JP5112149B2 - Column support structure and construction machine cab - Google Patents

Description

  The present invention relates to a column support structure and a cab for a construction machine having the column support structure, and more particularly to a column support structure for supporting a lower portion of a pair of column members and a cab for a construction machine having the column support structure.

2. Description of the Related Art In recent years, a structure that can protect a driver when a tumbler falls is being adopted as a cab structure in a construction machine, and EOPS (Excavator's Operation Protection Structure) performance has been regarded as important. For example, Patent Document 1 discloses a cab structure for a construction machine in which various pipe-shaped members are assembled in a bowl shape to form a frame structure. According to such a structure, the rigidity with respect to a deformation | transformation at the time of a construction machine falling down can be improved significantly compared with the cab structure comprised only by the combination of a sheet metal member.
JP 2005-329799 A (published December 2, 2005)

However, the conventional cab structure has the following problems.
As shown in FIG. 12 of Patent Document 1, the column member is supported by various support members. Examples of the support member include a base member that supports the lower end of the pillar member and a connecting member that extends to connect the base members together. These parts are fixed to each other by welding.

As described above, the number of parts and the number of welds are increased in the fulcrum portion of the column member, and the following problems occur.
1) The flatness of the bottom surface of the cab is improved due to distortion caused by welding. As a result, a distortion removing process is required.
2) Stress concentration increases at the fulcrum portion of the column member, and the strength decreases. In particular, it is important to tackle this problem because the fulcrum portions of the pair of pillar members on the front side are locations where stress is likely to concentrate.

  An object of the present invention is to provide a column support structure and a cab for a construction machine that can reduce problems in a fulcrum portion of a column member.

In the first invention according to the present invention, the column support structure supports a lower portion of a pair of left and right column members among a plurality of column members constituting a cab mounted on a turning frame of a construction machine, A pair of column support members are provided. The column support member includes an abutting portion that abuts on a lower side surface of the column member, and a connecting portion that is formed integrally with the abutting portion and extends from the abutting portion toward the other column member side of the pair of left and right column members. Have The ends of the connecting portions are connected by welding at a substantially center between the pair of left and right column members.

  Here, since the contact portion and the connecting portion of each column support member are integrally formed, the number of parts in the fulcrum portion of the column member is reduced as compared with the conventional case.

This Kodewa, connecting portions will be welded in substantially the center between the left and right pair of column members. Since the welding location is farthest from both the column members and the contact portion, the flatness of the cab bottom surface is improved.

Pillars supporting structure according to the second invention is a pillar support structure of the first inventions, the abutment portion includes a first portion which abuts the left-right direction side surfaces of the lower pair of right and left column members, left and right And a second portion that abuts against the front and rear side surfaces of the pair of column members. The surfaces of the first and second portions are mainly continuous via a curved surface.
Here, the reinforcing portion is in contact with the two side surfaces of the column member, thereby improving the strength of the lower portion of the column member.

This Kodewa, since the first portion and the second portion are continuous via a mainly curved surface can reduce the stress concentration with respect to each direction of the pillar member.

Pillars supporting structure according to the third invention is a pillar support structure according to the first or second inventions, the pair of right and left pillar members are a pair of right and left pillar members disposed in front of the cab.
Here, the column support members support a pair of left and right column members on the front side of the cab. The lower part of the pair of left and right column members on the front side of the cab and the part that supports it are parts where stress is likely to concentrate. On the other hand, in the column support structure of the present invention, the overall strength is improved by separating the weld from the column member. Therefore, it is significant to apply the column support structure of the present invention to a pair of left and right column members on the cab front side.

A cab for construction machinery according to a fourth invention includes the column support structure according to any one of the first to third inventions, and a plurality of column members.
Here, since the support member described above is used, the flatness of the entire cab surface is improved.

  According to the column support structure of the present invention, the contact portion and the connecting portion of each column support member are integrally formed, so that the number of parts in the fulcrum portion of the column member can be reduced as compared with the conventional case.

[Configuration of the entire device]
A hydraulic excavator equipped with a column support member and a cab in which the column support member according to an embodiment of the present invention is mounted will be described below with reference to FIGS.
Note that the terms “left and right”, “front and rear”, and “rear front” used in the following description indicate directions in the cab 10 (see FIG. 1 etc.) that are based on the direction that the operator faces when sitting on a chair. And

[Configuration of hydraulic excavator 1 as a whole]
As shown in FIG. 1, the hydraulic excavator 1 according to the present embodiment mainly includes a lower traveling body 2, a swivel base 3, a work implement 4, a counterweight 5, an engine 6, and a cab 10. ing.

The lower traveling body 2 has the crawler belt P wound around the left and right ends of the traveling direction rotated to move the excavator 1 forward and backward, and the swivel base 3 is mounted on the upper surface side in a swingable state. .
The swivel base 3 can swivel in any direction on the lower traveling body 2, and has a work machine 4, a counterweight 5, an engine 6, and a cab 10 mounted on the upper surface.

The work implement 4 is configured to include a boom, an arm attached to the tip of the boom, and a bucket attached to the tip of the arm. While moving the arm, bucket, and the like up and down by a hydraulic cylinder, Work at the site of civil engineering work where excavation of earth and sand and gravel.
The counterweight 5 is made of, for example, scrap iron or concrete in a box formed by assembling steel plates and hardened, and is provided at the rear part of the swivel base 3 to balance the vehicle body during mining or the like. ing.

The engine 6 is a drive source for driving the lower traveling body 2 and the work implement 4, and is disposed at a position adjacent to the counterweight 5.
The cab 10 is a driver's cab in which an operator of the excavator 1 gets on and off, and is disposed on the left front side on the swivel 3 so that the tip of the work machine 4 can be seen. . The cab structure of the cab 10 will be described in detail later.

[Structure of cab 10]
As shown in FIG. 2, the cab 10 is a box-shaped structure for an operator to get on and off, and includes five various column members 11 to 15.

The column members 11 to 15 are the left front column member 11, the right front column member 12, the left rear column member 13, the right rear column member 14, and the left center column member 15.
The left front pillar member 11 and the right front pillar member 12 are so-called A pillars, which are bent in the vicinity of the center portion, and a beam portion constituting a ceiling portion and a pillar portion standing from the floor surface in front of the cab 10. Including.

The left rear pillar member 13 and the right rear pillar member 14 are so-called C pillars, and are erected from the floor behind the cab 10 as substantially linear pillars.
The left central column member 15 is called a so-called B pillar, and is erected from the floor surface at a substantially central portion on the left side surface of the cab 10 or slightly behind it as a substantially linear column.

  The right front column member 12, the right rear column member 14, the left rear column member 13, the left center column member 15, and the left front column member 11 are connected by a floor frame 27. The left front column member 11 and the right front column member 12 are connected by a column support structure 31 (described later). Further, a floor cover (not shown) is mounted on the floor frame 27.

Furthermore, although not shown in FIG. 2, the left and right side panels, the ceiling panel, the rear panel, and the bottom panel are attached to the column members 11 to 15 of the cab 10.
Between the left front column member 11 and the left center column member 15 is an entrance / exit 21 of the cab 10, and a door 23 is provided therein as shown in FIG. The door 23 can be opened and closed with a hinge (not shown) as a rotation center. The cab 10 further has a seal structure (not shown) for preventing rainwater and dust from entering the cab 10 from the outside with the doorway 21 of the door 23 closed.

[Cub column support structure]
The left front column member 11 and the right front column member 12 are connected by a column support structure 31. Hereinafter, the column support structure 31 will be described.
As shown in FIG. 3, the column support structure 31 is an elongated member and includes a pair of column support members 33 and 33. The pair of column support members 33 are connected to each other by welding.

The pair of column support members 33, 33 have substantially the same shape. Therefore, hereinafter, only the configuration of the column support member 33 mounted on the left front column member 11 will be described in detail, and detailed description of the configuration of the column support member 33 mounted on the right front column member 12 will be omitted.
The column support member 33 is a part manufactured by forging or casting, for example. The column support member 33 mainly includes a base portion 33a, a connecting portion 33b, and a contact portion 33c. The base portion 33 a is a flat plate-like portion fixed on the end portion of the floor frame 27. The connecting portion 33b extends in one direction from the base portion 33a, and the end face of the connecting portion 33b is fixed to the end face of the other connecting portion 33b by welding.

Furthermore, the configuration of the column support member 33 will be described in detail with reference to FIGS.
The contact portion 33c is a wall-like member that is formed integrally with the base portion 33a and rises upward from the end portion of the base portion 33a. More specifically, the contact portion 33 c is formed at the left front end of the base portion, and includes a first contact portion 35 and a second contact portion 37. The first abutting portion 35 is a plate-like portion extending in the front-rear direction in plan view, and is in contact with the right side surface 11a of the left front pillar member 11 and connected by welding. The second contact portion 37 is a plate-like portion extending to the left side from the rear end of the first contact portion 35 and is in contact with the rear side surface 11b of the left front pillar member 11 and connected by welding. Here, the first contact portion 35 and the second contact portion 37 are in contact with the two surfaces 11a and 11b of the left front column member 11 as reinforcing portions, respectively, thereby improving the strength of the lower portion of the left front column member 11. is doing. Further, since the surfaces of the first contact portion 35 and the second contact portion 37 are smoothly continuous, stress concentration can be reduced in each direction of the left front column member 11.

  Here, since the contact portion 33c and the base portion 33a are integrally formed to constitute the column support member 33, the number of parts is reduced as compared with the conventional case. Moreover, since there are few parts, the welding location has decreased. Therefore, distortion due to welding is reduced and the flatness of the bottom surface of the cab 10 is improved. As a result, the work in the distortion removing process can be reduced.

  Further, the lower portion of the pair of left and right column members 11 and 12 on the front side of the cab 10 and the portion supporting the same are portions where stress is easily concentrated in the cab 10. On the other hand, the column support member 33 of the present invention is an integral member, so that the welded portion can be separated from the left front column member 11. Therefore, it is significant to apply the column support member 33 of the present invention to a pair of left and right column members on the cab front side. This is because the strength is improved by separating the welded portion from the column members 11 and 12.

The connecting portion 33b is mainly composed of a plate portion 39 and a step portion 41. The plate portion 39 is a flat portion extending from the base portion 33a. The step portion 41 descends from the upper surface of the first contact portion 35, extends along the plate portion 39, and protrudes upward from the plate portion 39.
The second contact portion 37 will be described in detail. The second contact portion 37 is a structure for supporting the lower portion of the left front pillar member 11 from the side together with the first contact portion 35. The second contact portion 37 has an upper surface 45, a rear side surface 47, and a front end surface 49.

  The upper surface 45 is a surface facing upward, and extends in the left-right direction. The rear side surface 47 is a curved surface that gently descends backward from the upper surface 45 and faces the left rear column member 13 side. The front end surface 49 is smoothly continuous from the rear side surface 47 and faces the left side (outside in the direction in which the column support member 33 extends). The second contact portion 37 further has a front side surface 48 and a lower side surface 50. The front side surface 48 is a substantially flat surface extending in the vertical direction, and abuts on the side surface 11b on the rear side of the left front column member 11. The lower side surface 50 abuts on the upper surface of the floor frame 27. The front end surface 49 is a surface facing the left side, and is defined by an upper surface 45, a rear side surface 47, and surfaces 48 and 50 on the opposite sides thereof. The surfaces such as the upper surface 45, the rear side surface 47, and the front end surface 49 are continuous with each other mainly through a curved surface. In other words, no corner is formed at the boundary between the surfaces. .

The welding locations of the column support member 33 to the left front column member 11 are only locations along the upper surface of the first contact portion 35 and the upper surface 45 of the second contact portion 37 of the contact portion 33c. Thus, the flatness of the bottom surface of the cab 10 is improved by minimizing the number of welds.
Further, the connecting portions 33b of the pair of column support members 33 are welded with their front end surfaces in contact with each other. Since the connecting portions 33b of the pair of column support members 33 are connected at the approximate center between the pair of left and right column members of the cab, the welding location is farthest away from both the column members 11, 12 and the contact portion 33c. ing. Therefore, distortion due to welding hardly affects the lower portions of the pair of column members 11, 12, the contact portion 33 c of the column support member 33, and the like. As a result, the flatness of the bottom surface of the cab 10 is further improved.

In this configuration, since the column support member 33 is a forged product or a cast product, it is easy to smoothly connect the plurality of surfaces 47 to 50 of the contact portion 33c.
As described above, by collecting members by forging, reduction of small articles and reduction of welded parts are realized. Furthermore, the stress concentration is eased by making the reinforcing part a smooth shape. Moreover, the stress concentration is eased with respect to the front-rear direction and the left-right direction of the fulcrum portion by forming the reinforcing portion so as to rise along the pair of column members. Furthermore, since the welded portion is limited to one place, the deterioration of flatness due to welding distortion can be minimized, and as a result, high accuracy can be realized.

[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.
In the above embodiment, the column support structure supports the pair of left and right column members on the front side of the cab. However, this may be used to support the pair of left and right column members on the rear side of the cab.

In the present embodiment, a hydraulic excavator has been described as an example, but the present invention can also be applied to a construction machine (wheel loader, bulldozer, etc.) other than the hydraulic excavator.
In the said embodiment, the detailed example of the contact part 33c of the column support member 33 was given and demonstrated. However, the present invention is not limited to this.

  Since the column support structure of the present invention has an effect that the number of parts in the fulcrum portion of the column member is smaller than that of the conventional structure, it can be widely applied to a cab for construction machines.

1 is a schematic side view of a hydraulic excavator in which a cab according to an embodiment of the present invention is employed. The perspective view of the cab in the state which removed the panel and the door. The perspective view of the support structure concerning one embodiment of the present invention. The top view of the support structure which concerns on one Embodiment of this invention. The top view of the supporting member which concerns on one Embodiment of this invention. The front view of the supporting member which concerns on one Embodiment of this invention. The perspective view of the lower end part of a 1st pillar member, and a part of support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 2 Undercarriage 3 Swing stand 4 Working machine 5 Counterweight 6 Engine 10 Cab 11 Left front pillar member 12 Right front pillar member 13 Left rear pillar member 14 Right rear pillar member 15 Left central pillar member 21 Entrance 23 Door 31 Column support Mechanism 33 Column support member 33a Base portion 33b Connecting portion 33c Contact portion 35 First contact portion 37 Second contact portion 39 Plate portion 41 Step portion 45 Upper surface 47 Rear side surface 48 Front side surface 49 Front end surface 50 Lower side surface

Claims (4)

A column support structure for supporting a lower portion of a pair of left and right column members among a plurality of column members constituting a cab mounted on a turning frame of a construction machine,
A contact portion that contacts the lower side surface of the column member; and a connection portion that is formed integrally with the contact portion and extends from the contact portion toward the other column member of the pair of column members. A column support structure comprising a pair of column support members , each of which is a pair of column support members , and ends of the connecting portions are connected by welding at substantially the center between the pair of left and right column members . The contact portion has a first portion in contact with the left-right direction side surface of the lower of the pair of right and left pillar members, the abutting second portion in the longitudinal direction side surfaces of the pair of right and left pillar members, the first The column support structure according to claim 1 , wherein the surfaces of the second portion and the second portion are continuous via a curved surface . The column support structure according to claim 1 or 2 , wherein the pair of left and right column members are a pair of left and right column members disposed on a front side of the cab. The column support structure according to any one of claims 1 to 3 ,
A cab for construction machinery equipped with.

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