JP3514693B2 - Undercarriage structure of turning machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower structure of a swing working machine such as a backhoe.

[0002]

2. Description of the Related Art In turning machines such as backhoes,
The track frame is equipped with a crawler traveling device on the left and right sides, a dozer device is provided in the front part to form a lower structure, and a swivel base is provided on the track frame via a swivel bearing. The upper structure is configured in preparation. The track frame has a center portion for supporting a slewing bearing on an upper surface thereof, a support leg portion protruding leftward and rightward from the center portion, and a side portion for supporting a crawler-wrapped wheel at an end portion of each of the left and right support leg portions. And a blade supporting arm and a lifting actuator of the dozer device are pivotally supported on the front portion of the center portion.

The blade support arm and the elevating actuator are supported on the front surface of the center portion, and in order to secure a distance between the pivot points, the pivot point of the blade supporting arm is located below the elevating actuator, and the swivel joint. Is projected downward from the center bottom surface of the center portion in which is arranged.

[0004]

In the above prior art, since the pivotal support portion of the blade support arm projects below the central bottom surface of the center portion, the track frame should straddle obstacles such as large stones and raised soil. It may interfere with obstacles when you drive to. The present invention provides a lower structure of a swivel work machine in which the blade support arm and the pivotal support portions of the lifting actuator are arranged at a height higher than the bottom surface of the center portion to avoid interference with obstacles. The purpose is to

According to the present invention, the pivotal support portion of the lift actuator can be disposed on the front side, so that the pivotal support portion of the blade support arm can be disposed above and interference with an obstacle can be avoided. An object is to provide a lower structure for a swing working machine.

[0006]

A first specific means for solving the problems in the present invention is a slewing bearing 6 on the upper surface.
A center portion 3 for supporting the vehicle, a support leg portion 4 protruding leftward and rightward from the center portion 3, and a side portion 5 positioned at an end portion of each of the left and right support leg portions 4 for supporting the crawler winding wheel 7. To form a track frame 2, and a blade support arm 9 of the dozer device 8 and a lift actuator 10 are pivotally supported on the front portion of the center portion 3, and the blade support arm 9 and the lift actuator 10 are pivotally supported. It is arranged at a height higher than the bottom surface of the center portion 3.

Thus, even if the turning work machine travels over an obstacle such as a large stone or raised soil, the structure of the center portion 3 does not interfere with the obstacle. A second specific means for solving the problem in the present invention is a center portion 3 for supporting a slewing bearing 6 on an upper surface, a support leg portion 4 protruding left and right from the center portion 3, and left and right support leg portions 4 respectively. Forming a track frame 2 having a side portion 5 positioned at an end portion thereof for supporting a crawler-wound wheel 7, and a blade supporting arm 9 of a dozer device 8 and a lifting actuator 10 in front of the center portion 3. And an upper plate 11 forming the upper surface of the center part 3 are projected forward, and at least the lifting / lowering of the blade support arm 9 and the lifting actuator 10 of the dozer device 8 is performed on the lower surface side of the projecting part of the upper plate 11. The actuator 10 is pivotally supported, and each of the pivot support portions of the blade support arm 9 and the lift actuator 10 is arranged at a height higher than the bottom surface of the center portion 3.

As a result, even when the turning work machine travels over an obstacle such as a large stone or raised soil, the structure of the center portion 3 does not interfere with the obstacle, and the upper plate 11 is provided.
It can be realized with a simple configuration in which the front part is projected. The third concrete means for solving the problems in the present invention is the first
Alternatively, in addition to the specific means of 2, the swivel joint 13 is arranged in the center of the center part 3, and the lower cover body 53 that closes the lower part of the swivel joint 13 is also used for attaching the swivel joint 13 to the center part 3. It is that.

As a result, the vertical dimension of the center portion 3 is reduced to increase the ground clearance, and interference with obstacles is reliably avoided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 7 and 8, 21 is a rear small turning type backhoe, which is illustrated as a turning work machine,
The backhoe 21 is mainly composed of a lower structure including a dozer device 8 and left and right crawler traveling devices 22 on the track frame 2, and an upper structure including a swivel base 23 including a control unit, a driving device, and an excavating device 25. ing. The track frame 2 supports a slewing bearing 6 on the upper surface thereof and a center portion 3 provided with a swivel joint 13 in the center, a support leg portion 4 protruding leftward and rightward from the center portion 3, and ends of the left and right support leg portions 4 respectively. And a side portion 5 that is located at a position to support the crawler-wrapped wheel 7.

The crawler traveling device 22 is supported by the left and right side portions 5 of the track frame 2, and has front and rear drive wheels 7A, driven wheels 7B, and a plurality of rolling wheels 7C therebetween.
A crawler 27 made of rubber or iron is wound around a crawler winding wheel 7 such as the above, and the drive wheel 7A is driven by a traveling drive source such as a hydraulic motor. In addition, the crawler traveling device 22 moves the driven wheel 7B to move the crawler 27.
It has a tension adjusting means 26 for adjusting the tension. The dozer device 8 includes a blade supporting arm 9 protruding forward from the center portion 3 of the track frame 2 and a blade 14 fixed to a front end of the blade supporting arm 9.
And an elevating actuator 10 for elevating the blade supporting arm 9.

The revolving base 23 is supported by the truck frame 2 so as to be revolvable about a revolving axis X, and has an engine 28, a radiator 29, an oil tank 30, a fuel tank 31, a driver's seat 32, a control device 33 and a lops. A cabin device that mounts 34 or the like and surrounds the driver's seat 32 and the control device 33 may be provided instead of the lops 34. The excavator 2 is attached to the front part of the swivel base 3 via a bracket 36.
5 is mounted so as to be swingable about the vertical axis. The excavator 25 includes a swing bracket 37 supported by the bracket 36 via a vertical axis, a boom 38, and a boom cylinder 39.
Of the arm 38 is pivotally supported at the tip of the boom 38 so that the arm cylinder 41 can swing.
A bucket (work implement) 42 is pivotally supported at the tip of 0, and the bucket cylinder 43 enables scooping and dumping operations.

1 to 8, the center portion 3 of the track frame 6 is formed in a rectangular box shape by connecting an upper plate 11 and a lower plate 45 with vertical plates 46 on the front, rear, left and right sides. The support leg portion 4 projects a pair of upper and lower leg plates 47 from the front and rear portions of the left and right side edges of the upper and lower plates 11 and 45 of the center portion 3 to the outside of the left and right, respectively, and projects downward. The plates 48 are connected to each other to have an I-shaped cross section or a rectangular tubular cross section. The vertical leg connecting plate 48 of the left and right front supporting legs 4 is integrally formed with the front vertical plate 46 of the center part 3 by a single plate, and the front vertical leg connecting plate 48 of the left and right rear supporting legs 4 is formed.
Is integrally formed with the left and right vertical plates 46 of the center portion 3 by a bent plate having a dogleg shape in plan view, and the rear vertical leg connecting plates 48 of the left and right rear support legs 4 are the rear side of the center portion 3. Vertical plate 46 and trapezoidal 2
It is preferable to integrally form the bent plate at each point.

The left and right support legs 4 have a front leg extending outward and a rear leg extending rearward, and the front and rear legs may be separated and independent on the side of the center 3. However, it may be formed so as to form an integral U-shaped leg portion at the front and rear. Further, the left and right support leg portions 4 may be integrally formed without distinguishing the front and rear. Each of the left and right side portions 5 has a support frame 49 having a substantially gate-shaped front view fixed to the outer ends (free ends) of the upper and lower leg plates 47 located in the front and rear and the vertical leg connecting plates 48 connecting the same. A support bracket 50 for driving wheels is fixedly formed at the rear end.

The upper surface of the substantially frame-shaped support frame 49 as seen from the front is inclined outward and downward, so that the soil placed on it can be naturally discharged outward, and the outer end of the upper leg plate 47 is They overlap. In the center section 3,
A large circular hole is formed in the center of the upper plate 11 and the lower plate 45, and the swivel joint 13 can be inserted and arranged from either the upper side or the lower side. On the upper surface of the upper plate 11, the slewing bearing 6 is provided outside the circular hole. The inner ring of is stuck. On the inner peripheral surface of the inner ring of the slewing bearing 6, a large gear with which a pinion 51 of a drive motor attached to the slewing base 23 meshes is formed.

On the inner surface side of the front and rear vertical plates 46, a mounting body 52 having a substantially inverted gate shape in front view is arranged. It is preferable that at least an upper portion of the mounting body 52 be fixed to the upper plate 11 and also be fixed to the front and rear vertical plates 46. The front and rear mounting bodies 52 include the outer cylinder 1 of the swivel joint 13.
A lower cover body 53 that seals the lower end of 3A is fixed by bolts. The lower cover body 53 has a drain hole 53A to discharge internal leak oil and also serves as a mounting bracket for the swivel joint 13.
The front and rear ends have bolt holes for attaching to the front and rear mounting body 52.

The upper plate 11 is formed of a plate material thicker than the lower plate 45, and the swivel joint 13 is formed on the lower plate 45.
Rigid support can be achieved by fixing to the upper plate 11 via the mounting body 52, rather than by mounting on the upper plate 11. The lower cover body 53
Is also used as a mounting bracket for the swivel joint 13, the vertical height of the center portion 3 can be shortened as compared with the case where the lower cover and the mounting bracket are provided separately, and if the height of the upper plate 11 is constant. The height of the bottom surface can be increased, and the ground height of the center portion 3 can be increased.

In the swivel joint 13, the upper part of the swivel shaft 13B is connected to the swivel base 23 and is connected to a hydraulic pump, and the upper structure side to the lower structure side are connected via an oil passage between the swivel joint 13 and the outer cylinder 13A. It is possible to supply pressure oil to. The outer ring of the swivel bearing 6 is fixed to the swivel base 23. A bottom plate 12 is attached to the lower plate 45 from below, and the swivel joint insertion hole of the lower plate 45 is closed from below to prevent water and dust from entering. The bottom plate 12 is located at the lowermost position of the center portion 3 and forms the bottom surface.

The sturdy upper plate 11 of the center portion 3 has a protruding portion 11A that protrudes forward more than the front vertical plate 46. The blade supporting arm 9 of the dozer device 8 is provided on the lower surface of the protruding portion 11A. A bracket 55 for supporting the pivotal support of
A bracket 56 that supports a pivot portion of the lifting actuator 10 is attached. The brackets 55, 56
Is fixed to the front surface of the vertical plate 46 in the prior art,
Since the amount of protrusion from the vertical plate 46 could not be increased in terms of strength, the pivotal support portion of the lift actuator 10 is located near the vertical plate 46, and the pivotal support portion of the blade support arm 9 is located at the bottom plate 12.
It was designed to project further downward and to secure a distance from the pivotal support of the lift actuator 10.

However, as described above, the protrusion 11A of the upper plate 11 is largely protruded to change the position of the pivotal support of the lift actuator 10 to the front, whereby the pivotal support of the blade support arm 9 is moved upward. You can change the position. And, the pivotal support of the blade support arm 9 is
By changing the position to the upper side, it does not project downward from the bottom plate 12, that is, it can be arranged at a height higher than the bottom surface of the center portion 3, and when the track frame 2 straddles an obstacle such as a stone, the obstacle is blocked. Will no longer be in contact with.

In other words, in order to avoid interference with obstacles, the pivotal support portion of the blade support arm 9 is repositioned upward, and a distance between pivotal support points for swinging the blade support arm 9 is secured. , The pivotal support of the lift actuator 10 is repositioned forward, such blade support arm 9
In order to firmly support the lifting actuator 10,
The upper plate 11 is largely projected forward. As shown in FIGS. 2 and 3, the bottom plate 12 that forms the lowermost surface of the center portion 3 is located at substantially the same height as the upper surface of the support frame 49 that is substantially gate-shaped in front view of the side portion 5. A space 17 for stacking two walking boards is secured below.

As described above, this is the lower cover body 53.
This is made possible by making the swivel joint 13 also serve as a mounting bracket to raise the ground height of the center part 3, and when the backhoe 21 is loaded on the truck bed, two pieces are placed below the center part 3. The walking boards 59 can be arranged in an overlapping manner. The walk board 59 may be made of metal, but is usually made of wood. If the walk board 59 is thick enough to reach the height of the upper surface of the support frame 49 with two pieces, the backhoe 21 for getting on and off the truck bed can be used. The vertical dimension of the center portion 3 is made thin and the support leg portions 4 are abruptly arranged so that two walking boards 59 can be placed under the center portion 3 so as to be placed under the center portion 3. It is tilted at an angle.

The hole formed in the protruding portion 11A of the upper plate 11 is a hole for reducing the weight, and the pivotal support portions of the blade support arm 9 and the lifting actuator 10 are brackets 55, 56.
The pins 55A and 56B are inserted from the left and right directions to be connected. As shown in FIG. 5, the vertical leg connecting plates 48 of the left and right front support legs 4 are provided along the front and rear of the support legs 4 so that the pins 55A can be inserted into the brackets 55 from the left and right sides. Instead, only one piece is provided on the center side to form an I-shaped cross section, and a pin insertion space is formed on the front side thereof.

In the dozer device 8, the blades 14 are fixed to the tips of the two blade supporting arms 9,
The tip of the lift actuator 10 is connected to a connecting bracket 58 fixed to the back surface of the blade support arm 9, and the blade support arm 9 is swung so that the blade 14 moves up and down by the operation of the lift actuator 10. A reinforcing plate 15 is fixed by welding to a corner formed by the tip of the outer surface of the left and right blade support arms 9 and the back surface of the blade 14. The reinforcing plate 15 is a flat plate having a substantially triangular shape in a plan view, and as shown in FIG. 6, one side fixed to the blade supporting arm 9 is inclined rearward and downward from the blade 14 side.
The one side fixed to is tilted outward and downward from the blade support arm 9, and the rear side is positioned substantially horizontally.

In this way, by tilting the reinforcing plate 15 backward and laterally downward (three-dimensional inclination), even if it is a single triangular flat plate, the debris on it can be removed to the rear side. It is possible to manufacture it at low cost while firmly reinforcing it. Further, on the back surface of the blade 14 between the inner side surfaces of the left and right blade support arms 9, the connecting bracket 5
8 and an intermediate reinforcing plate 16 between them.
The intermediate reinforcing plate 16 may be formed of a flat plate and fixed to the blade 14 in a rearward and downward slanted shape. However, the flat plate is bent in a V shape in a side view and attached so that the upper surface thereof is in the rearward and downward slanted shape. ing.

The elevating actuator 10 is formed of a hydraulic cylinder and has a cover 60 for protecting the cylinder rod. The present invention is not limited to the above-mentioned embodiment, but can be modified in various ways. For example, the pivotal support of the blade support arm 9 is the vertical plate 4
6 can be arranged near the vertical plate 46.
Alternatively, only the bracket 56 for pivoting the lifting actuator 10 may be attached to the upper plate protrusion 11A.

[0027]

According to the present invention described in detail above, even if the turning work machine travels over an obstacle such as a large stone or raised soil, the structure of the center portion 3 interferes with the obstacle. There is no.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional side view of the main part.

FIG. 3 is a front view of the same section.

FIG. 4 is a plan view of the same.

FIG. 5 is an enlarged plan view of the main part.

FIG. 6 is a perspective view of a dozer device.

FIG. 7 is an overall side view of the backhoe.

FIG. 8 is a rear view of the same.

[Explanation of symbols]

2 track frames 3 Center 4 Support legs 5 side parts 6 Slewing bearing 7 wheels 8 Dozer device 9 Blade support arm 10 Lifting actuator 11A protrusion 11 Upper plate 12 Bottom plate 17 Two walking boards stacking space 21 Backhoe (turning work machine) 22 Crawler traveling device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshinori Ichikawa 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Works (56) References JP-A-11-278300 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B62D 21/18 E02F 3/815 E02F 9/06

Claims (3)

(57) [Claims] 1. An upper plate and a lower plate are connected by front, rear, left and right vertical plates.
And the center part that supports the slewing bearing on the upper surface of the upper plate ,
A support leg portion projecting from the center portion to the left and right, and a side portion for supporting the crawler winding wheel to form a track frame located on the edge portion of the left and right support legs, wherein
A swivel joint is arranged in the center of the center part, and a blade support arm of the dozer device and a lifting actuator are pivotally supported at the front part of the center part to form an upper surface of the center part.
Is formed as a thicker plate than the lower plate and protrudes forward,
Attach the mounting body to at least the upper plate of the vertical plates,
Attach the lower end of the outer cylinder of the swivel joint to the attachment body.
Attach the cover to support the swivel joint,
A blade support arm of the dozer device is attached to the lower surface of the protruding portion of the upper plate.
At least the lifting actuation of the
A lower structure of a swivel work machine , wherein a blade supporter is pivotally supported, and each of the blade support arm and each of the pivotal support portions of the lifting actuator is disposed at a height higher than a bottom surface of a center portion. 2. An upper plate and a lower plate are connected by front, rear, left and right vertical plates.
And the center part that supports the slewing bearing on the upper surface of the upper plate ,
A support leg portion projecting from the center portion to the left and right, and a side portion for supporting the crawler winding wheel to form a track frame located on the edge portion of the left and right support legs, wherein
A swivel joint is arranged in the center of the center part, and a blade support arm of the dozer device and a lifting actuator are pivotally supported at the front part of the center part to form an upper surface of the center part.
Is formed as a thicker plate than the lower plate and protrudes forward,
Attached to the front and rear parts of the vertical plate is an inverted gate-shaped mounting body when viewed from the front.
Then, attach the lower end of the outer cylinder of the swivel joint to this mounting body.
Attach the lower cover to seal and attach the swivel joint.
The dozer device is supported on the lower surface side of the protruding portion of the upper plate.
At least one of the support arm and the lifting actuator.
A lower structure for a swivel work machine , wherein an elevation actuator is pivotally supported, and each of the blade support arm and each pivot support portion of the elevation actuator is arranged at a height higher than a bottom surface of a center portion. 3. A drain hole is formed in the lower cover,
Form a swivel joint insertion hole in the lower plate below
Lower the bottom plate that closes the swivel joint insertion hole to the bottom plate.
The lower structure of the swing working machine according to claim 1 or 2, wherein the lower structure is mounted from the bottom.