JP2008240338A - Dozer device of working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hardly cause the breakage of a mounting bracket or a connecting member by enabling the alleviation of stress concentration on welded portions between the connecting member and the pair of mounting brackets. <P>SOLUTION: A notch is provided on the rear side of the connecting member which is composed of a pipe material; a bracket member, which comprises the pair of right and left mounting brackets and a connecting wall for connecting the pair of mounting brackets together, is provided; the bracket member is fixed to the connecting member by being fitted into the notch of the connecting member so that a back end surface of the connecting wall of the bracket member can be positioned ahead of a back end surface of the connecting member and so that the pair of mounting brackets can be protruded backward from the connecting member; and a front end of the dozer cylinder is connected between the pair of mounting brackets of the bracket member in such a manner as to be freely swingable on a horizontal supporting shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dozer device provided in a working machine such as a construction machine or a construction machine such as a backhoe.

In a dozer device for a work machine such as a backhoe, a blade is attached to a swing support that is supported on the machine body so as to be swingable up and down. The swing support includes a pair of left and right swing arms and a pair of swing arms. A connecting member that is made of a pipe material, and a dozer cylinder is provided between the connecting member and the fuselage side, and the swinging support body swings up and down by the expansion and contraction operation of the dozer cylinder. (For example, Patent Document 1 and Patent Document 2).
In this type of conventional work machine dozer device, as shown in FIG. 5, a pair of left and right mounting brackets 151 cut out in an arc shape are fixed to the rear side of the outer peripheral surface of the connecting member 152 by welding, The mounting bracket 151 protrudes rearward from the connecting member 152, and a connecting boss (cylinder clevis) 155 at the front end of the dozer cylinder 154 is inserted between the pair of left and right mounting brackets 151. The front end of the dozer cylinder 154 is swingably connected around the support shaft 157 via a connecting boss 155 (see, for example, Patent Documents). 1, Patent Document 2).
JP 2001-348904 A JP 2001-164597 A

  Therefore, conventionally, the dimension A from the axis S of the connecting boss 155 at the front end of the dozer cylinder 154 to the rear side of the outer peripheral surface of the connecting member 152 is set to the radius R of the connecting boss 155 and the outer peripheral surface of the connecting member 152. The length was such that a gap H in which the molten metal did not interfere with the connecting boss 155 was secured. For this reason, the dimension A from the axial center S of the connecting boss 155 of the dozer cylinder 154 to the rear side of the outer peripheral surface of the connecting member 152 is larger than the radius R of the connecting boss 155. There is a problem that the stress concentration on the welded portion between the member 152 and the pair of mounting brackets 151 is increased, and the mounting bracket 151 to the connecting member 152 are easily damaged.

  In view of the above problems, the present invention can alleviate the stress concentration on the welded portion between the connecting member and the pair of mounting brackets, so that the mounting bracket or the connecting member is not easily damaged.

The technical means of the present invention for solving this technical problem is that a blade is attached to a swing support that is supported on the machine body so as to be swingable up and down, and the swing support includes a pair of left and right swing arms and a pair. A connecting member for connecting the swinging arm of the body, the connecting member is made of a pipe material, a dozer cylinder is provided between the connecting member and the machine body side, and the swinging support body is swung up and down by the expansion and contraction operation of the dozer cylinder. In the work machine dozer device,
A rear end surface of the connecting wall of the bracket member is provided with a bracket member having a notch portion provided on the rear side of the connecting member made of pipe material, and having a pair of left and right mounting brackets and a connecting wall for connecting the pair of mounting brackets. Is positioned in front of the rear end surface of the connecting member and the pair of mounting brackets protrude rearward from the connecting member, and the bracket member is fitted into the notch portion of the connecting member and fixed to the connecting member. Between the mounting brackets, the front end of the dozer cylinder is pivotably connected around a support shaft in the left-right direction.

Further, according to another technical means of the present invention, a connecting boss having a horizontal axis is provided at a front end portion of the dozer cylinder, and the connecting boss is inserted between a pair of mounting brackets to move around the horizontal support shaft. The connecting boss is supported in the vicinity of the connecting wall between the pair of mounting brackets so that the front end of the connecting boss is positioned forward of the rear end surface of the connecting member.
Another technical means of the present invention is that the connecting boss is arranged so that the dimension from the axial center of the connecting boss provided at the front end of the dozer cylinder to the rear end of the connecting member is smaller than the radius of the connecting boss. It is in the point supported between a pair of mounting brackets.

  According to the present invention, since the rear end surface of the connecting wall of the bracket member is positioned in front of the rear end surface of the connecting member, the front end of the connecting boss on the front end side is positioned in front of the rear end surface of the connecting member. In addition, the connecting boss can be supported in the vicinity of the connecting wall between the pair of mounting brackets, and the dimension from the axial center of the connecting boss on the front end side to the rear end of the connecting member is smaller than the radius of the connecting boss. Therefore, the dimension from the axial center of the connecting boss at the front end of the dozer cylinder to the rear end face of the connecting member is smaller than the radius of the connecting boss. The stress concentration on the welded portion with the bracket can be alleviated, the mounting bracket or the connecting member is hardly damaged, and the connecting portion of the dozer cylinder to the connecting member can be made strong.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a backhoe exemplified as a (turning) work machine. The backhoe 1 is mainly composed of an upper turning body 2 and a lower traveling device 3, and a turntable 6 is arranged in a vertical direction. A small size in which the rear surface side of the swivel base 6 is formed in an arc shape (substantially arcuate) in plan view so that the rear surface side of the swivel base 6 does not protrude beyond the lateral width of the traveling device 3 even when turning around the swivel axis. This is called a rear small turning backhoe.
Note that the traveling direction of the backhoe 1 (the left-right direction in FIG. 1) is referred to as the front-rear direction, and the lateral direction orthogonal to the front-rear direction (the paper penetration direction in FIG.

Moreover, the machine body of the work machine 1 is comprised by the turntable 6, the traveling apparatus 3, etc. FIG.
The traveling device 3 rotatably supports an idler 8, a drive wheel 9, a track roller 10 and a carrier roller 11 on both left and right sides of the track frame 7, and has an endless belt-like elasticity in the form of a rubber crawler (or iron crawler). A crawler type traveling device is employed in which the crawler 4 is wound and the driving wheel 9 is driven by a hydraulic motor or the like.
The swivel body 2 includes a swivel base 6 that is supported on the travel device 3 so as to be swivel around a swivel axis in the vertical direction, a working device (excavation device) 12 provided at the front of the swivel base 6, and the swivel base 6. A driver's seat 13 provided above and various devices mounted on the swivel 6 such as an engine, a fuel tank, a hydraulic pump, a hydraulic oil tank, a radiator, and a battery are configured.

The swivel base 6 is provided with a counterweight 15 (protector) at the rear part that balances the weight of the working device 12 and the like provided at the front part of the swivel base 6 and constitutes the rear part of the swivel base 6.
A pair of upper and lower support brackets 16 is provided at the front portion of the swivel base 6 so as to protrude forward, and a support bracket 17 is supported by the support bracket 16 so as to be swingable left and right around the vertical axis.
A boom 18 supported by the support bracket 17 so as to be swingable about the horizontal axis, an arm 19 supported so as to be swingable about the horizontal axis on the tip side of the boom 18, and a tip side of the arm 19. The working device 12 is mainly composed of a bucket 20 attached so as to be able to perform a squeeze / dump operation. The boom 18, the arm 19, and the bucket 20 are a boom cylinder 21, an arm cylinder 22, and a bucket cylinder, which are hydraulic cylinders, respectively. 23 is operable.

A dozer device 5 is provided at the front of the traveling device 3.
As shown in FIGS. 2 to 4, the dozer device 5 is provided with a blade 30 at the front, and the blade 30 is supported on a track frame 7 of the traveling device 3 so as to be swingable up and down. It is attached to the front part of 31.
The swing support 31 includes a pair of left and right swing arms 33 and a connecting member 35 that connects the front and rear middle portions of the pair of swing arms 33 to the left and right, and between the front ends of the pair of swing arms 33. A blade 30 is attached to the blade. Cylindrical bosses 37 are provided at the rear ends of the pair of swing arms 33 corresponding to the left and right directions, and the rear ends of the pair of swing arms 33 are a pair of attachments that project forward from the track frame 7. Between the brackets, a boss portion 37 is supported so as to be swingable around a support shaft in the left-right direction.

The pair of left and right rocking arms 33 of the rocking support 31 is constituted by a thick plate that is a long plate material before and after the left and right direction is the plate thickness direction.
A dozer cylinder 61 is provided between the connecting member 35 and the machine body side, and the swing support 31 is swung up and down by the expansion and contraction of the dozer cylinder 61. The dozer cylinder 61 includes a cylinder main body 62 and a cylinder rod that moves out of and retracts from the cylinder main body 62. The dozer cylinder 61 positions the cylinder rod on the rear side of the cylinder main body 62, and It is arrange | positioned in the front-back direction between the connection member 35 and the body side.

The connecting member 35 is made of a pipe material. A notch 57 is provided on the rear side of the central portion of the connecting member 35 in the left-right direction. A bracket member 60 having a pair of left and right mounting brackets 58 and a connecting wall 59 that connects the pair of mounting brackets 58 is provided. The bracket member 60 is integrally formed of cast steel or configured by a sheet metal member. A pair of mounting brackets 58 are provided with mounting holes 64 corresponding to the left and right.
As shown in FIG. 3, the connecting wall 59 is formed in a U shape and fitted into the notch 57, and the upper end surface 59 a and the lower end surface 59 b of the connecting wall 59 are joined to the upper and lower notch end surfaces of the connecting member 35. In this state, the connecting wall 59 and the pair of mounting brackets 58 are welded to the connecting member 35, whereby the bracket member 60 is fitted into the notch 57 of the connecting member 35 and fixed to the connecting member 35. The rear end surface of the connecting wall 59 is located in front of the rear end surface of the connecting member 35, and a pair of mounting brackets 58 project rearward from the connecting member 35.

A front connection boss (cylinder clevis) 66 is provided on the bottom side of the cylinder body 62 that is the front end of the dozer cylinder 61, and a rear connection boss (cylinder clevis) is provided on the tip of the cylinder rod that is the rear end of the dozer cylinder 61. It has been. The front connection boss 66 and the rear connection boss are each formed in a cylindrical shape having an axis S in the left-right direction.
The rear end portion of the cylinder rod, which is the rear end portion of the dozer cylinder 61, is swung around the support shaft in the left-right direction between a pair of left and right support brackets protruding from the airframe side (track frame 7) via a rear connection boss. It is connected freely.

  The front connection boss 66 is inserted between the pair of mounting brackets 58, and the support shaft 68 is inserted into the pair of mounting brackets 58 and the front connection boss 66 in the left-right direction via the mounting holes 64 and the like. 66 is supported so as to be swingable around a support shaft 68 in the left-right direction, and the bottom side of the cylinder body 62, which is the front end portion of the dozer cylinder 61, is supported between the pair of mounting brackets 58 via the front connection boss 66. It is connected so that it can swing around. The front connection boss 66 is supported between the pair of mounting brackets 58 in the vicinity of the connection wall 59 so that the front end of the front connection boss 66 is positioned forward of the rear end surface of the connection member 35. The dimension A from the center S to the rear end of the connecting member 35 is set to be smaller than the radius R of the front connecting boss.

The blade 30 has a pair of left and right side plates 71, a front wall 72 provided between the pair of side plates 71, and a pair of side plates 71 that bulges backward from the lower end of the front wall 72 and is halfway in the vertical direction of the front wall 72. A rear wall 73 protruding toward the front portion and an upper reinforcing wall 74 provided at the rear of the upper end portion of the front wall 72, and a blade plate 76 is provided across the lower end of the front wall 72 and the front end of the rear wall 73. Yes.
A rear wall 73 of the blade 30 is fixed to the front ends of the pair of left and right swing arms 33 by welding or the like. A pair of reinforcing members 77 formed by bending an iron plate or the like into a U shape is fixed by welding or the like across the front outer surface of each swing arm 33 and the rear surface of the rear wall 73 of the blade 30.

  According to the above-described embodiment, the axis S of the front connection boss 66 that is the front swing fulcrum of the dozer cylinder 61 can be brought as close as possible to the rear end surface of the connection member 35, and the front connection boss of the dozer cylinder 61 can be obtained. The dimension A from the shaft center S of 66 to the rear end face of the connecting member 35 is smaller than the radius R of the front connecting boss 66. By reducing this dimension A, the dozer cylinder 61 and the mounting bracket 58 are conventionally used. A large moment does not act on the connecting member 35, stress concentration on the welded portion between the connecting member 35 and the pair of mounting brackets 58 can be alleviated, and the mounting bracket 58 or the connecting member 35 is not easily damaged and has a high strength. Can do.

Further, conventionally, as shown in FIG. 5, the mounting bracket 151 protrudes largely rearward from the outer peripheral surface of the connecting member 152, so that it becomes difficult to interrupt the welding torch when the mounting bracket 151 is welded to the connecting member 152. However, in the case of the above-described embodiment, the amount of protrusion from the outer peripheral surface of the connecting member 35 of the mounting bracket 58 is small, so that when the mounting bracket 58 is welded to the connecting member 35, a welding torch is used. Is easily interrupted, and the bracket member 60 is easily welded to the connecting member 35.
In addition, when the bracket member 60 having the pair of left and right mounting brackets 58 and the connecting wall 59 that connects the pair of mounting brackets 58 is integrally formed of a cast metal such as cast steel, an arc-shaped rear end surface portion of the mounting bracket 58 It is possible to weld the bracket member 60 to the connecting member 35 only by plane machining. From this point, it is possible to reduce the number of parts, shorten the welding process, and reduce stress. It becomes possible.

  In the above-described embodiment, the blade 30 of the dozer device 5 is fixed to the front part of the swing support 31 supported on the machine body so as to be swingable up and down by welding or the like, but the present invention is applied. The dozer device is not limited to such a device. For example, the angle blade 30 is supported by the swing support 31 supported on the machine body so as to swing up and down. The present invention can also be applied to an angle blade type dozer apparatus in which an angle cylinder is provided on the outer side of one swing arm 33 and the blade 30 swing support 31 can be swung in the left-right direction by this angle cylinder. it can.

  In the above-described embodiment, the dozer cylinder 61 is disposed in the front-rear direction between the connecting member 35 of the swing support 31 and the body side with the cylinder rod positioned on the rear side of the cylinder body 62. However, instead of this, the dozer cylinder 61 is arranged in the front-rear direction between the connecting member 35 of the swing support 31 and the airframe side with the cylinder rod positioned in front of the cylinder body 62. In this case, the front end portion of the cylinder rod, which is the front end portion of the dozer cylinder 61, is connected to the pair of mounting brackets 58 via a front connection boss or the like so as to be swingable about a left and right support shaft 68. do it.

1 is a side view of a work vehicle showing an embodiment of the present invention. It is a perspective view of the dozer device. It is side surface sectional drawing of the same dozer apparatus. It is a perspective view of the connection member and a bracket member. It is a side view which shows a prior art example.

Explanation of symbols

1 Backhoe (work machine)
DESCRIPTION OF SYMBOLS 5 Dozer device 30 Blade 31 Swing support body 33 Swing arm 35 Connecting member 57 Notch part 58 Mounting bracket 59 Connecting wall 60 Bracket member 61 Dozer cylinder 68 Support shaft

Claims (3)

A blade (30) is attached to a swing support (31) supported on the machine body so as to be swingable up and down. The swing support (31) includes a pair of left and right swing arms (33) and a pair of swings. A connecting member (35) for connecting the arm (33), the connecting member (35) is made of a pipe material, and a dozer cylinder (61) is provided between the connecting member (35) and the machine body side. In the dozer device of the working machine in which the swing support (31) is swung up and down by the expansion and contraction operation of the cylinder (61),
A notch (57) is provided on the rear side of the connecting member (35) made of pipe material, and a pair of left and right mounting brackets (58) and a connecting wall (59) for connecting the pair of mounting brackets (58) are provided. A bracket member (60) is provided, the rear end surface of the connecting wall (59) of the bracket member (60) is located in front of the rear end surface of the connecting member (35), and a pair of mounting brackets from the connecting member (35) The bracket member (60) is fitted into the notch (57) of the connecting member (35) and fixed to the connecting member (35) so that (58) protrudes rearward, and a pair of mounting brackets of the bracket member (60) (58) A dozer device for a working machine, characterized in that the front end of the dozer cylinder (61) is pivotably connected around a support shaft (68) in the left-right direction.   A connecting boss (66) having a left-right axis (S) is provided at the front end of the dozer cylinder (61), and the connecting boss (66) is inserted between the pair of mounting brackets (58). The connection boss (66) is supported by a pair of mounting brackets (66) so that the connection boss (68) is swingably supported around the support shaft (68) and the front end of the connection boss (68) is positioned forward of the rear end surface of the connection member (35). 58) The dozer device for a working machine according to claim 1, wherein the dozer device is supported close to the connecting wall (59).   The dimension (A) from the axis (S) of the connecting boss (66) provided at the front end of the dozer cylinder (61) to the rear end of the connecting member (35) is larger than the radius (R) of the connecting boss (66). The work machine dozer device according to claim 1 or 2, wherein the connecting boss (66) is supported between the pair of mounting brackets (58) so as to be smaller.

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