JP2005273143A - Backhoe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problems: the breadth of a conventional minimum-swing-radius type backhoe with the same work capacity is made greater; and forward protrusion is made greater in a rear-small-turning-radius type backhoe. <P>SOLUTION: This backhoe has a working machine 10 wherein a revolving frame 4 is equipped with a boom 13, an arm 12, a bucket 11, etc. The revolving frame 4 is constituted in such an elliptical shape as to be longitudinally longer in a plan view. At a corner part on either of the right and left sides of the front of the revolving frame 4, a notch 44 and a mounting part 45 for a base part of the working machine 10 are formed, and a base part of a first boom 17 of the working machine 10 is arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a backhoe technology in which the width of a swivel base frame is made narrow so that it can enter a narrow work place, and the swivel radius is also small, and more particularly to the structure of the swivel base frame.

  Conventionally, in a swivel working vehicle such as a backhoe, a swivel base frame is generally disposed on a traveling device, and a swivel base bearing is disposed in a central portion of the swivel base frame so as to be rotatable. A work machine including a boom, an arm, a bucket, and the like is disposed at the front of the frame, and an engine, a counterweight, and the like are disposed at the rear of the swivel.

Depending on the shape of the swivel frame, the type can be divided into the standard type, the small rear swivel type, and the ultra small swivel type. ) If you work while turning, there is a risk that the rear of the aircraft will hit an obstacle. In the rear small turning type, the shape of the rear part of the swivel frame etc. is formed in an arc shape that is substantially equidistant from the turning center, and the length twice the turning radius of the rear end of the fuselage is within 120% of the vehicle width. It is composed. In this case, the front end of the airframe may protrude forward from the turning radius of the rear end (see, for example, Patent Document 1). The ultra-small turning type is constructed so that the outermost turning radius of the fuselage is the same as or shorter than the vehicle width. Therefore, the plane shape of the machine body frame is a nearly circular shape (see, for example, Patent Documents 2 and 3).
As described above, a technique is known in which the turning radius is made as small as possible as compared with the standard type so that entry into a narrow work place is facilitated and work can be performed efficiently even in a narrow work place.

JP-A-11-269926 Japanese Patent Application Laid-Open No. 11-343636 Japanese Patent Laid-Open No. 11-256617

However, in such a turning work vehicle, when working with a turning work vehicle that can pass through the same road width, if an ultra-small turning type turning work vehicle is used, work capacity (balance and excavation range) is smaller than other types. turn into. In other words, since the mounting base of the work machine (boom) is disposed within the turning radius of the outermost end of the machine body, the upper body (equipment on the turntable frame) is made smaller than the traveling part width in consideration of the weight balance. It is necessary to reduce work capacity (balance and excavation range). Conversely, if the work capacity is the same, it is necessary to widen the vehicle width.

In addition, in the rear small turning type turning work vehicle, since the mounting base of the work machine is arranged at the front part of the airframe (swivel base frame), the upper portion having the necessary work ability when compared with the same vehicle width. The body can be larger than an ultra-small turning work vehicle. Conversely, when compared with the same work ability, the rear small turning type turning work vehicle can be made narrower than the ultra small turning type turning work vehicle.

Thus, when moving to a work place through a narrow road, the rear small turning type turning work vehicle is superior to the ultra small turning type turning work vehicle. However, since the working machine projects forward in the small turning type turning work vehicle, the turning radius of the front end is large and the workability may be reduced.
Therefore, the present invention is to provide a turning work vehicle having a small turning radius at the front part of the airframe while having the same work efficiency as that of the rear small turning type.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
That is, in claim 1, the backhoe includes a working machine 10 having a boom 13, an arm 12, a bucket 11, and the like on the swivel frame 4, and the oblong shape of the swivel frame 4 is long in the front-rear direction in plan view. It is configured.

  In Claim 2, it is a backhoe which has the working machine 10 provided with the boom 13, the arm 12, the bucket 11, etc. in the swivel frame 4, Comprising: The swivel frame 4 and the rear part 4b shape from the swivel center 40 in planar view. A circular arc having a radius R equal to or longer than the distance W to the side end, the left and right side surfaces are front and rear vertical surfaces having the same width or less as the crawler belt 64, and the front portion 4c is equal to or equal to the circle of the rear end turning locus 41 It is inside the circle and has an arcuate shape that bulges forward from a line 42 in the left-right direction connecting the intersection of the circle on the rear end turning locus and the crawler front side end.

  According to a third aspect of the present invention, a notch 44 is provided continuously to the arcuate front portion 4c in the plan view at the left and right side corners of the front portion of the swivel base frame 4.

  In Claim 4, the mounting part 45 of the base part of the working machine 10 is formed on the left and right corners of the front part of the swivel base frame 4, and the tip of the boom cylinder 23 faces the mounting part 45. Is.

  According to a fifth aspect of the present invention, a notch 44 is provided at the left and right corners of the front portion of the swivel base frame 4, and a mounting portion 45 of the base of the offset working machine 10 is disposed at the rear of the notch 44.

According to the sixth aspect of the present invention, the outer standing portion 45 b of the mounting portion 45 is also used as a side plate of the swivel base frame 4.
According to a seventh aspect of the present invention, a concave portion 45 c that opens upward is formed at the rear portion of the outer standing portion 45 b of the mounting portion 45.

As effects of the present invention, the following effects can be obtained.
By configuring as in the first aspect, the left and right width can be narrower than that of the conventional ultra-small turning type backhoe having the same work ability, and the vehicle can enter a narrow work place. In addition, compared with a small rear-turning backhoe, the forward length can be shortened and the driving space can be widened forward, so that the comfortability of the control section can be improved.

  By configuring as in claim 2, the left and right width can be narrower than that of a conventional ultra-small swivel type backhoe having the same work ability, and a narrow work place can be entered. In addition, compared with a small rear-turning backhoe, the forward length can be shortened and the driving space can be widened forward, so that the comfortability of the control section can be improved. And the front part of a turntable frame can be expanded without useless space to the circle of the rear end turning locus | trajectory 41. FIG.

  According to the third aspect of the present invention, the boom base mounting portion can be integrally formed at the notched portion without providing the protrusion and increasing the turning radius. Then, the boom base can be easily attached using the notch as a guide. In addition, since the notch is continuously provided on the curved surface, there is no large protrusion, the shape becomes gentle and the design is improved, and the boom base can be attached to the lowest possible position.

  By configuring as in the fourth aspect, the work implement can be arranged close to one side, and the space of the control section can be increased. And since a work machine is arrange | positioned toward the front, the space of walk-through can be ensured. Further, the boom cylinder tip can be protected by being surrounded by the mounting portion.

By configuring as in claim 5, the work within the lateral width can be performed by the offset working machine. In addition, the lateral width can be shortened compared to a conventional ultra-small turning type backhoe, and work in a narrow work place is possible. Further, when the boom is rotated forward and downward, it can be rotated downward without interfering with the swivel frame by the notch portion, and the boom rotation range can be expanded.
Further, by configuring as in claim 6, it is possible to bring the work implement (first boom) all the way to the right side of the swivel frame so that the control section can be widened. There is no need to newly provide a plate or the like for supporting the base. In addition, a shaft for pivotal support from the outside can be attached and detached, and maintenance and the like can be easily performed.
Further, according to the seventh aspect, maintenance of the boom cylinder and its piping from the recessed portion is facilitated, and assembly and the like can be facilitated.

Next, embodiments of the invention will be described.
1 is a left side view of the backhoe of the present invention, FIG. 2 is a rear view of the backhoe of the present invention, FIG. 3 is a plan view of the backhoe, FIG. 4 is a plan view of a swivel frame and a first boom, and FIG. FIG. 6 is a front view of the swivel frame, the boom cylinder, and the engine, FIG. 7 is a perspective view of the swivel frame, FIG. 8 is a perspective view of the first boom, the second boom, the offset cylinder, and the offset rod. FIG. 3 is a front view of a swivel frame, a boom cylinder, and a fuel tank.

  First, with reference to FIG. 1 to FIG. 3, an overall configuration of a turning work vehicle according to an embodiment of the present invention will be described as a backhoe. The backhoe 1 has an upper body arranged on a crawler type traveling device 2 so as to be able to turn left and right, and the upper body has a swivel bearing 3 disposed substantially at the center of the upper part of the swivel frame 4. The base frame 4 is supported by a bearing so as to be able to turn left and right. In the crawler type traveling device 2, a crawler belt 64 is wound around the outer periphery of the driving wheel 61, the driven wheel 62, and the rolling wheels 63 and 63. At the front and rear end portions (the front end portion in the embodiment shown in FIG. 1) of the crawler type traveling device 2, a soil discharge plate 5 is disposed so as to be rotatable up and down.

  A bonnet 6 that houses and covers the engine 24, the fuel tank 25, a battery, a hydraulic valve, a hydraulic oil tank, and the like is disposed above the swivel base frame 4, and a seat 7 is disposed on the bonnet 6. An operation column 8 is erected on the front end of the swivel frame 4 in front of the seat 7, and a step 33 is provided on the swivel frame 4 between the operation column 8 and the seat 7. And the lower end part of the working machine 10 is supported by the left-right front part (front part of the right side of the advancing direction in this example) of the swivel base frame 4 so that it can rotate back and forth. On the operation column 8, levers 55 </ b> L and 55 </ b> R for operating the work machine 10, the crawler type traveling device 2, etc., a foot pedal, and the like are disposed, and the control unit 9 is configured.

  Next, the configuration of the work machine 10 will be described with reference to FIGS. 1 and 2. The work machine 10 includes a bucket 11, an arm 12, a boom 13, a hydraulic cylinder group for operating these, a hydraulic piping system, and the like, and the bucket 11 serving as an attachment can be moved in the left-right direction with respect to the boom 13. It is an offset type work. The boom 13 is configured by connecting a first boom 17, a second boom 18, and a third boom 19 from the main unit side to the tip side.

  The bucket 11 which is a work attachment is pivotally supported by the tip end portion of the arm 12 at a rotation fulcrum 11a so as to be able to rotate back and forth. A bucket cylinder 16 is provided between a bottom side support point 16 a provided on the arm bracket 14 projecting above the base of the arm 12 and a rod side support point 16 b provided on the link mechanism 15 of the bucket 11. Is inserted. The bucket 11 is rotated by the expansion and contraction of the bucket cylinder 16.

  The base portion of the arm 12 is pivotally supported by the distal end portion of the third boom 19 at the pivot fulcrum 12a so as to be pivotable up and down. The arm cylinder 20 is interposed between a rod side support point 20 b provided on the base side of the arm bracket 14 and a bottom side support point 20 a provided on the base side of the third boom 19. The arm 12 is rotated as the arm cylinder 20 expands and contracts.

  The base portion of the third boom 19 is pivotally supported by the tip end portion of the second boom 18 at the pivot fulcrum 19a so as to be able to pivot left and right. Further, the root portion of the second boom 18 is pivotally supported by the distal end portion of the first boom 17 at the pivot fulcrum 18a so as to be able to pivot left and right. A bracket 37 for pivotally supporting a support shaft 22a at the upper end of an offset rod 22 to be described later is provided on the right side surface of the base portion side of the third boom 19 so as to project from the device side. A bracket 52 projects from the front end of the right side surface of the first boom 17, and a support shaft 22b that pivotally supports the lower end of the offset rod 22 provided on the bracket 52 is provided.

  An offset cylinder 21 is housed in the first boom 17, and a rod-side tip of the offset cylinder 21 is pivotally supported by a support shaft 21 a provided on a bracket 53 protruding to the right side from the base side of the second boom 18. A support shaft 21 b on the base side (bottom side) of the offset cylinder 21 is disposed in the lower portion of the first boom 17. The second boom 18 is rotated as the offset cylinder 21 expands and contracts. With this configuration, when the second boom 18 is rotated to the left and right, the offset rod 22 is also rotated to the left and right to move from the third boom 19 to the tip side (more specifically, the third boom). 19, the arm 12, and the bucket 11) move substantially in parallel to the left and right (offset movement) without inclining left and right in the rear view.

  The root portion of the first boom 17 is pivotally supported at the rotation fulcrum 17a at the front corner of the revolving frame 4 so as to be vertically rotatable. The lower end of the first boom 17 extends further downward than the rotation fulcrum 17a and is provided with a rod side support point 23b. The rod side support point 23b and a bottom side support point provided at the rear part of the swivel frame 4 ( The boom cylinder 23 is interposed between the support shaft 23a. When the boom cylinder 23 extends and contracts, the first boom 17 is rotated back and forth. At this time, the boom cylinder 23 is disposed in the swivel base frame 4 and is provided so that the boom cylinder 23 does not interfere with an obstacle during work.

Subsequently, each part will be described in detail.
The swivel frame 4 will be described with reference to FIGS.
The swivel base frame 4 is formed in a substantially oval shape that is long in the front-rear direction in plan view, and has a short left and right width so that it can easily enter a narrow work place. The swivel base frame 4 is integrally formed by casting, and can be easily manufactured to reduce costs. The work implement 10 is mounted on the right front corner in the direction of travel of the swivel base frame 4, the control unit 9 is disposed on the left front, the rear end is a counterweight, and the engine 24 is placed in the rear. A fuel tank 25 and a battery are arranged on the right side.

  The planar shape of the swivel frame 4 will be described in more detail. An opening is provided so as to attach the swivel bearing 3 to the front, rear, left, and right centers of the swivel frame 4, and the center is defined as a swivel center 40. The rear portion 4b of the swivel base frame 4 is made higher than the other portions, and the counterweight is made thicker and heavier, and its planar shape is formed in an arc shape with the swivel center 40 as the center. Has been. The distance from the turning center 40 to the rear portion 4b end of the turntable frame 4 is R, and the arc of the rear end portion is a radius R. That is, the turning track 41 at the rear end of the turntable frame 4 has a radius R. The left and right sides of the swivel frame 4 are side surfaces 4a and 4a that are raised from the bottom surface of the swivel frame 4 and are vertical surfaces in the front-rear direction. Is approximately the same as the vehicle width. The distance W from the side surface 4a to the turning center 40 is shorter than the radius R of the rear portion 4b. Therefore, the shape of the swivel frame 4 in plan view is such that the left and right sides of a circle with a radius R are cut off in the front-rear direction at the position of the left-right length W.

  The front portion 4 c of the swivel base frame 4 is formed in an arc shape so as to fit within a swivel trajectory 41 at the rear end of the swivel base frame 4. That is, the front portion 4c of the swivel base frame 4 is a convex portion that bulges forward from the left and right line 42 that connects the intersection of the turning trajectory 41 and the front outer ends of the left and right crawler belts of the crawler type traveling device 2, The bulged portion is arranged inside the radius R (the turning trajectory 41 at the rear end). By providing this forwardly bulging convex part, it becomes possible to expand the front part of the control part 9 forward than before, and in a small backhoe, the foot space is widened to increase the living space. It is possible to improve the performance. However, although the planar shape of the front portion 4c is formed in an arc shape in the present embodiment, it can be formed in a rectangular shape, a triangular shape, a trapezoid shape 4 or the like, and is not limited thereto. Although the front portion 4c is formed in an arc shape, as shown in FIG. 4, the center 43 of the arc is eccentric to the left side (reverse work machine side) from the left and right center and forward from the front and rear center. The work machine side is shaved so that the field of view on the work machine side is not narrowed.

  In addition, a notch 44 is provided at the front corner of the left and right sides (right side in the present embodiment) of the swivel base frame 4 continuously from the end of the curved portion of the front portion 4c, and a first boom is provided at the rear of the notch 44. 17 attachment portions 45 are formed. The notch 44 is formed by cutting the right front corner of the oval-shaped swivel frame 4 in an L shape in plan view to open the front, and when the first boom 17 is pivoted forward and downward, the swivel The interference with the frame 4 is prevented. That is, the work machine 10 can be rotated downward as much as possible. A mounting portion 45 for arranging the base portion of the work machine 10, that is, the lower portion of the first boom 17, is formed at the front left and right corners of the swivel frame 4, and is attached to the rear portion of the notch 44. A portion 45 is provided. In this way, the work implement 10 is arranged at the front part on the side as close to the side end as possible so that the space of the control unit 9 is increased, and the attachment base of the first boom 17 is attached to the lowest possible position. And the space which can get on and off from the right side is also obtained by arranging work implement 10 ahead. The mounting portion 45 is formed integrally with the swivel base frame 4 so that it can be easily molded at the time of manufacture to reduce the cost.

  The mounting portion 45 is raised from the bottom plate of the swivel frame 4 so as to rise up and protrude upwardly in the front-rear direction so that the upright portions 45a and 45b are substantially parallel to each other. . The upright portion 45a is formed at the side of the notch 44, the upright portion 45b is integrally formed at the front portion of the side surface 4a, and the outer upright portion 45b is also used as a side plate (side wall) of the swivel base frame 4. It is said. A fulcrum pin (fulcrum shaft) is inserted into a pin hole opened at the upper part of the upright portions 45a and 45b and a pin hole provided at a rotation fulcrum 17a at the lower part of the first boom 17, and is pivotally supported so as to be able to rotate back and forth. . That is, the fulcrum pin can be attached and detached from the outside to facilitate assembly and the like. Since the mounting portion 45 raised to the outside is integrally formed with the side surface 4a of the swivel base frame 4, the side plate and the mounting portion are combined, and a new one is separately provided to support the base portion of the first boom 17. A plate or the like is not attached to the first boom, and a mounting bracket is not assembled to the swivel frame 4 so that it can be obtained at low cost. Further, a recessed portion 45c that opens upward is formed in the rear side plate of the standing portion 45b so that maintenance and the like of the boom cylinder 23 and the like can be easily performed from the recessed portion 45c, and the assembly can be easily performed. And since the 1st boom 17 (work implement 10) can be supported on a side plate, the 1st boom 17 can be arrange | positioned near an outer end, and it is necessary to form the control part 9 in a narrow space in a small backhoe. However, as shown in this embodiment, the work implement 10 can be arranged on the opposite side from the control unit 9 and can be separated as much as possible, so that the space of the control unit 9 can be expanded compared to the conventional backhoe, It is possible to improve the habitability.

  The base portion of the first boom 17 can be inserted rearward from the front of the right corner of the swivel frame 4 while being guided by the upright portions 45a and 45b, and can be easily positioned on the mounting portion 45. Since the fulcrum pin can be assembled by inserting and removing from the outside in a pin hole opened in the outer surface 4a, assembly and maintenance can be facilitated. Further, the base part of the first boom 17 is attached to the attachment part 45, and the tip part of the boom cylinder 23 is attached to the attachment part 45, that is, the upright so that the tip part of the boom cylinder 23 is attached to the lower part of the first boom 17. It arrange | positions so that the lower part between part 45a * 45b may be faced. By doing so, the attachment portion of the first boom 17 and the boom cylinder 23 can be protected against obstacles from the side by the attachment portion 45.

Next, the arrangement configuration of the boom cylinder 23 will be described.
A boom cylinder 23 for rotating the first boom 17 is disposed substantially horizontally in the front-rear direction behind the mounting portion 45, that is, behind the base portion of the first boom 17. By arranging the boom cylinder 23 as low as possible in the lower part (bottom part) of the swivel base frame 4 as described above, the center of gravity can be lowered and stable compared to the case where the boom cylinder 23 is arranged on the front or rear surface of the conventional boom. The bucket capacity can be increased accordingly. In addition, as compared with the conventional configuration in which the boom cylinder is disposed on the front surface of the boom, when an attachment such as a bucket is pulled forward, damage to the cylinder can be prevented without interfering with the cylinder. In addition, when the boom cylinder is arranged on the rear side of the boom, the cylinder tube is arranged on the upper side, and the tip of the piston rod is arranged on the lower base side. Since the oil is fed and the operation in the reduction direction is performed, the working area is reduced and the thrust is reduced. However, in the present embodiment, the boom cylinder 23 is disposed in the horizontal direction, so there is no such a problem as described above. is there.

  The boom cylinder 23 is housed inside the swivel frame 4. That is, the swivel base frame 4 is formed in a box shape with the upper part opened, and the boom cylinder 23 is disposed inside the swivel base frame 4 below the upper end. The boom cylinder 23 is arranged along the side surface 4a on one side (right side) of the machine body, that is, arranged in a substantially horizontal direction in the front-rear direction in parallel with the side surface 4a serving as a side wall. By arranging in this way, the boom cylinder 23 and the pipe connected to the boom cylinder 23 are protected by being surrounded by the swivel frame 4, and can be prevented from being damaged without coming into contact with an obstacle or the like. . And the space of the lower right part of the turntable frame 4 can be used effectively.

  The base (bottom side) of the boom cylinder 23, that is, the rear end of the cylinder tube is configured to be supported in the rear portion of the swivel frame 4. That is, a recess 4d is formed in the lower part of the counterweight portion of the rear part 4b of the swivel base frame 4 so as to be recessed upward from the rear and lower surfaces. That is, a recess 4d that opens forward and downward in the swivel frame 4 is formed in a counterweight portion at the rear of the swivel frame 4, and a pin hole 4e is formed in the recess 4d in the left-right direction. A support portion on the bottom side (base portion) of the boom cylinder 23 is inserted into 4d, and the support portion is pivotally supported by a support shaft 23a such as a pin to serve as a bottom side support point. The support shaft 23a is detachable from the outer surface of the swivel base frame 4 so that assembly and maintenance can be easily performed.

  This support portion is located behind the turning center 40, and the recess 4d is formed by casting from the lower side so that a core is not required and can be configured at low cost. The boom cylinder 23 can be attached without reducing the weight of the weight portion. In addition, the rear end of the boom cylinder 23 can be arranged to the vicinity of the rear end of the swivel frame 4, and even with a small backhoe, the stroke of the boom cylinder 23 can be secured sufficiently, and the heavy cylinder By arranging the tube on the rear side, the front-rear balance can be improved. However, the boom cylinder 23 can be disposed along the outer side surface of the swivel base frame 4. In this case, a long recess in the front-rear direction recessed in the airframe inside or a L-shaped space in front view is formed, the boom cylinder 23 is disposed in the front-rear direction, and the open side is covered with a cover It can also be.

  Further, as shown in FIG. 6, a hydraulic pump 31 provided on the output shaft of the engine 24 is disposed above the rear part of the boom cylinder 23, that is, above the bottom side. With such a configuration, in a conventional rear small swivel type backhoe, the swing cylinder is disposed below the hydraulic pump. However, the swing cylinder swings in the left-right direction, whereas the boom cylinder 23 moves in the up-down direction. Swing. For this reason, it is possible to reduce the left-right clearance between the lower side surface of the engine 24 and the boom cylinder 23 and the left-right clearance between the boom cylinder 23 and the side inner wall, thereby further reducing the vehicle width. It became possible. The hydraulic pump 31 is disposed on an extension of the output shaft, a flywheel is disposed on the output shaft of the engine, and an oil pan or the like is disposed on the lower end, so that the height from the lower end of the engine 24 to the output shaft is high. Is necessary to some extent. Therefore, the space between the output shaft and the bottom surface of the swivel base has a space that can be sufficiently arranged even if the vertical swing range of the boom cylinder 23 is taken into account, and is more vertically movable than the left and right space. Therefore, the boom cylinder 23 can be easily arranged.

  Further, as shown in FIG. 9, a fuel tank 25 is disposed above the boom cylinder 23. The fuel tank 25 has an inverted L-shaped notch 25a formed on the lower side of the right or left in a front view in the bonnet 6, and a boom cylinder 23 is disposed in the notch 25a. In this embodiment, as shown in FIG. 9, the notch 25a is provided on the left side in the traveling direction, but it can also be provided on the right side. Thus, since the boom cylinder 23 swings up and down as described above, a dead space is generated in the swivel frame 4 on the left side or the right side of the boom cylinder 23. The lower portion of the fuel tank 25 is expanded in this space. Thus, the capacity can be increased by effectively using the dead space. However, the hydraulic oil tank can be arranged in the same configuration instead of the fuel tank 25.

The front end of the boom cylinder 23, that is, the tip of the piston rod is pivotally supported by the rod-side support point 23b at the lower end of the first boom 17, and the boom cylinder 23 is also extended to the stroke end. The front end of the cylinder 23 is located behind the front end of the swivel frame 4. That is, the front end 23 of the boom cylinder is disposed so as to be located inward from the maximum forward projecting portion. In this way, the boom cylinder 23 is positioned rearward, thereby improving the front / rear weight balance.
The pivot portion is located below the pivot point 17a of the first boom 17, and the entire boom cylinder 23 is also disposed below the pivot point 17a. In this way, when the boom cylinder 23 is expanded and contracted, the pivot support portion moves in the front-rear direction below the rotation fulcrum 17a so that the rotation angle of the work implement 10 can be secured.

  The boom cylinder 23 attached in this way is disposed below the step 33 in a side view, and does not get in the way when getting on and off from the right side, can be eliminated from the front view, and widens the view. be able to. When the boom cylinder 23 is expanded and contracted, the boom cylinder 23 is not configured to rotate with the boom (on the side of the boom), so the amount of bending of the pipe connected to the boom cylinder 23 is reduced, Bending fatigue is reduced, durability can be improved, and a space for preventing interference with the bending is not required, and the surrounding configuration can be easily configured. Further, in the plan view, the right end of the boom cylinder 23 is disposed on the outer side of the right end of the seat 7 and is disposed at a position that does not interfere with the engine 24 disposed below the seat 7.

Next, the configuration of the first boom 17 will be described.
The first boom 17 is configured in a cylindrical shape with the lower end closed and the upper end opened, with the first boom 17 positioned in the vertical direction. Projecting upward. That is, the opening 17h is provided on the upper surface of the first boom 17, and the storage recess 17b is formed downward from the opening 17h. The offset cylinder 21 is stored in the storage recess 17b. By adopting such a configuration, the working machine can be made compact, the periphery of the offset cylinder 21 is surrounded by the first boom 17, a cover is unnecessary, and interference with the attachment can be prevented, and the offset cylinder 21 itself In addition, the pipe connected to the offset cylinder 21 can be protected, and there is no risk of damage. The bucket 11 can be as close to the first boom 17 as possible, and the longitudinal length at the storage position can be shortened.

  In the side view, at least a part of the main body (cylinder tube) of the offset cylinder 21 is located in the projection surface of the first boom 17. In this embodiment, the entire cylinder tube is always located. With this configuration, the conventional offset cylinder is disposed on the side of the second boom located on the distal end side of the first boom 17, but in this embodiment, it is disposed below, that is, close to the fuselage. Therefore, the center of gravity of the work machine can be brought closer to the rotating base side of the work machine 10, and the weight balance of the work machine can be improved and work performance can be improved. If at least a part of the offset cylinder 21 is disposed within the projection plane of the first boom 17, the offset cylinder 21 is disposed on the right or left side of the first boom 17 and covered with a cover. It is also possible. Also in this case, the center of gravity of the work implement can be brought closer to the rotation base side.

  The first boom 17 is configured to be bent forward in a side view in the fully raised state shown in FIG. 1, and when the work implement 11 is lowered to the lowest end as shown by a dotted line, the front surface of the first boom 17 is The arm 12 and the bucket 11 can be rotated as much downward as possible while securing a gap so as not to interfere with the crawler belt 64 and the earth discharging plate 5.

  Further, in the rear view, the outer side surface (the right side surface in the traveling direction) of the first boom 17 is a vertical surface in the front-rear direction, and the side surface (left side surface) on the machine body center side in the longitudinal direction is curved to the right side. It is said. That is, in FIG. 4, a recess 17 c is formed on the side surface of the first boom 17 base side on the left and right center side of the body, and the recess 17 c is outside the right side (right side) of the center of the rotation fulcrum 18 a of the second boom 18. ). By configuring the recess 17c in this manner, the foot space in the control unit 9 is widened so that the first boom 17 does not interfere with the operation column 8 of the control unit 9 when the first boom 17 is rotated in the front-rear direction. .

  The upper end (front end) of the first boom 17 has a shape in which a mounting portion 17d protrudes obliquely toward the left side, that is, upward of the left and right center side of the body. A rotation fulcrum 18a is provided on the mounting portion 17d to pivotally support the base portion of the second boom 18. Thus, the center of the rotation fulcrum 18 a that connects the first boom 17 and the second boom 18 is arranged on the inner side of the machine body from the left and right center of the mounting base of the first boom 17. Further, the center of the rotation fulcrum 18 a is arranged so as to be located on the inner side of the body from the extension of the left and right center lines 46 of the boom cylinder 23. In this way, the second boom 18 is disposed above the pivot fulcrum 18a and is located as far as possible from the right end of the fuselage to the inside of the fuselage so that the amount of eccentricity of the offset work is as small as possible, while the first boom 17 is The space on the control unit 9 is widened so that the left side surface is located as far as possible on the right side (outside) so that it does not interfere with the operation column 9 when the work implement 10 is rotated back and forth, and the operator does not hit the work implement during work. I am doing so.

  A mounting portion 54 for pivotally supporting the support shaft 21b of the base portion (bottom fulcrum) of the offset cylinder 21 is formed at the inner bottom portion of the storage recess 17b formed in the first boom 17. The mounting portion 54 is positioned below the middle part of the first boom 17 and has openings 17e and 17f for maintenance and assembly on the outer surface, and the opening 17e is positioned on the side of the mounting portion 54. I am letting. The mounting portion 54 is erected from the inner surface of the storage recess 17b. As shown in FIG. 8, a pin hole 17g is opened on the front surface of the first boom 17 in front of the mounting portion 54, and the pin hole 17g. The base of the offset cylinder 21 is positioned between the mounting portion 54 and the pin hole of the mounting portion 54, the support shaft 21 b is inserted from the front outer side, and the base of the offset cylinder 21 is pivotally supported by the mounting portion 54 and the front surface. It is said. By comprising in this way, it becomes unnecessary to provide separately the plate etc. for pivotally supporting the offset cylinder 21 base part, and it can reduce a number of parts and can comprise at low cost. And since this 1st boom 17 is integrally formed with the casting, it can be comprised easily cheaply. In addition, as shown in FIG. 4, the bottom part of the accommodation recessed part 17b is located in the upper part of the said recessed part 17c, and the base part side of the 1st boom 17 is made thin so that the space of the recessed part 17c may become large. Further, the bottom of the housing recess 17b is made to coincide with the lower end of the opening 17e so that even if soil or water enters from the opening 17h, it is discharged from the opening 17e.

Next, the structure of the 2nd boom 18 is demonstrated using FIG.1, FIG.2, FIG.8. The second boom 18 and the third boom 19 are offset in the front-rear direction in a state where the work machine 10 is rotated to the highest position, that is, in a state where the boom cylinder 23 is extended to the stroke end. In the state where the bucket 11 is close to the first boom 17 (hereinafter, this state is referred to as “work machine standard position”).
The second boom 18 has a configuration in which both ends are formed in a “h” shape in a side view and the base side and the tip side are separated from each other, and the base side is inserted between the mounting portions 17d and 17d to the rotation fulcrum 18a. The second boom 18 is pivotally supported by the provided fulcrum shaft and is connected to the first boom 17 so as to be turnable in the left-right direction. The distal end side of the second boom 18 is pivotally supported on the base side of the third boom 19 by a fulcrum shaft provided on the rotation fulcrum 19a, and the third boom 19 is connected to the second boom 18 so as to be rotatable left and right. ing. The fulcrum shafts of the rotation fulcrums 18a and 19a are oriented in the front-rear direction and arranged in parallel vertically.

  At the work machine standard position, as shown in FIG. 1, the rear end of the connecting portion between the second boom 18 and the third boom 19 is the front end of the connecting portion (the rotation fulcrum 18 a) of the base portion of the second boom 18. From the line 47 extending vertically upward with respect to the rotation fulcrum axis. With this configuration, the third boom 19 can be disposed as far forward as possible, and the offset cylinder 21 is extended and the second boom 18 is tilted (offset) toward the control unit 9 side. The third boom 19 is located in front of the operator and does not interfere with the operator.

  As shown in FIG. 2, a bracket 53 protrudes obliquely outward and downward from the base side of the second boom 18, and the piston rod tip of the offset cylinder 21 is pivotally supported on the bracket 53 by a support shaft 21a. The bracket 52 projects from the first boom 17 above the support shaft 21a, and the lower end of the offset rod 22 is pivotally supported by the support shaft 22b. The upper end of the offset rod 22 is pivotally supported by a fulcrum shaft 22 a on a bracket 37 projecting obliquely outward and downward from the rear end of the third boom 19, and the offset rod 22 is disposed substantially parallel to the second boom 18.

  Thus, at the work machine standard position, the offset rod 22 is disposed above and in front of the offset cylinder 21, and the second boom 18 is disposed above the offset cylinder 21. Further, the offset rod 22 and the offset cylinder 21 are arranged on the right side which is the same side on the left and right with respect to the rotation fulcrum 18a connecting the first boom 17 and the second boom 18, and are arranged on the opposite side in the vertical direction. However, the offset rod 22 can be arranged on the opposite side to the offset cylinder 21. With this configuration, the offset cylinder 21 is disposed in the vicinity of the first boom 17, the offset rod 22 is disposed in the right side near the second boom 18, and the offset cylinder 21 is expanded and contracted to extend the second boom. Even when the front end of the third boom 19 is offset by swinging the left and right 18, the first boom 17 and the offset cylinder 21 are substantially parallel, and the second boom 18 and the offset rod 22 are also substantially parallel. Is maintained. Thus, the boom cylinder 23 and the offset cylinder 21 are arranged on the airframe side of the conventional backhoe, the center of gravity of the work machine 10 is also located on the airframe side, and work stability can be improved. The bucket capacity can also be increased. Further, the offset cylinder can be eliminated from the side portion of the second boom 18, the tip side of the work machine 10 can be simply configured, and the handling of piping and the like can be simplified.

  Then, at the working machine standard position, the base of the arm 12 is pivotally supported at the tip of the third boom 19 by a rotation fulcrum 12a, and the upper part of the third boom 19 is opened in the U-shaped rear view. The portion 19b is formed, the cylinder tube of the arm cylinder 20 is disposed in the bracket portion 19b, the rear portion of the arm cylinder 20 is pivotally supported by the bottom support point 20a, and the piston rod tip of the arm cylinder 20 is connected to the arm 12 The arm bracket 14 disposed at the upper portion of the rod is pivotally supported by the rod side support point 20b. In this way, the arm 12 can be rotated back and forth by expanding and contracting the arm cylinder 20.

  The base of the bucket 11 is pivotally supported at the tip of the arm 12 by a pivot fulcrum 11a, and the base side of the bucket cylinder 16 is pivotally supported by a bottom support point 16a on an arm bracket 14 formed at the top of the arm 12. The tip of the piston rod of the bucket cylinder 16 is pivotally supported with the links 15a and 15b by the rod-side support point 16b, the other end of the link 15a is pivotally supported at the tip of the arm 12, and the other end of the link 15b is the bucket. 11 is pivoted to the base side. By expanding and contracting the bucket cylinder 16 in such a configuration, the bucket 11 can be swung back and forth and swung and swung.

  In the state where the offset type work implement 10 configured as described above is positioned at the work implement standard position, as shown in FIG. 2, the outer end (right end) of the first boom 17 serving as the right end face of the work implement 10 is The swivel base frame 4 and the crawler type traveling device 2, that is, are arranged on substantially the same plane as the outer surface (right end surface) of the machine body. Further, the right end of the second boom 18 or the right end of the offset rod 22 is disposed so as to be located substantially on the same plane as the outer end face (right side face) of the machine body or on the inner side. With such an arrangement, the work machine 10 can be positioned within the vehicle width and can easily enter a narrow work place without the work machine 10 hitting a wall or the like. It can arrange | position near a right end and can enlarge the space of the control part 9. FIG.

  In the state in which the offset working machine 10 is positioned at the working machine standard position, the rear end of the working machine 10, in this embodiment, the rear end of the first boom 17, as shown in the side view of FIG. 7 or the front end of the bonnet 6 or the turning center 40, and behind the front end of the turntable frame 4 (airframe), that is, inside the rear end turning track 41. .

  With this configuration, when the work implement 10 is raised to the maximum and rotated backward, a space can be formed between the seat 7 and the work implement 10, and penetrates in the left-right direction on the step 33. A space is formed. That is, the walk-through passage can be configured in the left-right direction across the maximum width of the swivel frame 4 behind the work machine 10. Thus, it is possible to get on and off from both the left and right sides, and workability can be improved. Moreover, the space opened in the left-right direction on the step 33 can be formed, so that the operator space of the control unit 9 can be configured to be large. And since it does not contact an operator even if the work implement 10 is rotated backward, the canopy becomes unnecessary, and it is possible to lower the work implement 10 and enter the work place having an obstacle lower than the canopy. It becomes.

  Further, in a state where the offset type work machine 10 is located at the work machine standard position, as shown in the side view shown in FIG. 17 and the operation column 8 are arranged substantially parallel to each other so as to wrap in a side view. By configuring in this way, it becomes possible to secure a space for walk-through between the operation column 8 and the rear portion of the first boom 17 and the seat 7, and it is possible to get on and off from both the left and right sides, improving workability. As a result, the operator space in the control unit 9 can be increased.

  In addition, when the offset type work machine 10 is positioned at the work machine standard position, the upper ends of the operation levers 55L and 55R serving as the operation members arranged on the operation column 8 are as shown in the side view of FIG. It is configured to be substantially the same height as the upper end of one boom 17 or slightly lower. With such a configuration, even if the second boom 18 disposed on the upper portion of the first boom 17 is offset and rotated to the control unit 9 side, it does not hit the operator and does not hinder the operation. In this backhoe, the maneuvering unit 9 can be made as large as possible to facilitate maneuvering, and the work implement 10 can be configured compactly.

The left view of the backhoe of this invention. The rear view of the backhoe of this invention. The top view of a backhoe. The top view of a turntable frame and a 1st boom. The right view of a turntable frame and a 1st boom. The front view of a turntable frame, a boom cylinder, and an engine. The perspective view of a turntable frame. The perspective view of a 1st boom, a 2nd boom, an offset cylinder, and an offset rod. The front view of a turntable frame, a boom cylinder, and a fuel tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 Turntable frame 4b Rear part 4c Front part 10 Working machine 11 Bucket 12 Arm 13 Boom 17 First boom 40 Turning center 41 Rear end turning locus 42 Left and right direction line 44 Notch 45 Attachment part 64 Crawler belt

Claims (7)

  A backhoe having a working machine 10 provided with a boom 13, an arm 12, a bucket 11, and the like on a swivel base frame 4, wherein the swivel base frame 4 is configured in a substantially oval shape long in the front-rear direction in a plan view. Backhoe to do.   The backhoe includes a working machine 10 having a boom 13, an arm 12, a bucket 11, and the like on the swivel frame 4, and the swivel frame 4 has a rear Wb shape in a plan view, and a distance W from the swivel center 40 to the side end. The left and right side surfaces are front and rear vertical surfaces having the same width or less as the crawler belt 64, and the front portion 4c is equal to or inside the circle of the rear end turning locus 41. The backhoe is characterized in that it has an arcuate shape that bulges forward from a line 42 in the left-right direction connecting the intersection of the circle of the rear end turning locus and the front end of the crawler belt.   The backhoe according to claim 1 or 2, wherein a notch (44) is provided continuously to the front part (4c) having a circular arc shape in a plan view at the left and right side corners of the front part of the swivel base frame (4).   A mounting portion 45 of a base portion of a work machine 10 is formed on a front left and right corner of the swivel frame 4, and the tip of the boom cylinder 23 faces the mounting portion 45. Item 3. A backhoe according to item 1 or item 2.   The notch 44 is provided in the front left and right corners of the swivel base frame 4, and the mounting portion 45 of the base of the offset working machine 10 is disposed at the rear of the notch 44. 2. The backhoe according to 2.   6. The backhoe according to claim 4, wherein an outer standing portion 45 b of the mounting portion 45 is also used as a side plate of the swivel base frame 4. 6. The backhoe according to claim 4, wherein a concave portion 45 c that opens upward is formed at a rear portion of the outer standing portion 45 b in the attachment portion 45.

Images