JP4633028B2 - Carrier roller support structure of crawler type traveling device - Google Patents

Description

  The present invention relates to a carrier roller support structure for a crawler type traveling device employed in a traveling part of a vehicle such as a construction machine such as a backhoe.

  The crawler type traveling device employed in the backhoe has a traveling frame that supports the upper revolving body so as to be able to swivel around an axis in the vertical direction, and this traveling frame has a center in the center on which the upper revolving body is placed. The drive frame is mainly composed of a frame and side frames fixed to the left and right sides of the center frame, and is provided with drive wheels disposed at the rear of each of the left and right side frames and an idler disposed at the front. A plurality of wheels and the like disposed between the wheel and the idler are rotatably supported, and a crawler belt is wound around the drive wheels, idlers, wheels, etc. , And the drive wheels are driven to rotate by a hydraulic motor, and the crawler belt is circulated so as to move forward and backward (for example, Patent Documents 1 and 2).

In this type of crawler type traveling device, as shown in FIG. 16, a support arm 107 is projected upward in the middle of the side frame 101 having an inner wall 103, an outer wall 104, and an upper wall 105. A carrier roller 108 for pressing the middle part of the crawler belt upward is supported on the upper portion of the support arm 107 so as to be rotatable around the support shaft 109 in the left-right direction above the side frame 101. In the carrier roller support structure of the kind of crawler type traveling device, as shown in the figure, the lower end of the support arm 107 is welded to the upper surface of the upper wall 105 of the side frame 101, and the support arm 107 is located above the side frame 101. A discharge hole 110 was provided on the upper wall 105 of the side frame 101 so as to correspond to the lower side of the carrier roller 108 (for example, Patent Document 1).
JP 2005-313836 A JP 2003-48577 A

  However, in the conventional case, since the support arm 107 is attached by welding to the upper surface of the upper wall 105 of the side frame 101, it is sufficient to secure a welding width around the joint surface to the upper surface of the upper wall 105 of the support arm 107. A welded area with a large area is required, and mud or the like tends to accumulate in the welded part A between the discharge hole 110 and the support arm 77, and soil and sand dropped from the carrier roller 108 are in this welded part A. There is a problem that mud, sand or the like enters the dust seal portion of the carrier roller 108 and impairs the durability of the carrier roller 108. In order to solve this problem, simply expanding the discharge hole 110 around the support arm 107 of the side frame 101 reduces the strength of the side frame 101 to the running frame. There has been a demand for realizing a shape with good mud sweepability while ensuring the strength of the frame.

  In view of the above-mentioned problems, the present invention improves the mud sweepability while ensuring the strength of the side frame or the traveling frame so that dirt or the like does not collect between the discharge hole and the support arm. This is to improve durability.

The technical means of the present invention for solving this technical problem includes a side frame having an inner wall, an outer wall, and an upper wall on both sides of a traveling frame, and driving wheels and idlers before and after the side frame. A crawler belt is wound around these drive wheels and idlers, a support arm is projected upward in the middle of the side frame in the front-rear direction, and a middle part of the crawler belt is placed above the support arm. In a crawler type traveling device in which a carrier roller for pressing upward is supported above a side frame so as to be rotatable around a support shaft in the left-right direction.
The lower side of the support arm is fixed to the side frame, and the middle part in the vertical direction of the support arm is supported up and down on the upper wall of the side frame through the insertion hole of the upper wall. A discharge hole is provided corresponding to the above, and the insertion hole and the discharge hole of the upper wall are formed so as to be continuous from side to side.

  According to another technical means of the present invention, the lower part of the support arm is fixed to the inner wall of the side frame by welding or the like, and the middle part in the vertical direction of the support arm is vertically inserted into the insertion hole of the upper wall. A support shaft protrudes outward in the left-right direction at the top of the carrier, a carrier roller is supported on the support shaft so as to be rotatable about the support shaft, and a discharge hole in the upper wall is disposed outward in the left-right direction of the insertion hole, The discharge hole is formed to have a larger front-rear width than the insertion hole so that the discharge hole protrudes on both sides in the front-rear direction with respect to the insertion hole.

  According to the present invention, it is possible to prevent the accumulation of mud or the like between the discharge hole and the support arm in the upper wall of the side frame due to the mud or the like falling from the carrier roller, and it is closest to the dust seal portion of the carrier roller. Intrusion of mud and the like from the surface can be avoided, and the durability of the carrier roller can be improved. In addition, since the support arm can be raised from the inside of the side frame, it is possible to sufficiently secure the support arm and the side frame by welding or the like within the side frame, and to prevent a decrease in strength. It becomes possible. Therefore, it is possible to improve the durability of the carrier roller by improving the mud sweepability while ensuring the strength of the side frame or the traveling frame.

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, and the backhoe 1 mainly includes an upper turning body 2 (airframe) and a lower traveling device 3.
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. 1) is referred to as the left-right direction.
The swivel body 2 includes a swivel base 6 that is supported on the travel device 3 so as to be pivotable around a swivel axis X in the vertical direction, a work device (excavation device) 7 provided at the front of the swivel base 6, A driver's seat 8 provided on the base 6 and various devices mounted on the swivel base 6 such as an engine, a fuel tank, a hydraulic pump, a hydraulic oil tank, a control valve, a radiator, an oil cooler, a reserve tank, and a battery. Configured.

The swivel base 6 includes a swivel board 12 that is supported on the travel device 3 via a swivel bearing 11 so as to be pivotable about a swivel axis X, and a reinforcing member, various devices, and the like are mounted and fixed on the swivel board 12. And a rear part of the swivel base 6, and a rear part of the swivel base 6, and a rear part of the swivel base 6. Mainly composed of a counterweight 13.
A support bracket 16 projecting forward from the swivel base 6 is provided at the front portion of the swivel board 12, and a swing bracket 17 is supported on the support bracket 16 so as to be swingable left and right around the vertical axis.

A boom 18 that is swingably supported around the horizontal axis by the swing bracket 17, an arm 19 that is swingably supported around the horizontal axis at the distal end side of the boom 18, and a squeeze at the distal end side of the arm 19. The working device 7 is mainly composed of a bucket 20 attached so as to be capable of dumping. The boom 18, the arm 19, and the bucket 20 are a boom cylinder 21, an arm cylinder 22, and a bucket cylinder 23, each of which is a hydraulic cylinder. It can be operated by.
2 to 7, the traveling device 3 includes a traveling frame 27, on both the left and right sides of the traveling frame 27, drive wheels 30 disposed at the rear, idlers 31 (idling wheels) disposed at the front, these A plurality of rollers (lower rollers) 32 and carrier rollers (upper rollers) 33 disposed between the drive wheels 30 and the idler 31 are rotatably supported, and the drive wheels 30, the idlers 31, and the carriers are supported. A pair of left and right configured to wrap around an endless belt-like crawler belt 34 made of rubber or iron around the roller 33 and the roller 32, and to drive the driving wheel 30 with a hydraulic motor M or the like to circulate the crawler belt 34. A crawler traveling body 36 is provided. A dozer 35 is provided at the front of the traveling device 3.

As shown in FIGS. 2 to 6, the traveling frame 27 is roughly configured to include a center frame 37 and side frames 38 disposed on the left and right sides of the center frame 37.
The center frame 37 has an upper plate 39 and a bottom plate 40, and is erected between opposed inner surfaces of the upper plate 39 and the bottom plate 40, and upper and lower edges thereof are fixed to the upper plate 39 and the bottom plate 40. The left and right side vertical walls 42, the rear vertical wall and the front vertical wall 44 are provided. The upper plate 39, the bottom plate 40, and the vertical walls 42 and 44 are formed of an iron plate or a steel plate. That is, the main part of the center frame 37 constitutes a three-dimensional structure in which the upper plate 39 and the bottom plate 40 are connected by the vertical walls 42, 44 and the like.

The center portion of the center frame 37 is formed in a substantially rectangular shape in plan view. The center frame 37 rotatably supports the swivel body 3 via the swivel bearing 11 on the upper surface thereof, and a dozer 35 on the front portion thereof. I support it.
Specifically, a circular opening 46 penetrating in the vertical direction is formed in the upper plate 39 in the center portion of the center frame 37, and a bolt hole for attaching the swivel bearing 11 is formed around the opening 46. Many are formed.
In addition, a pair of left and right support brackets 53 are provided at the front of the center portion of the center frame 37 at the center in the left-right direction, and a pair of left and right support brackets 54 are provided on both left and right sides of the support bracket 53. Yes.

The rear end side of the dozer cylinder 55 that raises and lowers the dozer 35 is pivotally supported by the central support bracket 53 so as to be rotatable about the left and right axial centers, and the swing frame of the dozer 35 is supported by the left and right support brackets 54. The rear end sides of the left and right support arms 57 are pivotally supported so as to be rotatable about the axis in the left-right direction.
A pair of left and right front connecting legs 51 and a pair of left and right rear connecting legs 52 that protrude outward in the left-right direction and are connected to the left and right side frames 38 are provided on the front and rear sides of the left and right sides of the center frame 37. .

The center frame 37 is disposed at a position higher than the side frame 38, and the pair of front connecting legs 51 and the pair of left and right rear connecting legs 52 are made of a cast product, more specifically, made of cast steel. It is formed in an inclined shape that moves downward as it goes outward in the left-right direction.
The left and right side frames 38 include a main frame 59 which is disposed on the side of the center frame 37 and is long in the front-rear direction and is connected to the center frame 37 by the front connecting legs 51 and the rear connecting legs 52. A motor case 61 protrudes rearward from the rear end side of the main frame 59 via a connecting plate 60, and an idler holding portion 64 protrudes rearward from the front side of the main frame 59 via a connecting plate 63. Drive wheels 30 and an idler 31 are supported before and after the side frame 38, and a crawler belt 34 is wound around the drive wheels 30 and the idler 31.

The side frame 38 (main frame 59) includes an upper wall 72, an inner wall 73 extending downward from the inner side in the left-right direction of the upper wall 72, and an outer wall 74 extending downward from the outer end in the left-right direction of the upper wall 72. And a lower end side is opened.
The upper wall 72 is horizontal from the left and right inner ends to the left and right central portions, and descends outward so as to move downward from the left and right central portions to the left and right outer ends. It is inclined to. The left and right outer ends of the front connecting legs 51 are welded across the upper wall 72 and the inner wall 73 of the front portion of the main frame 59, and the left and right outer ends of the rear connecting legs 52 are the upper portions of the rear portion of the main frame 59. The wall 72 and the inner wall 73 are welded.

As shown in FIG. 15, the rolling wheel 32 is disposed at the lower part of the main frame 59 between the inner and outer walls 73 and 74 with a space in the front and rear direction, and is supported so as to be rotatable around a horizontal axis. Has been. The carrier roller 33 is supported on the upper wall 72 of the main frame 59 so as to be rotatable around a horizontal axis.
The motor case 61 is made of a cast product or a sheet metal, and is formed in a box shape having an opening on the inner side in the left-right direction. The hydraulic motor M is supported by the motor case 61 so as to protrude inward and outward through an attachment opening 68 shown in FIG. The motor case 61 is disposed inward in the left-right direction with respect to the main frame 59, and is fixed to the rear end of the main frame 59 by welding, a fastener, or other fixing means. The motor case 61 holds a hydraulic motor M that drives the drive wheels 30 so as to protrude outward in the left-right direction, and the drive wheels 30 are fixedly attached to the protruding portions. It is wound around the drive wheel 30, the idler 31, the wheel 32 and the carrier roller 33 so as to enclose.

The drive wheel 30 is rotationally driven by a hydraulic motor M so as to be able to rotate forward and backward. In FIG. 1, the crawler belt 34 circulates counterclockwise by the counterclockwise rotation of the drive wheel 30 and the backhoe 1 moves forward. The crawler belt 34 circulates in the clockwise direction by the clockwise rotation of the drive wheel 30 and the backhoe 1 moves backward.
As shown also in FIG. 15, a support arm 77 projects upward in the middle of the side frame 38 in the front-rear direction. The lower part of the support arm 77 is fixed to the inner surface of the inner wall 73 of the side frame 35 by welding or the like (the lower side of the support arm 77 is fixed to the side frame 38 in the side frame 38). Is inserted vertically through the upper wall 72 of the side frame 38 through the insertion hole 78 of the upper wall 72, and the carrier roller 33 is disposed above the side frame 38 around the support shaft 79 in the left-right direction above the side frame 38. It is supported rotatably. The carrier roller 33 presses the middle part of the crawler belt 34 upward. A support shaft 79 protrudes outward in the left-right direction at the upper portion of the support arm 77, and the carrier roller 33 is rotatably supported by the support shaft 79 around the support shaft 79, and penetrates in the left-right direction at the upper portion of the support arm 77. A mounting hole 81 is provided, and a slit 82 is provided upward from the mounting hole 81 so as to divide the upper part of the mounting hole 81 of the support arm 77 forward and backward, and a support shaft 79 is inserted into the mounting hole 81 to support it. A support shaft 79 protrudes outward in the left-right direction on the upper portion of the support arm 77 by tightening the upper portion of the attachment hole 81 of the arm 77 back and forth with a fastening tool.

  A discharge hole 84 is provided in the upper wall 72 of the side frame 38 so as to correspond to the lower side of the carrier roller 33. The insertion hole 78 is provided on the inner end side in the left-right direction of the upper wall, and the discharge hole 84 is provided at the center in the left-right direction of the upper wall 72 and on the outer side in the left-right direction of the insertion wall 78. 78 and the discharge hole 84 are formed to be continuous from side to side. The discharge hole 84 is disposed on the outer side in the left-right direction of the insertion hole 78, and the discharge hole 84 projects in the front-rear direction with respect to the insertion hole 78. Is greatly formed. A U-shaped reinforcing plate 85 is fixed to the upper surface of the opening edge of the insertion hole 78 and the discharge hole 84 of the upper wall 72 by welding or the like.

As shown in FIGS. 2 to 14, the idler holding portion 64 includes an inner wall 86, an outer wall 87, and an upper wall 88 that connects the upper ends of the inner and outer walls 86, 87, and the inner wall 86 of the idler holding portion 64. The outer wall 87 is made of sheet metal, and the upper wall 88 of the idler holding portion 64 is made of a cast product, more specifically, made of cast steel. The upper wall 88 is fixed to the upper ends of the inner wall 86 and the outer wall 87 by welding or the like.
The upper wall 88 of the idler holding portion 64 is inclined in a mountain shape so as to gradually increase from the left and right ends toward the center in the left and right direction, and a notch groove 90 is formed outwardly in the front and rear direction in the center portion of the upper wall 88 in the left and right direction. It is formed in a U shape in plan view so as to open. A U-shaped reinforcing protrusion 89 in a plan view that protrudes upward along the opening edge of the notch groove 90 is integrally provided on the upper wall 88.

The connecting plate 63 is fixed to the front end (one end) of the main frame 59. The inner wall 86 and the outer wall 87 of the idler holding portion 64 are fixed to the connecting plate 63 by welding or the like, and the upper wall 88 is welded or the like. The idler holding part 64 is protruded from the main frame 59 via the connecting plate 63 in the front-rear direction.
On the lower side of the inner wall 86 and the outer wall 87 of the idler holding portion 64, there are provided front and rear locking projections 91 protruding inward in the left-right direction, and both the left and right sides of the notch groove 90 of the upper wall 88 A pair of left and right engaging grooves 92 are formed between the engaging projection 91 and the front and rear. A yoke 94 is supported in the pair of engaging grooves 92 so as to be slidable back and forth. The idler 31 is attached to the yoke 94 so as to be rotatable around a support shaft 93 in the left-right direction, and the idler 31 is supported in a state of protruding from the notch groove 90 in the vertical direction and the front-rear direction outward.

As shown in FIG. 13, a tension device 95 is housed in the front part of each of the left and right main frames 59 in order to apply tension to the crawler belt 34 and adjust the tension.
According to the above embodiment, the upper wall 88 of the idler holding portion 64 is formed by casting (made of cast steel), and is fixed to the upper ends of the inner wall 86 and the outer wall 87 by welding or the like. Integrating with a cast product reduces distortion due to adhesion such as welding and secures high rigidity. In addition, the dimensional accuracy of the idler holding portion 64 can be accurately maintained, the sliding dimensions of the opening of the idler holding portion 64 can be easily managed, and the highly rigid idler holding portion 64 can be configured with the simplest possible member configuration. The configuration can be reduced, the number of parts can be reduced, and the manufacturing can be facilitated, leading to a shortening of the manufacturing process.

  Further, on the lower side of the inner side wall 86 and the outer side wall 87 of the idler holding part 64, a front-rear locking projection 91 protruding inward in the left-right direction is provided, and the left-right direction of the notch groove 90 in the upper wall 88 is provided. Since a pair of left and right engaging grooves 92 are formed between the both sides and the locking projection 91, the locking projections provided between the upper wall 88 and the side walls 86, 87 of the idler holding portion 64 are formed. The idler 31 can be slidably held back and forth through the yoke 94 with respect to the motor 91, and from this point as well, loads such as excavation reaction force and turning resistance during operation work as in the prior art. In order to secure sufficient rigidity in the portion, it is not necessary to adopt a complicated member configuration, and the manufacturing process is simplified as much as possible.

  Further, the lower side of the support arm 77 is fixed to the side frame 38, and the middle part in the vertical direction of the support arm 77 is inserted vertically through the upper wall 72 of the side frame 38 through the insertion hole 78 of the upper wall 72. 38 is provided with a discharge hole 84 corresponding to the lower side of the carrier roller 33, and the insertion hole 78 and the discharge hole 84 of the upper wall 72 are formed so as to be continuous from side to side. From the surface closest to the dust seal portion of the carrier roller 33, which can prevent the mud and the like from being generated between the discharge hole 84 and the support arm 77 in the upper wall 72 of the side frame 38. Intrusion of mud and the like can be avoided, and the durability of the carrier roller 33 can be improved. Further, since the support arm 77 can be raised from the inside of the side frame 38, the fixing of the support arm 77 and the side frame 38 by welding or the like can be sufficiently secured in the side frame 38, and the strength surface can be secured. It is also possible to prevent a decrease in the above. Accordingly, it is possible to improve the durability of the carrier roller 33 by improving the mud sweepability while ensuring the strength of the side frame 38 to the traveling frame 27.

  Further, the lower portion of the support arm 77 is fixed to the inner wall 73 of the side frame 35 by welding or the like, and a support shaft 79 protrudes outward in the left-right direction on the upper portion of the support arm 77, and the carrier roller 33 is supported on the support shaft 79. The discharge hole 84 of the upper wall 72 is supported so as to be rotatable around a shaft 79, and is disposed on the outer side in the left-right direction of the insertion hole 78. The discharge hole 84 protrudes from the insertion hole 78 on both sides in the front-rear direction. Since the discharge hole 84 is formed to have a larger front-rear width than the insertion hole 78, the discharge hole 84 can reliably prevent mud and the like from accumulating on the outer side of the upper arm 72 in the left-right direction of the support arm 77. Thus, the durability of the carrier roller 33 can be improved more reliably while securing the strength of the side frame 38 to the traveling frame 27.

In the embodiment, the lower portion of the support arm 77 is fixed to the inner surface of the inner wall 73 of the side frame 35 by welding or the like. Instead, the lower portion of the support arm 77 is connected to the upper wall of the side frame 35. 72 may be fixed to the front and back of the opening edge portion of the insertion hole 78 of the 72 by welding or a bolt and nut fastener, or the lower portion of the support arm 77 may be welded or fastened to the inner surface of the outer wall 74. You may make it adhere with tools.
In the above embodiment, the upper wall 88 of the idler holding part 64 is made of cast steel and is fixed to the upper ends of the inner wall 86 and the outer wall 87 by welding or the like. It may be formed by casting of pig iron other than cast steel, aluminum alloy or the like, and the upper wall 88 is fixed to the upper ends of the inner side wall 86 and the outer side wall 87 by fasteners of bolts and nuts other than welding. Also good.

  INDUSTRIAL APPLICABILITY The present invention can be used for a crawler type traveling device employed in a traveling unit of a vehicle such as a construction machine such as a backhoe.

It is a side view of the backhoe which shows one embodiment of this invention. It is a top view of the traveling frame. It is a side view of the traveling frame. It is a perspective view of the traveling frame. It is a top view of the state which removed the driving wheel, the idler, etc. of the traveling frame. It is a bottom view of the state which removed the driving wheel, the idler, etc. of the traveling frame. It is a front view of the state which removed the driving wheel, the idler, etc. of the traveling frame. It is a side view of the state which removed the driving wheel, the idler, etc. of the traveling frame. It is a perspective view of the state which removed the driving wheel, the idler, etc. of the traveling frame. It is a disassembled perspective view of the idler holding part. It is a perspective view of the front side part of the side frame. It is a perspective view of the side frame part. It is a plane sectional view of the front part of the side frame. It is a front view of the idler holding part. It is front sectional drawing of the carrier roller part. It is front sectional drawing of the carrier roller part which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Backhoe 2 Revolving body 27 Traveling frame 31 Idler 33 Carrier roller 34 Crawler belt 37 Center frame 38 Side frame 51 Front connection leg 52 Rear connection leg 59 Main frame 63 Connection plate 64 Idler holding part 72 Upper wall 73 Inner wall 74 Outer wall 77 Support arm 78 Insertion hole 79 Support shaft 84 Discharge hole 86 Inner side wall 87 Outer side wall 88 Upper wall 89 Reinforcing projection 90 Notch groove 91 Locking projection 92 Engagement groove 93 Support shaft 94 Yoke

Claims (2)

Side frames (38) having an inner wall (73), an outer wall (74), and an upper wall (72) are provided on both sides of the traveling frame (27). The wheel (30) and the idler (31) are supported, the crawler belt (34) is wound around the drive wheel (30) and the idler (31), and the side frame (38) is located in the middle in the front-rear direction. The support arm (77) protrudes upward, and the carrier roller (33) for pressing the middle part of the crawler belt (34) upward is provided above the support arm (77) above the side frame (38). In the carrier roller support structure of the crawler type traveling device supported rotatably around the left and right support shaft (79),
The lower side of the support arm (77) is fixed to the side frame (38), and the middle part of the support arm (77) in the vertical direction passes through the upper wall (72) of the side frame (38) through the insertion hole of the upper wall (72). The upper wall (72) of the side frame (38) is provided with a discharge hole (84) corresponding to the lower side of the carrier roller (33), and the upper wall (72) The carrier roller support structure for a crawler type traveling device, wherein the insertion hole (78) and the discharge hole (84) are formed to be continuous from side to side.   The lower part of the support arm (77) is fixed to the inner wall (73) of the side frame (35) by welding or the like, and the middle part in the vertical direction of the support arm (77) is vertically moved to the insertion hole (78) of the upper wall (72). The support shaft (79) is protruded outward in the left-right direction on the upper portion of the support arm (77), and the carrier roller (33) is rotatably supported around the support shaft (79) by the support shaft (79). The discharge hole (84) of the upper wall (72) is disposed outward in the left-right direction of the insertion hole (78), and the discharge hole (84) protrudes on both sides in the front-rear direction with respect to the insertion hole (78). In addition, the carrier roller support structure of the crawler type traveling device is characterized in that the discharge hole (84) has a larger front-rear width than the insertion hole (78).

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