 4 so as to be inclined further in a direction of being away from a cab as the plate member 18 extends upward further. An upper end portion 19a of the reinforcing member 19 is connected with an upper end portion 18a of the plate member 18 such that the upper end portion 19a is substantially orthogonal to the plate member 18. A lower end portion 19b of the reinforcing member 19 is connected with the boom 4 at a side end portion of the boom side surface 4c on the boom upper surface 4a.
A pass-through portion 20 is formed in an internal space which is formed by the plate member 18 and the reinforcing member 19. Piping of oil passages and electrical wiring can be provided upon the boom upper surface 4a through the pass-through portion 20.
In the third embodiment as discussed above, the plate member 18 can be inclined in advance at a similar angle to angle of gradient of a cab side surface 5c based upon an assumption that a cab 5 is tilted. Accordingly, the plate member 18 can receive the tilted cab side surface 5c in a surface contact state, which allows for a further secures support of the cab 5. Moreover, the reinforcing member 19 can function as a beam because the reinforcing member 19 is substantially orthogonal to the plate member 18. An advanced cab supporting structure is thus provided.
Furthermore, the piping 13 and the like, which are provided upon the boom upper surface 4a through the pass-through portion 20, can be protected by the protection member 17 even if the machine body topples and the cab 5 hits against the boom 4 and the protection member 17. An oil passage of the piping 13 is thus prevented from being damaged to flow out oil. This is similar to the first and second embodiments.
Furthermore, because piping 13 and the like are simply arranged through the pass-through portion 20, the piping 13 and the like do not need to bypass the protection member 17. An efficient piping structure is thus provided.
The reinforcing member may be formed in a shape of a plate or a rod, and also may be single or plural.

INDUSTRIAL APPLICABILITY

The present invention is applicable for cab protection structures in construction machines such as hydraulic shovels to prevent cabs from being deformed and damaged in the event that machine bodies tip over, for example.

DESCRIPTION OF THE SYMBOLS

1: hydraulic shovel
4: boom
4a: boom upper surface
4b: boom side surface
5: cab
5c: cab side surface
5a: front supporting column
10: protection member

Claims

A cab protection structure in a construction machine, the construction machine comprising a boom mounted upon a machine body so as to swing up and down; and a cab provided at one side in a right and left direction of the boom, wherein a protection member is provided to protect the cab in the event that the machine body topples, characterized in that:
the protection member is provided upon the boom so as to project above an upper surface of the boom and to be positioned to overlap with a front supporting column region of the cab in a side view when the boom is at least in a lowered posture.
The cab protection structure in the construction machine according to claim 1, wherein the protection member is mounted to at least either one of the upper surface or a side surface of the boom.
The cab protection structure in the construction machine according to claim 1 or 2, wherein the protection member has at least a plate surface parallel to a side surface of the boom.
The cab protection structure in the construction machine according to any one of claims 1 to 3, wherein the protection member comprises:
a pair of plate members with a plate surface parallel to a side surface of the boom,

the plate members being separating and facing each other; and

a reinforcing member provided between the plate members.
The cab protection structure in the construction machine according to claim 4, wherein the protection member is formed to be a gate shape with an internal space formed by the pair of plate members and the reinforcing member.
The cab protection structure in the construction machine according to claim 1 or 2, wherein the protection member comprises:
a cab-side plate member with a surface inclined further in a direction of being away from the cab as the plate member extends upward further; and

a reinforcing member which is inclined so as to extend substantially perpendicularly from an upper end portion of the plate member to the boom.
The cab protection structure in the construction machine according to claim 5 or 6, wherein the protection member includes a pass-through portion in the internal space formed by the plate members and the reinforcing member so as to provide piping and wiring upon the upper surface of the boom through the pass-through portion.