JPH06299568A - Operation circuit for tilt angle dozer device - Google Patents

Abstract

PURPOSE:To simplify pipings and improve operability by providing a tilt angle switching valve on a lower travelling body, connecting a tilt cylinder and an angle cylinder parallelly to the tilt angle switching valve, and operating a tilt angle control valve mounted to an upper rotating body. CONSTITUTION:A tilt angle switching valve 31 is mounted to a lower travelling body 1, and a tilt cylinder 6 and an angle cylinder 7 are connected parallelly to the valve 31, and both the cylinders 6, 7 are connected to an upper rotating body 9 through a control valve 33 for tilt and angle and a swivel joint 32. And a tilt action or an angle action is selected by the control valve 33. As a result, pipings can be simplified and operability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation circuit of a tilt angle dozer device equipped on an upper-slewing construction machine.

[0002]

2. Description of the Related Art FIG. 4 is a cutaway side view of a hydraulic excavator equipped with a tilt angle dozer device. In the figure, 1 is a lower traveling body, 2 is a lower frame of the lower traveling body 1, 3 is an arm for a dozer, 4 is a blade, 5 is a dozer cylinder, 6 is a tilt cylinder, 7 is an angle cylinder, and 8L and 8R are left and right. Traveling motor, 9 is an upper swing body,
Reference numeral 10 is a swing motor, 11 is a swivel joint, and 12 is a work attachment mounted on the front part of the upper swing body 9. FIG. 5 is a perspective view showing the periphery of the blade 4 in FIG. In the figure, 13 is a spherical joint that connects the arm 3 and the blade 4. Arrows a and b indicate the tilt operation direction of the blade 4, and arrows c and d indicate the angle operation direction of the blade 4.

Next, FIG. 6 is a main part circuit diagram showing an operation circuit of a tilt angle dozer device of the prior art. In the figure, 14L and 14R are switching valves for traveling, which control the left and right traveling motors 8L and 8R, respectively, 15, 16, 17, 18
Is a pilot switching valve for controlling various hydraulic actuators equipped on the hydraulic excavator, and 19, 20, 21 are control valves for dozer, tilt, and angle, respectively.
22 is a straight-ahead travel valve, and 23, 24 and 25 are the first and second
Second and third pumps, 26 is a pilot pump, 27 is an oil tank, 28L and 28R are 1s for travel motors 8L and 8R
A second-speed switching valve, 29 is an electromagnetic switching valve provided in the traveling second-speed pilot pressure circuit, and 30 is a first-speed / second-speed switching switch.

In a hydraulic excavator having a tilt angle dozer device as shown in FIGS. 4 and 5, the lower traveling body 1 is used.
An arm 3 is provided so as to be vertically swingable by a dozer cylinder 5, and a blade 4 is attached to a tip end portion of the arm (3) so as to be tiltably swingable by a tilt cylinder 6. See also FIG.
As shown in FIG. 2, in the conventional technique, when operating the dozer cylinder 5, tilt cylinder 6, and angle cylinder 7, the control valves (19, 20, 21) for dozer, tilt, and angle are operated. The pressure oil from the third pump 25 is supplied to each cylinder through the control valve and their supply / discharge circuits. Further, when it is desired to travel the hydraulic excavator at the high speed of the second speed, turning on the first-speed / second speed switching switch 30 adjusts the motor capacity of the travel motors 8L and 8R, so that the second speed of the travel can be performed. .

[0005]

Among the hydraulic excavators, particularly small excavators, the miniaturization and miniaturization thereof are being promoted, and the piping capacity of the swivel joint is also limited. Therefore, it was difficult to separately pass the supply / discharge circuits leading to the dozer, tilt, and angle cylinders through the swivel joint. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide an operating circuit that can effectively operate the tilt, angle, and dozer cylinders when the hydraulic excavator is traveling in the first speed, the second speed, and when the traveling is stopped.

[0006]

In the operation circuit of the tilt angle dozer device of the present invention, a tilt angle switching valve is provided on the lower traveling body, and the tilt angle switching valve and the tilt angle switching valve arranged on the upper revolving structure are used. The control valve is communicated with a swivel joint, and the tilt angle and the angle cylinder are connected in parallel to the tilt angle switching valve. In the lower traveling body,
A selector valve that can selectively switch between the tilt cylinder operation circuit and the angle cylinder operation circuit is provided, and the selector valve and the tilt angle control valve arranged on the upper swing body are connected via a swivel joint.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a circuit diagram of an essential part showing an operation circuit of a tilt angle dozer device according to claim 1 of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. Reference numeral 31 is a tilt angle switching valve, 32 is a swivel joint, and 33 is a tilt angle control valve. FIG. 2 shows the tilt angle switching valve 31.
It is a principal part block diagram which shows the switching operation structure of. In the figure,
Reference numeral 34 is a slewing bearing interposed between the lower traveling body 1 ′ and the upper slewing body 9 ′, 35 is an outer joint of the swivel joint 32, 36 is an inner joint, and 37 is an inner joint 36. An axial center through hole, 38 is a tilt-angle switching operation lever provided on the upper swing body 9 ′,
Reference numeral 39 is a push-pull cable that is inserted into the axial center through hole 37 of the internal joint 36 and connects the lower end of the operation lever 38 and the spool end of the tilt angle switching valve 31.

Next, the configuration of the operating circuit according to claim 1 of the present invention will be described with reference to FIGS. Manually operated tilt angle switching valve 31 on the undercarriage 1'of the hydraulic excavator
The tilt angle switching valve 31 and the tilt angle control valve 33 arranged on the upper swing body 9 ′ are communicated with each other through the swivel joint 32, and the tilt cylinder is connected to the tilt angle switching valve 31. 6 and the angle cylinder 7 are connected in parallel.

Next, the operation of the operating circuit according to claim 1 of the present invention will be described. The dozer cylinder 5 can be controlled as required by operating the dozer control valve 19. Next, the control of the tilt cylinder 6 and the angle cylinder 7 will be described. First, the case of operating the angle cylinder 7 will be described.
When the operation lever 38 shown in FIG. 2 is in the position of E, the tilt angle switching valve 31 (same for the tilt angle switching valve 31 shown in FIG. 1) is in the angle opening oil passage position. Since the tilt angle control valve 33 communicates with the angle cylinder 7 via the tilt position of the tilt angle switching valve 31, the tilt cylinder control valve 33 can be operated to operate the angle cylinder 7. Next, the case of operating the tilt cylinder 6 will be described. Operation lever 3 shown in FIG.
When 8 is switched from the E position to the F position, the tilt angle switching valve 31 switches from the G position to the tilt open oil passage position C. The tilt angle control valve 33 moves the tilt cylinder 6 through the tilt position of the tilt angle switching valve 31.
The tilt cylinder 6 can be operated by operating the tilt angle control valve 33. Therefore, the dozer cylinder 5 can be operated as required at any time, and the traveling first speed, second speed,
The tilt cylinder 6 or the angle cylinder 7 can be operated with or without the dozer cylinder 5 regardless of non-traveling. That is, in the operation circuit of the present invention, regardless of whether the hydraulic excavator is traveling or not traveling,
Since only the tilt operation and the angle operation are selected and operated from the dozer operation, the tilt operation and the angle operation,
The tilt angle dozer work, which does not require the simultaneous operation of tilt and angle, is fully accomplished, and the number of cylinder operating circuits passing through the swivel joint can be reduced by one circuit. In this embodiment, the manually operated operation lever 38 is provided on the upper swing body 9'and the tilt angle switching valve 31 is switched via the push-pull cable 39, but the invention is not limited to this and the push / pull is manually performed. The tilt angle switching valve may be arranged on the lower traveling body 1 ', and the driver may get off the tilt angle switching valve and switch it. Although not shown, a tilt angle switching valve of an electromagnetic operation type or a pilot operation type may be provided by passing an electric wiring or a pilot oil passage through a swivel joint.

Next, FIG. 3 is a main part circuit diagram showing an operation circuit according to claim 2 of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as the operation circuit of claim 1. In the operating circuit according to claim 2, selector valves 40a and 40b capable of selectively switching the tilt cylinder (6) operating circuit and the angle cylinder (7) operating circuit are provided on the lower traveling body (1 '), and the selector valve is provided. 40
a and 40b and a tilt angle control valve 33 arranged on the upper swing body (9 ') are connected to each other via a swivel joint 32. Thereby, when the selector valves 40a and 40b are set to the switching positions as shown in FIG. 3 and the operation circuit of the angle cylinder (7) is selected, the tilt valve control valve 33 can be operated to perform the angle operation. . When the selector valves 40a and 40b are switched and the tilt cylinder (6) operating circuit is selected, the tilt operation can be performed by operating the tilt angle control valve 33. The operation and function of the operating circuit of claim 2 are the same as those of the operating circuit of claim 1.

[0011]

The small-sized shovel of the prior art is limited in size and weight, and it is difficult to separately pass the supply / discharge circuit leading to each of the tilting cylinder and the angle cylinder through the swivel joint. However, in the operation circuit of the tilt angle dozer device of the present invention, the tilt angle switching valve or the selector valve is used for the tilt angle switching valve or the selector valve for the tilt angle switching valve in which the selector valve is arranged in the lower traveling body of the hydraulic excavator. The tilt cylinder and angle cylinder are connected in parallel. Thus, the tilt cylinder or the angle cylinder can be operated by switching the tilt angle switching valve or the selector valve and operating the chimeto angle control valve. That is, in the operating circuit of the present invention, regardless of whether the hydraulic excavator is running or not running, only the tilt operation and the angle operation are selectively operated among the dozer operation, the tilt operation, and the angle operation. The tilt angle dozer work, which does not require simultaneous operation, can be fully accomplished, and the number of cylinder operating circuits passing through the swivel joint can be reduced by one circuit.

[Brief description of drawings]

FIG. 1 is a main part circuit diagram showing an operation circuit of a tilt angle dozer device according to claim 1 of the present invention.

FIG. 2 is a main part configuration diagram showing a switching operation structure of a tilt angle switching valve in FIG.

FIG. 3 is a main part circuit diagram showing an operation circuit according to claim 2 of the present invention.

FIG. 4 is a cutaway side view of a hydraulic excavator equipped with a tilt angle dozer device.

FIG. 5 is a perspective view showing the periphery of the blade in FIG.

FIG. 6 is a circuit diagram of a main part showing an operation circuit of a tilt angle dozer device according to a conventional technique.

[Explanation of symbols]

 1 Lower Traveling Body 4 Blade 5 Dozer Cylinder 6 Tilt Cylinder 7 Angle Cylinder 8L, 8R Traveling Motor 11, 32 Swivel Joint 19 Dozer Control Valve 28L, 28R 1-2 Speed Switching Valve 31 Tilt Angle Switching Valve 33 Tilt Angle Control Valve 40a, 40b Selector valve

Claims (2)

[Claims] 1. A lower traveling structure is provided with a dozer arm that can be vertically moved by a dozer cylinder, and a blade is attached to a front end portion of the dozer arm so that the tilt cylinder can perform a tilt operation and the angle cylinder can perform an angle operation. In the upper revolving construction machine, a tilt angle switching valve is provided on the lower traveling body, and the tilt angle switching valve and the tilt angle control valve disposed on the upper revolving body are communicated via a swivel joint, and An operating circuit for a tilt angle dozer device, wherein a tilt cylinder and an angle cylinder are connected in parallel to the tilt angle switching valve. 2. A lower traveling structure is provided with a dozer arm that can be vertically moved by a dozer cylinder, and a blade is attached to a front end portion of the dozer arm so that the tilt cylinder can perform a tilt operation and the angle cylinder can perform an angle operation. In an upper swing construction machine, a selector valve that can selectively switch between a tilt cylinder operating circuit and an angle cylinder operating circuit is provided in the lower traveling structure, and the selector valve and the tilt angle control valve arranged in the upper rotating structure are provided. An operating circuit for a tilt angle dozer device, characterized in that the two are communicated via a swivel joint.