JPH07259120A - Float device for dozer blade - Google Patents

Abstract

PURPOSE:To enable the levelling operation of a ground only by dozer blade itself by forming projecting sections to boss sections at both ends of a hydraulic cylinder, forming recessed groove sections on the bracket side in response to the projecting sections and movably inserting and guiding the projecting sections. CONSTITUTION:A dozer blade 16 is mounted rotatably on a bracket 19 fixed onto a lower frame 16 in the vertical direction, one boss section of a hydraulic cylinder 17 is attached pivotally to the bracket of the dozer blade 16, the other boss section is installed to a bracket 20 through a pin 18, and the dozer blade 16 is lifted and lowered. Elliptical-shaped recessed groove sections 21, 22 are formed to the faced internal surface sections of the bracket 20, and projecting sections 23, 24 shaped to the boss sections of the hydraulic cylinder 17 are held in a reciprocative manner in the longitudinal direction of the recessed groove sections 21, 22, thus forming the state of the float of the dozer blade 16. The pin 18 is inserted and normal dozer operation is conducted, and float operation is performed when no pin 18 is inserted. Since the hydraulic cylinder is not expanded on contracted under the state of the float of the dozer blade and have no pipeline resistance, the levelling work of the ground is enabled only by the weight of the dozer blade.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly applied to an upper turning construction machine such as a hydraulic excavator and a vehicle equipped with a work vehicle.
The device.

[0002]

2. Description of the Related Art FIG. 8 is a side view of a hydraulic excavator equipped with a dozer device. In the figure, 1 is an upper revolving structure, 2
Is a working device, 3 is a lower traveling body, 4 is a dozer device, 5 is a driver's cab, and 6 is a machine room in which an engine / hydraulic device (not shown) and the like are arranged. FIG. 9 shows the actual Kaihei 1-1600.
It is a principal part circuit diagram of the blade control circuit of the bulldozer described in Japanese Patent No. 55. In the circuit diagram of FIG. 9, the blade is “up”, “retained”,
The oil passages 13 and 14 are connected and disconnected in the middle of the oil passages 13 and 14 that respectively connect the three-position switching valve 7 that is held in the “down” state and the bottom side chamber 9 and the rod side chamber 10 of the hydraulic cylinder 8. An electromagnetic switching valve 11 is provided for this purpose. As a result, when the selection switch 12 is turned on, the electromagnetic switching valve 11
Is activated, the oil passages 13 and 14 are brought into conduction, and the hydraulic cylinder 8
Is released so that the blade controlled by the hydraulic cylinder 8 is in a floating state.

[0003]

When the blade control circuit of the prior art is used in an upper swing type construction / working machine such as a hydraulic excavator, an electromagnetic switching valve arranged in the upper swing body is passed through a swivel joint. , The door mounted on the undercarriage
Since the pipeline leading to the hydraulic cylinder for lifting and lowering the Zablade is long, the pipeline resistance increases. For this reason, even if the dozer blade is in the floating state, the pipe resistance has a great influence, and the ground leveling work cannot be performed only by the weight of the dozer blade, so that the work efficiency is lowered. In addition, the solenoid switching valve and hydraulic piping will need to be added and remodeling work will be required, resulting in higher costs. When an electromagnetic switching valve is installed on the lower traveling structure to reduce the line resistance, a slip ring for electrical wiring from the operation panel installed on the upper revolving structure to the electromagnetic switching valve installed on the lower traveling structure. Will be required and the cost will increase.
SUMMARY OF THE INVENTION An object of the present invention is to provide a dozer blade float device which can solve the above problems.

[0004]

In order to achieve the above object, in the float apparatus for a dozer blade of the present invention, either one of the boss portions at both ends of a hydraulic cylinder for raising and lowering the dozer blade is provided. A protrusion on the bracket, and a groove corresponding to the protrusion on the side of the bracket to loosely insert the protrusion.
I tried to let you know.

The protrusions are circularly and symmetrically formed coaxially with the pin mounting holes on the left and right side surfaces of either one of the bosses on both ends of the hydraulic cylinder, and the recessed grooves are used for mounting the bosses. The brackets are formed so that the inner surface portions facing each other have a width slightly larger than the diameter of the protruding portion, and the pin mounting holes formed in the bracket are located in the concave groove portions.

A bush having a length longer than the width of the boss portion is inserted through the boss portion of the hydraulic cylinder, and protrusions are formed on both left and right sides of the boss portion.

[0007]

In the float device constructed as described above, the boss portions at both ends of the hydraulic cylinder for raising and lowering the dozer blade are connected to the lower traveling body and the dozer blade during normal dozer work. Since the brackets are fixed to the brackets fixed to each other via pins, the dozer blade can be moved up and down by expanding and contracting the hydraulic cylinder. Further, since one of the bosses of the hydraulic cylinder and the bracket corresponding thereto are provided with the protrusions and the recessed groove portions, and the protrusions are loosely inserted and guided in the recessed groove portions, the protrusions are not removed even if the pin is removed. Since it is supported by the concave groove portion of the bracket and can move in the front-rear direction, the float state of the dozer blade is formed. Therefore, when the dozer blade moves up and down due to the unevenness of the ground, the projecting portion reciprocates in the concave groove portion correspondingly. At this time, since the hydraulic cylinder does not expand and contract and resistance in the pipeline does not occur, the ground leveling work can be performed only by the weight of the dozer blade, and thus the work efficiency is good and the ground leveling work with a good finish can be performed.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a side view of a main part of a dozer apparatus provided with a float device according to claims 1 and 2 of the present invention. In the figure, 15 is a lower frame forming the lower traveling body,
Reference numeral 16 is a dozer blade, 17 is a hydraulic cylinder for raising and lowering the dozer blade 16, 18 is a pin, and 19 and 20 are brackets fixed to the lower frame 15. 2 is shown in FIG.
It is a principal part top view seen from A of FIG. FIG. 3 shows BB of FIG.
It is the partial cutaway side view seen further. FIG. 4 is a partially cutaway sectional view seen from C of FIG. In the drawing, reference numerals 21 and 22 denote concave groove portions formed on the inner surface portions of the bracket 20 which face each other, and
Reference numerals 3 and 24 are protrusions formed on the boss portion of the hydraulic cylinder 17. FIG. 5 is a partially cutaway sectional view similarly seen from C of FIG. 3, showing the float state of the dozer blade 16. In this embodiment, as shown in FIGS. 1 and 2, the lower frame 1
The dozer blade 16 is attached to a bracket 19 fixed to the No. 5 so as to be vertically rotatable, and one boss portion of the hydraulic cylinder 17 is pivotally attached to the bracket of the dozer blade 16 and the other boss portion is pivotally attached. The portion is attached to the bracket 20 via the pin 18 so that the dozer blade 16 can be moved up and down. As shown in FIGS. 3 to 5, elliptical concave grooves 21 and 22 are formed on the inner surface portions of the bracket 20 which face each other, and the projections 23 and 24 formed on the boss portion of the hydraulic cylinder 17 are formed on the concave groove portions. The floats of the dozer blade 16 are formed by holding the 21, 22 so that they can reciprocate in the longitudinal direction. That is, as shown in FIG. 4, if the pin 18 is inserted and attached, a normal dozer work is performed, and as shown in FIG.
If 8 is not inserted, it becomes a float work.

FIG. 6 is a partially cutaway plan view of the float device according to claim 3 of the present invention. In the figure, 25 is a hydraulic cylinder for raising and lowering the dozer blade 16, and 26 is a bush inserted through the boss portion of the hydraulic cylinder 25. As shown in FIG. 6, in this embodiment, a bush 26 having a length larger than the boss width is inserted into a boss portion of the hydraulic cylinder 25 to form a protrusion portion, and the protrusion portion is formed into the concave groove portions 21 and 22. The hydraulic cylinder 25, that is, the dozer blade 16, is held in such a manner that it can be moved in the front-rear direction.

Further, as shown in FIG. 7, a hydraulic cylinder 28 is provided on the axial center of the pin mounting hole of the bracket 27, and the hydraulic cylinder 17 is attached to the bracket 27 via a rod 29 thereof.
There is also a way to make it pivot.

[0011]

The float device of the present invention is a dozer blade.
The floater state of the dozer blade is created by removing the mounting pin on the lower frame side of the hydraulic cylinder for lifting and lowering the door and removing the restraint at one end of the hydraulic cylinder. Therefore, when performing ground leveling work using the float,
When the dozer blade moves up and down due to the unevenness of the ground, there is no expansion or contraction of the hydraulic cylinder, so there is no influence of the line resistance, and therefore the float state can be obtained only by the dead weight of the dozer blade. As a result, the ground leveling work can be performed efficiently and with a good finish. In addition, there is no need to add or remodel the electromagnetic switching valve and hydraulic piping, and the cost can be reduced. Further, if a hydraulic cylinder is used for attaching and detaching the hydraulic cylinder mounting pin for raising and lowering the dozer blade, the pin can be easily attached and detached from the driver's seat, which is even more convenient.

[Brief description of drawings]

FIG. 1 is a side view of an essential part of a dozer apparatus provided with a float device according to claims 1 and 2 of the present invention.

FIG. 2 is a plan view of an essential part seen from A in FIG.

FIG. 3 is a side sectional view taken along the line BB of FIG.

FIG. 4 is a partially cutaway cross-sectional view seen from C of FIG.

5 is a partially cutaway cross-sectional view seen from C of FIG. 3, showing a floating state.

FIG. 6 is a partially cutaway plan view of the float device according to claim 3 of the present invention.

FIG. 7 is a partially cutaway plan view of a float device according to another embodiment of the present invention.

FIG. 8 is a side view of a main part of a hydraulic excavator equipped with a dozer device.

FIG. 9 is a circuit diagram of a main part of a blade control circuit of a conventional bulldozer.

[Explanation of symbols]

 7 3-position switching valve 8, 17, 25, 28 Hydraulic cylinder 11 Electromagnetic switching valve 13, 14 Hydraulic line 15 Lower frame 16 Dozer blade 18 Pin 19, 20, 27 Bracket 26 Bush 21, 22 Recessed groove

Claims (3)

[Claims] 1. A bracket mounted on the undercarriage is mounted on the bracket.
The zablade is connected so as to be vertically rotatable, and both end bosses of the hydraulic cylinder are pivotally attached to the bracket fixed to the dozerblade and the lower traveling body through pins, respectively. -In a dozer device for an upper-slewing construction / work machine in which the blade is raised and lowered, a protrusion is provided on either one of the bosses on both ends of the hydraulic cylinder, and the protrusion is provided corresponding to the protrusion. A floater device for a dozer blade, characterized in that a recessed groove portion is provided on the side of the bracket so that the protruding portion is loosely inserted and guided. 2. The projecting portion is formed on both left and right side surface portions of either end boss portion of the hydraulic cylinder so as to be circular and symmetrical coaxial with the pin mounting hole, and the recessed groove portion is mounted on the boss portion. Characterized in that it is formed in a width slightly larger than the diameter of the protruding portion on the inner surface portions of the bracket for use as opposed to each other, and the pin mounting hole formed in the bracket is located in the concave groove portion. The device according to claim 1,
Zablade float device. 3. A boss portion of the hydraulic cylinder is inserted with a bush having a length larger than a width dimension of the boss portion to form protrusions on both left and right side portions of the boss portion. The dozer blade float device described in 2.