JP2001260939A - Lower structure for rotary work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent pivotal support parts of a blade support arm and a lift actuator or the like from interfering with an obstacle when a motor truck frame is traveled over the obstacle such as a stone. SOLUTION: This motor truck frame 2 comprises a center part 3 supporting a rotary bearing 6 above, support leg parts 4 protruded to the right and left from the center part 3, and side parts 5 located at the end parts of the right and left support leg parts 4 to support crawler wound wheels 7. The blade support arm 9 and the lift actuator 10 of a bulldozer device 8 are pivotally supported at the front part of the center part 3, and the pivotal support parts of the blade support arm 9 and the lift actuator 10 are arranged higher than the bottom face of the central part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lower structure of a turning work machine such as a backhoe.

[0002]

2. Description of the Related Art In a turning work machine such as a backhoe,
A crawler traveling device is provided on the left and right of the track frame, a lower structure is provided with a dozer device on the front portion, a turning table is provided on the track frame via a swivel bearing, and a steering section and an excavating device etc. are provided on the swivel table. The upper structure is provided. The track frame has a center portion that supports a slewing bearing on an upper surface, a support leg portion that projects left and right from the center portion, and a side portion that is located at an end of each of the left and right support legs and supports a crawler-wrapped wheel. The blade support arm of the dozer device and the lifting actuator are pivotally supported at the front part of the center part.

[0003] The blade supporting arm and the lifting actuator are supported on the front surface of a center portion. In order to secure a distance between the pivoting points, the pivot point of the blade supporting arm is located below the lifting actuator, and a swivel joint is provided. Is projected below the center bottom surface of the center portion where is disposed.

[0004]

In the prior art, since the pivot portion of the blade support arm protrudes below the center bottom surface of the center portion, the track frame may straddle an obstacle such as a large stone or raised soil. If you run on the road, it may interfere with obstacles. The present invention provides a lower structure of a turning work machine in which each of the pivotal support portions of a blade support arm and an elevating actuator is arranged at a height equal to or higher than a bottom surface of a center portion so that interference with an obstacle can be avoided. The purpose is to:

According to the present invention, the pivot portion of the lifting actuator can be arranged at the front side, so that the pivot portion of the blade support arm can be arranged at a higher position, so that interference with obstacles can be avoided. An object of the present invention is to provide a lower structure of a turning work machine.

[0006]

A first concrete means for solving the problem in the present invention is that a slewing bearing 6 is provided on the upper surface.
, A support leg 4 protruding left and right from the center 3, and a side portion 5 located at an end of each of the left and right support legs 4 and supporting a crawler winding wheel 7. To form a track frame 2, and a blade support arm 9 of a dozer device 8 and a lifting actuator 10 are pivotally supported at a front portion of the center portion 3. Each pivot of the blade support arm 9 and the lifting actuator 10 is That is, it is arranged at a height higher than the bottom surface of the center portion 3.

[0007] Thus, even if the turning work machine runs across an obstacle such as a large stone or raised soil, the structure of the center section 3 does not interfere with the obstacle. The second specific means for solving the problem in the present invention is a center part 3 which supports a swivel bearing 6 on the upper surface, a support leg 4 projecting left and right from the center part 3, and a left and right support leg 4 A track frame 2 is formed having a side portion 5 supporting a crawler winding wheel 7 located at an end of the track frame 2. A blade support arm 9 of a dozer device 8 and a lifting actuator 10 are provided at a front portion of the center portion 3. And an upper plate 11 forming the upper surface of the center portion 3 is projected forward, and at least a vertical movement of the blade supporting arm 9 of the dozer device 8 and the lifting actuator 10 is provided on the lower surface side of the projecting portion of the upper plate 11. That is, the actuator 10 is pivotally supported, and the pivotal support portions of the blade support arm 9 and the lifting / lowering actuator 10 are arranged at a height higher than the bottom surface of the center portion 3.

Accordingly, even if the turning work machine runs 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
Can be realized with a simple configuration that only protrudes forward. The third concrete means for solving the problem in the present invention is the first concrete means.
Alternatively, in addition to the specific means of 2, the swivel joint 13 is disposed at the center of the center portion 3, and the lower cover body 53 for closing the lower portion of the swivel joint 13 is also used for attaching the swivel joint 13 to the center portion 3. That is.

Thus, the vertical dimension of the center portion 3 is reduced to increase the ground height, and interference with obstacles is reliably avoided.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 7 and 8, reference numeral 21 denotes a small back turning type backhoe exemplified as a turning work machine,
The backhoe 21 is mainly composed of a lower structure having a dozer device 8 and a left and right crawler traveling device 22 on the track frame 2, and an upper structure having a steering unit, a driving device, and an excavator 25 on a swivel 23. ing. The track frame 2 has a center portion 3 having a swivel joint 13 provided at the center and supporting a swivel bearing 6 on the upper surface, support legs 4 projecting left and right from the center portion 3, and ends of the left and right support legs 4. And a side portion 5 that supports the crawler wrapping wheel 7 and is located at the portion.

The crawler traveling device 22 is supported by the left and right side portions 5 of the track frame 2, and includes front and rear driving wheels 7A, driven wheels 7B, and a plurality of rolling wheels 7C therebetween.
A rubber or iron crawler 27 is wound around the crawler winding wheel 7, and the drive wheel 7A is driven by a traveling drive source such as a hydraulic motor. Further, the crawler traveling device 22 moves the driven wheel 7B to
Has a tension adjusting means 26 for adjusting the tension of. The dozer device 8 includes a blade support 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 support arm 9.
And a lifting actuator 10 for lifting and lowering the blade support arm 9.

The swivel table 23 is supported on the track frame 2 so as to be swivelable about a swivel axis X. The swivel table 23 includes an engine 28, a radiator 29, an oil tank 30, a fuel tank 31, a driver's seat 32, a steering device 33, and a ropes. A cabin device that carries the driver's seat 32 and the steering device 33 may be provided instead of the ropes 34. At the front of the swivel 3, the excavator 2 is mounted via a bracket 36.
5 is mounted so as to be swingable about the vertical axis. The excavator 25 includes a boom 38 and a boom cylinder 39 on a swing bracket 37 supported by the bracket 36 via a vertical axis.
Are pivotally supported at the distal end of the boom 38 and an arm 40 is pivotably supported by an arm cylinder 41.
A bucket (working tool) 42 is pivotally supported at the leading end of the cylinder cylinder 0 so that a bucket cylinder 43 can perform scooping and dumping operations.

1 to 8, the center portion 3 of the track frame 6 is formed in a square box shape by connecting an upper plate 11 and a lower plate 45 by front, rear, left and right vertical plates 46. The support legs 4 project 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 so as to project right and left outward and downward, respectively, to form a pair of upper and lower leg plates 47. They are connected by a plate 48 to form an I-shaped cross section or a quadrangular cylindrical section. The vertical leg connecting plates 48 of the left and right front support legs 4 are integrally formed with the front vertical plate 46 of the center portion 3 as a single plate, and the front vertical leg connecting plates 48 of the right and left rear support legs 4 are integrally formed.
Are integrally formed with the left and right vertical plates 46 of the center portion 3 and the U-shaped bent plate in a plan view, and the rear vertical leg connecting plates 48 of the left and right support legs 4 are provided on the rear side of the center portion 3. Vertical plate 46 and trapezoidal 2
It is preferable to integrally mold with a bent portion.

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

The upper surface of the support frame 49, which is substantially gate-shaped when viewed from the front, is inclined outward and downward so that the soil placed on the upper surface can be naturally discharged to the outside. Overlapping. 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 both the upper and lower sides. Inner ring is fixed. On the inner peripheral surface of the inner ring of the slewing bearing 6, a large gear is formed which meshes with a pinion 51 of a drive motor mounted on the slewing table 23.

On the inner surface side of the vertical plate 46 at the front and rear portions, a substantially inverted gate-shaped mounting body 52 as viewed from the front is disposed. It is preferable that at least the upper part of the mounting body 52 is fixed to the upper plate 11 and also fixed to the front and rear vertical plates 46. The front and rear attachment body 52 includes an outer cylinder 1 of the swivel joint 13.
A lower cover body 53 that seals the lower end of 3A is bolted. The lower cover body 53 has a drain hole 53A so that the internal leak oil can be discharged, and also functions as a mounting bracket for the swivel joint 13.
Bolt holes are provided at both front and rear ends for mounting to the front and rear mounting body 52.

The upper plate 11 is formed of a thicker plate than the lower plate 45, and the swivel joint 13 is connected to the lower plate 45.
It can be more firmly fixed to the upper plate 11 via the mounting body 52 than to be mounted on the upper plate 11. The lower cover body 53
By using the mounting bracket of the swivel joint 13 as well, the vertical height of the center portion 3 can be reduced as compared with the case where the lower cover and the mounting bracket are separately provided, 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 section 3 can be increased.

The swivel joint 13 has an upper part of the swivel shaft 13B connected to the swivel base 23 and connected to a hydraulic pump. The swivel joint 13 is moved from the upper structure side to the lower structure side via an oil passage between the swivel shaft 13B and the outer cylinder 13A. Pressure oil supply. The outer ring of the swivel bearing 6 is fixed to the swivel 23. Reference numeral 12 denotes a bottom plate mounted on the lower plate 45 from below, which closes a swivel joint insertion hole of the lower plate 45 from below to prevent water and dust from entering. This bottom plate 12 is located at the lowest position of the center portion 3 and forms a bottom surface.

The sturdy upper plate 11 of the center portion 3 has a protruding portion 11A which protrudes forward more than the front vertical plate 46, and the lower surface of the protruding portion 11A has a blade support arm 9 of the dozer device 8 mounted thereon. A bracket 55 for supporting the pivot portion of
A bracket 56 that supports the pivotal support of the lifting actuator 10 is attached. The brackets 55 and 56
Is fixed to the front surface of the vertical plate 46 in the prior art,
Because of the strength, the projecting amount from the vertical plate 46 could not be increased, so that the pivot portion of the elevation actuator 10 was located near the vertical plate 46 and the pivot portion of the blade support arm 9 was
It protrudes further downward to secure a distance from the pivot of the lifting actuator 10.

However, as described above, by protruding the protruding portion 11A of the upper plate 11 greatly, the pivot portion of the lifting / lowering actuator 10 is changed to the front position, whereby the pivot portion of the blade support arm 9 is moved upward. You can change the position. And the pivot portion of the blade support arm 9 is
By changing the position upward, it does not protrude below 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 prevented. Will not come into contact with

In other words, in order to avoid interference with an obstacle, the position of the pivot of the blade support arm 9 is changed upward to secure a distance between pivot points for swinging the blade support arm 9. , The pivot of the lifting actuator 10 is repositioned forward and such a blade support arm 9 is moved.
And to firmly support the lifting actuator 10,
The upper plate 11 protrudes greatly forward. As shown in FIGS. 2 and 3, the bottom plate 12 forming the lowermost surface of the center portion 3 is located at substantially the same height as the upper surface of the substantially frame-shaped support frame 49 of the side portion 5 when viewed from the front. A space 17 for stacking two step boards is secured below.

This is, as described above, the lower cover 53
The height of the center section 3 is made higher by also functioning as a mounting bracket for the swivel joint 13. When the backhoe 21 is loaded on a truck bed, two sheets are provided below the center section 3. The step plates 59 can be arranged in an overlapping manner. The step board 59 may be made of metal, but is usually made of wood. If the thickness of the two pieces is about the height of the upper surface of the support frame 49, the backhoe 21 for getting on and off the truck bed can be used. The vertical dimension of the center part 3 is reduced and the support legs 4 are sharpened so that two step plates 59 can be placed under the center part 3 by stacking two step plates 59. It is inclined at an angle.

The holes formed in the protruding portion 11A of the upper plate 11 are holes for reducing the weight, and the pivotal support portions of the blade supporting arm 9 and the lifting / lowering actuator 10 are provided with brackets 55 and 56.
The pins 55A and 56B are inserted from the left and right directions and 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 bracket 55 from the left and right sides. Instead, only one sheet is provided on the center side to form an I-shaped cross section, and a pin insertion space is formed on the front side.

The dozer device 8 has a blade 14 fixed to the tips of two blade supporting arms 9 and
The front end of the lifting actuator 10 is connected to a connection bracket 58 fixed to the back of the blade, and the blade support arm 9 is swung so that the blade 14 moves up and down by the operation of the lifting actuator 10. A reinforcing plate 15 is fixed by welding to a corner formed by the outer end of the left and right blade support arm 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. As shown in FIG. 6, one side fixed to the blade support arm 9 is inclined rearward and downward from the blade 14 side.
Is inclined outward and downward from the blade support arm 9, and the rear side is positioned substantially horizontally.

By inclining the reinforcing plate 15 backward and sideways (three-dimensionally inclined) in this way, even if it is a single triangular flat plate, it is possible to eliminate the debris on the triangular flat plate to the rear side. It can be manufactured at low cost while firmly reinforcing. A connecting bracket 5 is provided on the back surface of the blade 14 between the inner surfaces of the left and right blade supporting arms 9.
8 and an intermediate reinforcing plate 16 between them.
The intermediate reinforcing plate 16 may be formed as a flat plate and fixed to the blade 14 in a rearwardly downwardly inclined shape. ing.

The elevating actuator 10 is formed of a hydraulic cylinder and has a cover 60 for protecting the cylinder rod. Note that the present invention is not limited to the above embodiment, and can be variously modified. For example, the pivot of the blade support arm 9 is
6, the bracket 55 is attached to the vertical plate 46.
And only the pivot bracket 56 of the lifting actuator 10 may be attached to the upper plate protrusion 11A.

[0027]

According to the present invention, the structure of the center section 3 interferes with obstacles even when the turning work machine runs over obstacles such as large stones and raised soil. There is no.

[Brief description of the drawings]

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

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

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

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 an overall rear view of the same.

[Explanation of symbols]

 Reference Signs List 2 track frame 3 center part 4 support leg part 5 side part 6 swivel bearing 7 wheel 8 dozer device 9 blade support arm 10 elevating actuator 11A projecting part 11 upper plate 12 bottom plate 17 stepping plate 2 overlapping arrangement space 21 backhoe (rotating work machine) 22) Crawler traveling device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Yamashita 64, Ishizukita-cho, Sakai City, Osaka Prefecture Inside the Kubota Sakai Plant (72) Inventor Toshinori Ichikawa 64, Ishizukitacho, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. Inside

Claims (3)

[Claims] 1. A center portion for supporting a slewing bearing on an upper surface, a support leg protruding left and right from the center portion, and a side portion positioned at an end of each of the left and right support legs to support a crawler-wrapped wheel. A track frame is formed, and a blade support arm of a dozer device and an elevating actuator are pivotally supported at a front portion of the center portion. Each pivot portion of the blade support arm and the elevating actuator is connected to a bottom surface of the center portion. The lower structure of the turning work machine is characterized by being arranged at the above height. 2. A center portion for supporting a slewing bearing on an upper surface, a support leg projecting left and right from the center portion, and a side portion which is located at an end of each of the left and right support legs and supports a crawler-wrapped wheel. A track frame is formed, and a blade support arm and a lifting actuator of a dozer device are pivotally supported at a front portion of the center portion, and an upper plate forming an upper surface of the center portion is projected forward, and At least the lifting actuator of the blade support arm and the lifting actuator of the dozer device is pivotally supported on the lower surface side of the protrusion,
The lower structure of a turning work machine, wherein each of the pivotal support portions of the blade support arm and the lifting actuator is disposed at a height equal to or higher than a bottom surface of a center portion. 3. A swivel joint is disposed at the center of the center portion, and a lower cover body closing a lower portion of the swivel joint is also used for attaching the swivel joint to the center portion. 3. The lower structure of the turning work machine according to 2.