JP2014134077A - Working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve dischargeability of slurry in a front bracket of a working machine.SOLUTION: A working machine 1 is provided with an attachment 10 which is swingably supported about two shafts. The upper surface of a lower wall part 32 of a front bracket 30 formed of a casting and supporting a swing bracket 15 includes an inclined surface 47 extending downward to the rear side and side curved surface parts 53 having an arc-shaped cross section and extending along the lower edges of the inner surfaces of side wall parts 33. A rear wall part 34 has an opening 45, and at least a part of the lower edge of the opening 45 is located at the same height as that of a lowermost part 47a of the inclined surface 47 or located below the lowermost part 47a.

Description

  The present invention relates to a work machine in which an attachment can swing about two axes, a horizontal axis and a vertical axis, and particularly relates to a structure of a front bracket that supports the attachment.

  Generally, in such a work machine, a swing bracket is supported on a front bracket provided on an upper swing body so as to be swingable about a vertical axis, and the swing bracket is configured by a bucket, an arm, a boom, and the like. The attachment is supported so as to be swingable about the horizontal axis. Thereby, the attachment can perform not only the raising and lowering movement but also the swinging movement to the left and right.

  Such a structure of the swing bracket and the front bracket is disclosed in Patent Document 1, for example. Generally, the front bracket is often made of a can made by combining steel plates, but in Patent Document 1, it is made of precision cast steel.

  Although it does not relate to the front bracket in relation to the present invention, a construction machine that can reduce the accumulation of mud or the like that has entered the upper revolving structure is disclosed in Patent Document 2.

JP 2002-146834 A JP 2011-256627 A

  In this type of work machine, since the front bracket is exposed to the outside, there is a problem that muddy water enters the front bracket and accumulates therein.

  Since the mud contains a lot of solids, the mud accumulates and sticks when it accumulates. In order to smoothly discharge muddy water from the inside of the front bracket, including the soil mass formed in this way, it is necessary to provide a relatively large opening in the front bracket.

  However, if a large hole is made in the side surface or bottom surface of the front bracket, the strength and rigidity of the front bracket are lowered. If the thickness of the side surface or the bottom surface is increased in order to compensate for the reduced strength and rigidity, the weight and member cost of the front bracket increase.

  Therefore, an object of the present invention is to improve the front bracket of the work machine and improve the discharge performance while maintaining the strength and rigidity.

  In the present invention, by utilizing the fact that the front bracket is a cast product, the lower structure of the front bracket has been devised so that excellent drainage of muddy water and the like can be obtained while maintaining strength and rigidity.

  That is, the work machine according to the present invention is capable of swinging around two axes, a horizontal axis and a vertical axis, on a lower traveling body, a machine main body mounted on the lower traveling body, and a front side of the machine main body. And a supported attachment. The machine main body has a front bracket made of a cast product that supports a swing bracket that supports the attachment so as to be swingable about a horizontal axis, and swings about the vertical axis.

  The front bracket includes an upper wall portion, a lower wall portion, a pair of side wall portions and a rear wall portion, a fixed portion surrounded by upper, lower, left and right surfaces and a rear side surface, and the upper wall portion and the lower wall portion being forward. And a support portion that supports the swing bracket. The upper surface of the lower wall portion is a cross-section extending along the lower edge of the inner surface of each of the pair of side wall portions, the inclined surface descending rearward from the rear end portion of the support portion, and the inclined surface. And an arcuate side curved surface portion.

  The rear wall portion has an opening that opens in the front-rear direction, and at least a part of the lower edge of the opening is continuous with the lowermost portion of the inclined surface, and is at the same height as the lowermost portion. Is also located below.

  According to this working machine, since the upper wall portion and the lower wall portion constituting the support portion for supporting the swing bracket protrude forward, muddy water or the like enters the inside of the front bracket from between these. The muddy water that has entered is received on the upper surface of the lower wall portion of the front bracket, and on the upper surface, there are inclined surfaces that descend from the rear end of the support portion toward the rear, Since the side curved surface portion having the arcuate cross section is formed, the muddy water is smoothly guided to the lowermost portion behind the front bracket without accumulating in the corner portion.

  And since at least a part of the lower edge of the opening that opens in the rear wall portion is connected to the lowermost part of the inclined surface and is located at the same height or lower than this, muddy water is removed from the front bracket. It can be smoothly discharged to the rear of the front bracket through the opening without being held inside.

  In addition to integrating the front bracket by casting, the side curved surface part is provided, so that the fixed part of the box structure can be strengthened structurally, so that strength and rigidity can be maintained even if an opening is provided in the rear wall part .

  Specifically, the upper surface of the lower wall portion further includes a rear curved surface portion having an arcuate cross section that extends along the lower edge of the inner surface of the rear wall portion and continues to the inclined surface, A spherical thick portion may be formed at each corner below the inner surface of the rear wall portion where the curved surface portion and the rear curved surface portion intersect.

  If it does so, the discharge property of a muddy water will improve further by a thick part and a back curved surface part, and a rear wall part will also be strengthened structurally. Therefore, even if the opening is enlarged, the strength and rigidity can be maintained, so that the discharge performance can be further improved.

  More specifically, in the thick portion, it is preferable that the curvature radius on the rear curved surface portion side is larger than the curvature radius on the side curved surface portion side.

  By doing so, the rear wall portion can be further structurally strengthened, so that a larger opening can be formed. Accordingly, the muddy water discharge performance can be further improved.

  For example, a bundle of linear members extending from the attachment may be routed through the opening.

  Then, since a bundle of linear members (hydraulic piping, electrical wiring, etc.) can be routed without protruding outside the machine, the aesthetics can be improved and damage to the hydraulic piping can be prevented.

  According to the working machine to which the present invention is applied, since the front bracket is excellent not only in strength and rigidity but also in dischargeability, durability and aesthetics can be improved.

It is a schematic side view which shows the working machine of this embodiment. It is a schematic perspective view which shows the working machine of this embodiment. It is a schematic perspective view which shows a base. It is a perspective view which shows the joining structure of a front bracket. It is a disassembled perspective view which shows the joining structure of a front bracket. It is a schematic perspective view which shows the lower part of a front bracket. It is a schematic plan view seen in the cross section by the arrow line VV in FIG. It is a schematic sectional drawing in the arrow line WW in FIG. It is a schematic sectional drawing in the arrow line XX in FIG. It is a schematic sectional drawing in the arrow line YY in FIG. It is a schematic perspective view which shows the modification of a front bracket.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

  1 and 2 show a hydraulic excavator (work machine) 1 to which the present invention is applied. This hydraulic excavator 1 is a small model of a small rear turning type, and is composed of a crawler type lower traveling body 2 and an upper turning body (machine main body) 3 that is rotatably mounted thereon.

  A side machine room 4 containing a fuel tank, a hydraulic oil tank, and the like is disposed on the right side of the upper swing body 3, and a rear machine room 5 containing an engine and the like is disposed on the rear side of the upper swing body 3. ing. An operation space 6 including an operation seat, an operation lever, and the like is disposed on the left side of the upper swing body 3, and a hood 7 is installed on the upper side of the upper swing body 3 so as to cover the operation space 6.

  As shown in FIG. 3 and the like, unless otherwise specified, directions such as up, down, left, and right used in the description are based on the upper swing body 3.

  An attachment 10 is supported on the front side of the upper swing body 3 so as to be swingable about two axes of a horizontal axis HJ and a vertical axis VJ. The attachment 10 includes a bucket 11, an arm 12, a boom 13, hydraulic cylinders 14a to 14d, and the like.

  Specifically, the bucket 11 is supported at the tip of the arm 12 and swings about the first horizontal axis HJ1 extending in the lateral direction in accordance with the expansion and contraction of the bucket cylinder 14a that is hydraulically controlled. The arm 12 is supported at the base end of the boom 13 at the base end thereof, and swings about a second horizontal axis HJ2 extending in parallel with the first horizontal axis HJ1 according to the expansion and contraction of the arm cylinder 14b that is hydraulically controlled. Move.

  The base end portion of the boom 13 is supported by the swing bracket 15 and swings around the third horizontal axis HJ3 extending in parallel with the first horizontal axis HJ1 and the like in accordance with the expansion and contraction of the boom cylinder 14c that is hydraulically controlled. To do. The swing bracket 15 is supported by the front bracket 30 of the upper swing body 3 and swings about the vertical axis VJ extending in the vertical direction in accordance with the expansion and contraction of the swing cylinder 14d that is hydraulically controlled, as shown in FIG. To do.

  In FIG. 1 and FIG. 2, the illustration of hydraulic hoses and cables arranged along the attachment 10 is omitted.

  Therefore, in this hydraulic excavator 1, by operating an operation lever or the like, the attachment 10 can be moved up and down and swingable in the left-right direction. In order to maintain the front-rear balance with respect to the operating attachment 10, a heavy weight counterweight 8 is installed at the rear of the upper swing body 3.

  And in order to support the attachment 10, the counterweight 8, etc. stably, the upper turning body 3 is equipped with the base 20 excellent in intensity | strength and rigidity. The base 20 includes a lower frame 21, a pair of vertical plates 22, 22, a front bracket 30 and the like. FIG. 3 shows the base 20 in a simplified manner.

  The lower frame 21 is formed of a thick steel plate and a frame or the like assembled around the steel plate. The lower frame 21 is supported by the lower traveling body 2 via a swing bearing 23 so as to be swingable. A round hole 21 a for a swivel joint is formed in the central portion of the lower frame 21. The round hole 21 a is opened to the lower side of the lower traveling body 2 through the center portion of the slewing bearing 23.

  The pair of vertical plates 22 and 22 are disposed at the central portion in the left-right direction of the lower frame 21 and mainly reinforce the strength and rigidity of the base 20 in the front-rear direction. Each of these vertical plates 22 and 22 is made of a strip-shaped thick steel plate, is erected on the upper surface of the lower frame 21, and extends in the front-rear direction while facing away from each other in the left-right direction. In the hydraulic excavator 1, the vertical plates 22 and 22 are arranged in a V shape so as to gradually separate toward the rear side.

  Although not shown, a plurality of horizontal beams extending in the left-right direction are installed on the lower frame 21. The base 20 is structurally strengthened in the lateral strength and rigidity by these horizontal beams and the vertical plate 22.

  The counterweight 8 is placed on the lower frame 21 so as to straddle the rear portions of the vertical plates 22 and 22 so as to receive the load of the counterweight 8 at the rear portions of the vertical plates 22 and 22. Correspondingly, a front bracket 30 that receives the load of the operating attachment 10 is attached to the front portions of the vertical plates 22 and 22.

(Front bracket)
Specifically, as shown in detail in FIGS. 4 and 5, the front bracket 30 is sandwiched between the front end portions of the two vertical plates 22, 22 and is attached to the lower frame 21 and the two vertical plates 22, 22. It is fixed by welding.

  The front bracket 30 is a cast product and includes an upper wall portion 31, a lower wall portion 32, a pair of side wall portions 33, 33, a rear wall portion 34, and the like that are integrally formed. Each of the upper wall portion 31 and the lower wall portion 32 is a wall-shaped portion having a substantially triangular shape in a plan view with the front side narrowed, and faces away from each other in the vertical direction. Each side wall part 33 is a wall-like part that continues to the side edges of the upper wall part 31 and the lower wall part 32 that face each other in the vertical direction, and is opposed to the left and right sides.

  The side wall portion 33 is provided only in the rear portion of the upper wall portion 31 and the lower wall portion 32, and the front end portion of the upper wall portion 31 and the front end portion of the lower wall portion 32 are forward of the side wall portions 33, 33. Protruding. Thereby, on the front side of the front bracket 30, a support portion 38 formed of a pair of flange walls 31 a and 32 a facing vertically is formed.

  Each flange wall 31a, 32a has a substantially triangular shape in plan view, and a cylindrical boss portion 39 penetrating in the vertical direction is formed at the front end portion thereof.

  As shown in FIG. 1, the front bracket 30 supports the swing bracket 15 by the support portion 38. Specifically, a shaft cylinder portion 15a extending in the vertical direction of the swing bracket 15 is inserted between the upper and lower boss portions 39, 39, and the swing bracket 15 is supported by the front bracket 30 by connecting them with a shaft. Has been.

  Since the support portion 38 is exposed to the outside, rain water, mud, soil, etc. (collectively referred to as muddy water) from the gap between the upper and lower flange walls 31a, 32a, as indicated by white arrows in FIG. Enters the inside of the front bracket 30. Therefore, in this hydraulic excavator, the structure of the front bracket 30 is devised so that the muddy water that has entered the front bracket 30 can be guided to the lower frame 2 and easily discharged from the round hole 21a or the like to the outside of the machine (this point). Will be discussed later).

  The rear wall portion 34 is a wall-shaped portion that is located on the rear side of the front bracket 30 and continues to the lower surface of the upper wall portion 31, the upper surface of the lower wall portion 32, and the inner surfaces of both side wall portions 33 and 33. The rear wall portion 34 is substantially orthogonal to each of the upper wall portion 31, the lower wall portion 32, and both side wall portions 33, 33, and faces the front-rear direction.

  Each of the upper wall portion 31, the lower wall portion 32, the pair of side wall portions 33, 33 and the rear wall portion 34 forms a box structure in which the front bracket 30 is surrounded by the upper, lower, left, and right and rear surfaces. (This portion is also referred to as a fixing portion 35). Due to the fixing portion 35, the strength and rigidity of the rear portion of the front bracket 30 are structurally strengthened, and the front bracket 30 and the vertical plate 22 are firmly welded.

  The rear wall 34 is formed with a large oblong opening 45 penetrating in the front-rear direction.

  As shown in FIG. 4, a bundle 46 of hydraulic piping and electric wiring (linear members) extending from the attachment 10 is routed inside the upper swing body 3 through the opening 45. By arranging the bundles 46 of these hydraulic pipes through the opening 45, the bundles 46 of the hydraulic pipes can be arranged without protruding outside the machine, so that the aesthetics are improved and the hydraulic pipes are prevented from being damaged. Can be planned.

  That is, the opening 45 has a function as a guide hole that efficiently guides a bundle 46 such as a hydraulic pipe to the inside of the upper swing body 3. In addition, the opening 45 also has a function as a muddy water outlet for smoothly discharging muddy water that has entered the front bracket 30.

  Specifically, the structure of the upper surface of the lower wall portion 32 is used so that the muddy water that has entered can be smoothly discharged while maintaining high strength and rigidity by utilizing the fact that the front bracket 30 is an integral body by casting. Has been devised.

  6 to 10 show the lower part of the front bracket 30 in detail. In FIG. 7, changes in the curved surface of the upper surface of the lower wall portion 32 are simplified using contour lines (two-dot chain lines).

  As shown in FIG. 8, the upper surface of the lower wall portion 32 is an inclined surface 47 that descends rearward. Specifically, an intermediate portion in the left-right direction of the upper surface is an inclined surface 47 extending in the front-rear direction, and the inclined surface 47 is rearward from the edge of the boss portion 39 provided at the front end portion of the lower wall portion 32. Inclined gently down to the rear end of the lower wall portion 32.

  Therefore, on the upper surface of the lower wall portion 32, the edge at the rear end is the lowest (lowermost portion 47a). By connecting the lowermost portion 47a to the lower edge of the opening 45, a wide outflow region 48 located at the same height as or lower than the lowermost portion 47a is formed in the middle portion of the lower edge of the opening 45. Is formed.

  Moreover, the left and right sides and the rear side of the inclined surface 47 are formed in an R shape.

  Specifically, a side curved surface portion 53 extending along these edges is formed at a side corner constituted by the lower edge of the inner surface of each side wall portion 33 and the left and right edges of the upper surface of the lower wall portion 32. Is formed. As shown in FIG. 9, the side curved surface portion 53 has an arc-shaped cross section in contact with the inner surface of the side wall portion 33 and the upper surface of the lower wall portion 32.

  A rear curved surface portion 54 extending along these edges is formed at the rear corner portion constituted by the lower edge of the inner surface of the rear wall portion 34 and the rear edge of the upper surface of the lower wall portion 32. . The rear curved surface portion 54 also has an arcuate cross section that contacts the inner surface of the rear wall portion 34 and the upper surface of the lower wall portion 32, as shown in FIG.

  A spherical thick portion 55 is formed at each corner below the inner surface of the rear wall portion 34 where the side curved surface portion 53 and the rear curved surface portion 54 intersect.

  Specifically, the left and right corners formed by the left and right rear ends of the upper surface of the lower wall portion 32, the left and right ends of the inner surface of the rear wall portion 34, and the rear ends of the inner surfaces of the side wall portions 33 are inside. As a result, the thick portion 55 is formed. The thick portion 55 has a spherical cross section in contact with each of these surfaces.

  In particular, in the thick portion 55, the curvature radius r2 on the rear curved surface portion 54 side is larger than the curvature radius r1 on the side curved surface portion 53 side.

  That is, the radius of curvature r2 near the corner of the rear curved surface portion 54 is larger than the radius of curvature r1 near the corner of the side curved surface portion 53. Thereby, in the thick part 55, the rear part swells inward rather than the front part, and forms the gentle curved surface.

  Thus, by devising the structure of the upper surface of the lower wall portion 32, the muddy water can be smoothly discharged to the lower frame 21 through the opening 45 even if muddy water enters the front bracket 30.

  First, the muddy water that has entered the interior of the front bracket 30 is guided to the lowermost portion 47 a by the inclined surface 47. Since the outflow region 48 having a forward slope and a wide width is formed at the lower edge of the opening 45 where the lowermost portion 47a is continuous, even a large soil mass can be discharged from the front bracket 30 through the opening 45 without any problem.

  Since the side curved surface portion 53 and the rear curved surface portion 54 are formed on the left and right sides and the rear side of the inclined surface 47, mud is difficult to adhere. Moreover, since the spherical thick portions 55 are provided at the corners on the lower side of the inner surface of the rear wall portion 34 where mud adheres most easily, mud adhesion can be effectively prevented. Therefore, mud accumulation can be effectively suppressed.

  Moreover, since the side curved surface portion 53, the rear curved surface portion 54, and the thick wall portion 55 are provided, the strength and rigidity of the fixing portion 35 can be structurally reinforced, so that the side wall portion 33, the rear wall portion 34, and the lower wall The thickness of the portion 32 can be made relatively thin, and the front bracket 30 as a whole can be reduced in weight and member cost.

  In particular, by making the curvature radius r2 of the rear curved surface portion 54 relatively large, the base portion of the rear wall portion 34 is further strengthened, and a large opening 45 is formed in the rear wall portion 34 while maintaining strength and rigidity. It is possible. In addition, since the curvature radius r2 of the rear curved surface portion 54 is relatively increased, it is possible to suppress mud sticking and improve muddy water discharge.

(Modifications, etc.)
In addition, the working machine according to the present invention is not limited to the above-described embodiment, and includes various other configurations.

  For example, as shown in FIG. 11, by providing a lateral rib 56 extending in the left-right direction at an intermediate portion in the vertical direction of the opening 45, the opening 45 is partitioned into an upper guide hole and a lower muddy water discharge port. May be. If it does so, mud dirt of bundle 46, such as hydraulic piping, can be reduced.

1 Excavator (work machine)
2 Lower traveling body 3 Upper turning body (machine body)
DESCRIPTION OF SYMBOLS 10 Attachment 15 Swing bracket 30 Front bracket 31 Upper wall part 32 Lower wall part 33 Side wall part 34 Rear wall part 35 Fixing part 38 Support part 39 Boss part 45 Opening 47 Inclined surface 47a Bottom part 53 Side curved surface part 54 Back curved surface part

Claims (4)

A lower traveling body,
A machine body mounted on the lower traveling body;
An attachment supported on the front side of the machine body so as to be swingable about two axes of a horizontal axis and a vertical axis;
A working machine with
The machine body has a front bracket made of a cast product that supports a swing bracket that swings around the horizontal axis so that the attachment can swing around the vertical axis,
The front bracket is
A fixed portion whose upper and lower left and right and rear surfaces are surrounded by an upper wall portion, a lower wall portion, a pair of side wall portions and a rear wall portion; and
The upper wall portion and the lower wall portion are configured to protrude forward, and a support portion that supports the swing bracket;
Have
The upper surface of the lower wall portion is
An inclined surface descending rearward from the rear end of the support part;
A side curved surface section having an arc-shaped cross section extending along the lower edge of the inner surface of each of the pair of side wall sections, connected to the inclined surface;
Have
The rear wall portion has an opening that opens in the front-rear direction;
A work machine in which at least a part of a lower edge of the opening is connected to a lowermost part of the inclined surface and is located at the same height as or lower than the lowermost part. The work machine according to claim 1,
The upper surface of the lower wall portion further includes a rear curved surface portion having an arcuate cross section extending along the lower edge of the inner surface of the rear wall portion, connected to the inclined surface,
A work machine in which a spherical thick portion is formed at each corner below the inner surface of the rear wall portion where the side curved surface portion and the rear curved surface portion intersect. The work machine according to claim 2,
The work machine in which the curvature radius on the rear curved surface portion side is larger than the curvature radius on the side curved surface portion side in the thick portion. In the work machine according to any one of claims 1 to 3,
A work machine in which a bundle of linear members extending from the attachment is routed through the opening.

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