JPH1030775A - Swivel joint device having built-in valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost by performing the function of a safety valve, or the like with a swivel joint device without providing any safety valve, or the like in a hydraulic circuit on the upstream side of the swivel joint device of a working machine having a turning body such as a hydraulic shovel to dispense with a hydraulic piping or a hydraulic joint required for installation of the safety valve, etc. SOLUTION: This swivel joint device 5 is provided with a shaft part 3 to be fixed to a traveling body 2 of a working machine having a turning body 1, and a body which is locked to the turning body 1 and rotatably mounted thereon. The set pressure to control the hydraulic circuit is adjusted by providing a valve 6 such as a safety valve, etc., to control the hydraulic circuit in the shaft part and providing a pressure adjustment screw 7 to adjust the set pressure to control the hydraulic circuit on an outer circumference of the shaft part 3 in an assembled condition to the working machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swivel joint device for a working machine such as a hydraulic shovel having a revolving unit and a traveling unit, which is arranged at the revolving center of the revolving unit.

[0002]

2. Description of the Related Art In a conventional swivel joint device of a working machine such as a hydraulic excavator, the swivel joint device is disposed at the center of rotation of the revolving structure, in which the revolving structure can freely rotate with respect to a traveling body. A valve such as a safety valve is installed before and after to control the hydraulic circuit. However, in a machine such as a hydraulic shovel that allows the swinging body to swing with a small radius, the space on the swinging body is narrow, and it is difficult to secure the installation space. Often.

[0003]

A conventional swivel joint device for a working machine such as a hydraulic excavator is characterized in that the revolving body can freely swing with respect to a traveling body, and a safety valve or the like is provided in a circuit on the upstream side of the swivel joint device. When installing a safety valve etc. in the circuit downstream of the swivel joint device, install it on the traveling body.However, in any case, it is difficult to secure the installation place and the hydraulic circuit is The longer length increases the cost of manufacturing hydraulic piping and hydraulic couplings.

[0004]

In order to achieve the above object, a swivel joint device for a working machine having a revolving body such as a hydraulic shovel according to the present invention comprises: a shaft fixed to a traveling body of the working machine; It is composed of a body that is locked to the revolving body of the machine and rotatably fits on the shaft part. By incorporating a valve such as a safety valve inside the shaft part, and providing a set pressure adjusting screw on the shaft part The set pressure can be adjusted while being assembled to the machine, so that a valve such as a safety valve of a hydraulic circuit upstream or downstream of the swivel joint device can be omitted, and hydraulic piping and hydraulic joints can be reduced.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a swivel joint device 5 of a working machine having a revolving unit 1 such as a hydraulic shovel constructed as described above, a safety valve and the like are provided inside a lower portion of a shaft 3 fixed to a traveling unit 2 of the working machine. The set pressure adjusting screw 7 is provided on the outer periphery of the lower portion of the shaft portion 3 so that the set pressure of the valve 6 such as a safety valve in the hydraulic circuit can be adjusted. As a result, the safety valve 29 of the hydraulic circuit on the upstream or downstream side of the swivel joint device 5 can be omitted, and when a sudden high pressure is generated on the downstream side of the swivel joint device 5, the safety valve 29 is installed on the upstream side. The valve 6 such as a safety valve can operate faster because it is closer to the position where the high pressure is generated.

Next, a detailed embodiment of the swivel joint device 5 of the present invention having the above-described structure will be described with reference to a longitudinal sectional view of FIG. FIG. 2 is a longitudinal sectional view showing one embodiment of a swivel joint device of a shovel. Referring to FIG. 2, a shaft portion 3 and a body 4 of a swivel joint device 5 according to the present invention include:
An oil passage 17 for supplying high-pressure oil to the right traveling motor 23 at the upper part
a, 17b and return oil passage 18 from right traveling motor 23
a, 18b and oil paths 19a, 19b for supplying high-pressure oil to the left traveling motor 24 and oil paths 20a, 20b returning from the left traveling motor 24. Further, oil passages 21a and 21 for supplying high-pressure oil to the discharge plate actuator 15 are provided.
b and the return oil passage 22 from the earth removal plate actuator 15
a, 22b, but a valve 6 is provided below the shaft 3 of the present invention.
And the valve 6 is connected to the oil passage 21 via the oil passages 21c and 22c.
a, 21b and 22a, 22b.

Therefore, when a high pressure exceeding the set pressure is generated in the oil passages 21a and 21b, the force for pushing the valve 6 to the left becomes larger than the reaction force of the spring 9, and the valve 6 moves to the left. The high-pressure oil passes through the oil passages 21a, 21c and passes through the oil passages 22c, 22a to return to the tank 13 of the hydraulic pressure source. When the pressure in the oil passage 21c becomes equal to or lower than the set pressure, the spring 9 When the force exceeds the hydraulic pressure, the valve 6 is moved to the right and returns to the position shown in FIG. 1, the space between the oil passages 21c and 22c is closed, and the valve 6 is opened and closed at the set pressure. A balance will be achieved.

Conversely, when a high pressure higher than the pressure set in the oil passages 22a and 22b is generated, the high pressure in the oil passage 22c is transmitted to the inside of the valve 6 through the oil passage 38 so that the valve 6 is moved to the right. And the valve 6 is kept closed. A hydraulic circuit diagram for explaining the operation of the safety valve 16 in the hydraulic circuit is as shown in FIG.

Next, the swivel joint device 5 of the present invention
3 and FIG. 4 show the safety valve 1 for the swivel joint device 5.
6 is compared with the case where the safety valve 29 is separately provided. As shown in FIG. 3, the swivel joint device 5 of the present invention has a high pressure higher than the set pressure near the discharge plate actuator 15 as shown in FIG. Is generated, the length of the pipe between the discharge plate actuator 15 and the swivel joint device 5 is changed to the length shown in FIG.
Since the safety valve 29 can be shortened as compared with the case where the safety valve 29 is installed in the vicinity of the directional control valve 14, the operation of the safety valve 16 is accelerated, so that hydraulic equipment in the hydraulic circuit is more effectively protected from overpressure. can do.

As described above, the swivel joint device 5
When the safety valve 16 is built in the swivel joint device 5
It is effective to control the hydraulic circuit on the downstream side of
FIG. 5 is a cross-sectional view showing a case where the valve 6 is built in the lower part of the shaft 3 as the first embodiment of the present invention, and an auxiliary shaft 33 is assembled in the lower part of the shaft 3 as the second embodiment. Valve 6 inside
FIG. 6 is a cross-sectional view showing the case where the valve 6 is incorporated. To explain the advantages and disadvantages of both, when the valve 6 is incorporated below the shaft portion 3 of the first embodiment, the machining surface can be reduced, which is advantageous in terms of manufacturing cost. However, since the outer cylinder 42 is provided as shown in FIG. 5, the valve 6 and the like are incorporated into the shaft 3 after assembly inside the outer cylinder 42. On the other hand, when assembling the auxiliary shaft 33 below the shaft portion 3 and incorporating the valve 6 therein, machining of the end face of the lower portion of the shaft portion 3 and machining of the upper surface of the auxiliary shaft 33 are required.
As shown in the figure, the auxiliary shaft 33 having a size suitable for the flow rate can be selected, so that the valve 6 capable of controlling a large flow rate can be built in, and the valve 6 and the like are assembled on the auxiliary shaft 33 machined as a single unit. Since the auxiliary shaft 33 can be attached to the shaft portion 3, a complicated valve can be built in.

As described above, the swivel joint device 5 of the present invention uses the first embodiment and the second embodiment properly according to the above-mentioned advantages and disadvantages. Even in the case of the second embodiment in which the auxiliary shaft 33 is mounted, there is a space for adjusting the pressure adjusting screw 39 below the shaft portion 3 at the center of the body 2, so that it is mounted on the hydraulic excavator. The set pressure of the valve 6 can be adjusted.

[0012]

The swivel joint device according to the present invention is provided with a valve mechanism such as a safety valve at the lower part of the shaft portion to prevent the occurrence of abnormal high pressure downstream of the swivel joint device of the hydraulic circuit. Compared to the case where a valve such as a safety valve is installed upstream of the joint device, it is possible to effectively control the pressure of the hydraulic circuit, and it is possible to omit the hydraulic piping and the hydraulic coupling. Manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a swivel joint device of the present invention.

FIG. 2 is a longitudinal sectional view related to the swivel joint device of the present invention.

FIG. 3 is a hydraulic circuit diagram relating to a swivel joint device and an actuator of a discharge plate according to an embodiment of the present invention.

FIG. 4 is a hydraulic circuit diagram relating to a swivel joint device and an actuator of a discharge plate according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a safety valve below a shaft portion of the swivel joint device according to the first embodiment of the present invention.

FIG. 6 is a diagram of a mounting surface of an auxiliary shaft below a shaft portion of a swivel joint device according to a second embodiment of the present invention.

FIG. 7 is a perspective view illustrating a state in which a swivel joint device according to the embodiment of the present invention is mounted on a traveling body of a hydraulic shovel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Revolving superstructure 2 Traveling body 3 Shaft 4 Body 5 Swivel joint device 6 Valve 7 Pressure adjusting screw 8 Plug 9 Spring 10 Plug 11 Washer 12 Plug 13 Hydraulic power source 14 Direction switching valve 15 Actuator for earth removal plate 16 Safety valve 17a Oil passage 17b oil line 18a oil line 18b oil line 19a oil line 19b oil line 20a oil line 20b oil line 21a oil line 21b oil line 21c oil line 22a oil line 22b oil line 22c oil line 23 running motor 24 running motor 24 safety valve 26 direction switching Valve 27 Direction switching valve 28 Safety valve 29 Safety valve 30 Crossover safety valve 31 Crossover safety valve 32 Safety valve 33 Auxiliary shaft 34 Fastening bolt 35 O-ring 36 Plug 37 Plug 38 Oil path 39 Pressure adjusting screw 40 Spring 41 Washer 42 Outer cylinder 43 Seal

Claims (2)

[Claims] 1. A swivel joint device having a shaft fixed to a traveling body of a work machine having a revolving body and a body locked to the revolving body and rotatably fitted to the shaft. A swivel joint device comprising a valve such as a safety valve for controlling a hydraulic circuit inside the section. 2. The swivel joint device according to claim 1, wherein a pressure adjusting screw for adjusting a set pressure of a valve of the shaft portion is provided on an outer periphery of the shaft portion so that the set pressure can be adjusted in a state where the swivel joint device is assembled to a work machine. Swivel joint device.