JPS6242995Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention includes a dozer device attached to a vehicle body equipped with a swivel base, and a pump provided on the swivel base via a rotary joint interposed between the swivel base and the vehicle body. The present invention relates to piping for an earthmoving vehicle in which a pair of left and right lifting hydraulic cylinders of the dozer device are connected in parallel.

Conventionally, to configure the piping of the above-mentioned earthmoving vehicle,
As shown in FIG. 4, two channels 12a and 12b for dozer are formed in the rotary joint 3,
Each of the flow passages 12a and 12b is opened at the lower end of the rotary joint 3 on the vehicle body side, and a pair of pipes 15a and the opening of the rotary joint 3 are respectively connected to the bottom side chambers of both lifting hydraulic cylinders 7. The pipe 16a connected to one of them is connected by a three-way joint 17, and the rod side chambers of both hydraulic cylinders 7 and the other opening of the rotary joint 3 are connected to a pipe 15b with the three-way joint 17 interposed therebetween. , 16b, but
Since two expensive three-way joints 17 are required, there is a disadvantage in terms of the cost of the entire piping structure. Supporting fittings for the joints are required, and the number of parts increases, which reduces the efficiency of manufacturing and assembly work.
The drawback was that mud easily adhered to the square joints and their supporting metal fittings, leading to problems such as corrosion and rust.

The purpose of the present invention is to provide a pair of dozers without requiring special joints such as 3-way joints or complicating the piping structure, by a rational and simple improvement, in view of the above-mentioned conventional circumstances. The main point is that the cylinder can be connected in parallel to the pump.

The characteristic configuration of the present invention is that, in the piping of the above-mentioned earthmoving vehicle, the first and second dozer channels formed in the rotary joint are connected to the lower end surface of the rotary joint forming cylinder on the vehicle body side. A pair of pipes opened at the circumferential surface and separately connected to the bottom side chambers of both the fluid pressure cylinders are distributed and connected to the lower end surface opening and the circumferential surface opening of the first dozer flow path, and A pair of tubes, which are respectively connected to the rod side chambers, are distributed and connected to the lower end surface opening and the circumferential surface opening of the second dozer flow path.

In other words, the bottom side chambers or rod side chambers of both fluid pressure cylinders for lifting and lowering the dozer device are connected to the first flow path or the second flow path formed in the rotary joint.
Since the flow path can be directly connected to the two openings formed in each flow path by dividing and connecting the pipes, it is possible to connect the pipes directly to the two openings formed in each flow path. The number of piping structures can be reduced and the piping structure simplified, and the adhesion of earth and sand to the piping structure on the vehicle body side can also be reduced, thereby making it possible to prevent harmful effects such as corrosion and rusting. In addition, in order to open the first and second dozer flow paths at the lower end surface and circumferential surface of the rotary joint forming cylinder on the vehicle body side, the respective flow paths constructed from the lower end surface of the cylinder are Since the two openings can be formed by the conventionally known and extremely simple method of drilling branch holes from the circumferential surface of the cylindrical body, the overall improvement is simple and rational, and is improved in terms of cost and production and assembly efficiency. It has now been possible to provide piping for an earthmoving vehicle that is advantageous and has excellent durability.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in FIG. 1, a swivel base 2 is attached to a traveling vehicle body equipped with a crawler traveling device 1 through a rotary joint 3 so that it can be driven and rotated freely around a vertical axis P, and on the swivel base 2, A driving cabin 4 and a rear driving unit 5 are provided, and a backhoe device 6 is provided at the front end of the cabin 4, which can swing up and down as well as bend and extend.
is connected to the swivel base 2 so as to be able to swing left and right, and furthermore, a dozer device 8 is provided at the front end of the traveling vehicle body, which can be driven up and down by a pair of left and right hydraulic cylinders 7.
It is equipped with an earthwork vehicle that mainly performs ground excavation and earth removal work.

As shown in FIGS. 2 and 3, the drive structure of the dozer device 8 comprises a pair of left and right double-acting hydraulic cylinders 7 for lifting and lowering the dozer device, which are directly connected to an engine 9 provided on the swivel base 2 side. A hydraulic pump 10 is connected in parallel with an operating valve 11 through two oil passages 13a and 13b passing through channels 12a and 12b formed in the rotary joint 3, and by operating the operating valve 11. , one of the bottom side chamber 7a and rod side chamber 7b of both hydraulic cylinders 7 is connected to the pump oil passage 13a and the other to the tank oil passage 13b, or the operating oil is confined in both chambers 7a and 7b, and then the dozer device It is configured to carry out drive lifting, lowering and stopping operations of 8.

To form the dozer flow passages 12a and 12b in the rotary joint 3, two oil passages 13a and 13b from the operation valve 11, which become pump oil passages or tank oil passages by operating the operation valve 11, are connected to a rotating base. The rotary joint outer cylinder 3b connected to the second side is opened vertically in the inner wall of the outer cylinder 3b.
A rotary joint inner cylinder 3a, which is relatively rotatably fitted into the rotary joint inner cylinder 3a and connected to the traveling vehicle body side, has circumferential grooves a, which are in constant communication with the oil passages 13a and 13b, respectively.
b, and oil holes c and d that communicate with the circumferential grooves a and b separately and open at two locations on the lower end surface and lower circumferential surface of the inner cylinder 3a, respectively, and both hydraulic cylinders A pair of pipes 15a respectively connected to the bottom side chambers 7a of the hydraulic cylinders 7 are distributed and connected to the lower end surface opening and the peripheral surface opening of one oil hole c, and a pair of pipes 15a respectively connected to the rod side chambers 7b of both hydraulic cylinders 7 are connected separately. The pipes 15b are connected to the lower end surface opening and the peripheral surface opening of the other oil hole d. In other words, the dozer channels 12a and 12 formed in the rotary joint 3
b are opened at two locations on the lower end surface and the circumferential surface of the rotary joint inner periphery 3a on the traveling vehicle body side, so that the flow paths 12a, 12b, the bottom side chamber 7a of both hydraulic cylinders 7, and the rod side chamber 7b are opened. are structured so that they can be connected simply using the pipes 15a and 15b without using a special joint such as a three-way joint.

In addition, in configuring the rotary joint 3, when connecting the inner cylinder 3a to the swivel base 2 side and the outer cylinder 3b to the traveling vehicle body side, the dozer flow path 12
Both flow paths 12a and 12b are branched within the inner cylinder 3a or within the wall of the outer cylinder 3b so that each of the flow paths 12a and 12b is opened at the lower end surface and outer peripheral surface of the outer cylinder 3b. Various modifications can be made to the structure of the oil holes c and d for opening the oil holes 12a and 12b at the lower end surfaces and peripheral surfaces of the rotary joint forming cylinders 3a and 3b.

The piping for an earthwork vehicle according to the present invention can be applied to various types of earthwork vehicles equipped with a dozer device and a swivel base with a rotary joint.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the piping for the earthmoving vehicle according to the present invention, and FIG. 1 is an overall side view of the vehicle, FIG. 2 is a partially omitted plan view taken from the - line in FIG. 1, and FIG. The figure is a schematic view showing the drive structure of the dozer device, and FIG. 4 is a partially omitted plan view of the main part showing a conventional example. 2...Swivel base, 3...Rotary joint,
3a... Cylindrical body, 7... Cylinder, 7a... Bottom side chamber, 7b... Rod side chamber, 8... Dozer device,
10... Bump, 12a, 12b... Channel, 15
a, 15b...tube.

Claims (1)

[Scope of utility model registration request] A dozer device 8 is attached to a vehicle body equipped with a swivel base 2, and the dozer device 8 is supplied to a pump 10 provided on the swivel base 2 via a rotary joint 3 interposed between the swivel base 2 and the vehicle body. Piping for an earthwork vehicle in which a pair of left and right lifting fluid pressure cylinders 7 are connected in parallel, and the rotary joint 3
The first and second dozer channels 12a, 1 formed in
2b are opened at the lower end surface and peripheral surface of the rotary joint 3 forming cylinder 3a on the vehicle body side, and the bottom side chambers 7a of both the fluid pressure cylinders 7 are opened.
A pair of tubes 15a, each connected to the rod side chamber 7b of both body pressure cylinders 7, are divided and connected to the lower end surface opening and the peripheral surface opening of the first dozer flow path 12a, and a pair of tubes 15a, each separately connected to the rod side chamber 7b of the body pressure cylinder 7, Piping for an earthwork vehicle, characterized in that the pipes 15b are distributed and connected to the lower end surface opening and the peripheral surface opening of the second dozer flow path 12b.