JPH0447221Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a blade lifting device.

[Prior art and technical issues to be solved] The blades of recent snowplows are equipped with two independent hoist cylinders on the left and right sides, allowing them to perform not only simple lifting and lowering operations but also tilting operations. It is often designed as such. For example, when passing through a bridge joint, a snowplow like this is used while keeping the left end of the blade in contact with the ground.
This is because by raising the blade slightly above the road, snow removal work can be carried out without the blade getting caught in the protruding joint, which is very convenient.

However, with such snowplows, the left and right hoist cylinders expand and contract independently, so
A great deal of skill was required to avoid problems caused by the difference in the amount of expansion and contraction of both cylinders when the blade was raised and lowered. especially,
Truck graders, in which the blade tends to be located near the center of the snowplow, behind the driver's seat, are extremely difficult to operate.

This invention was developed in response to the above-mentioned problems with conventional blade hoist devices, and aims to facilitate the lifting and lowering operation of the blades, that is, to easily synchronize the expansion and contraction of the left and right hoist cylinders. The technical challenge is to make this possible.

[Means for Solving the Problems] In the present invention, left and right hoist cylinders 3 and 4 are provided, a fluid feeding mechanism for pressure feeding fluid is provided thereto, and a fluid feeding mechanism for pressure feeding fluid to the left hoist cylinder 3 is provided. a first direction switching solenoid valve 7 that switches the direction;
A second direction switching solenoid valve 8 that switches the direction of pressure feeding of fluid to the right hoist cylinder 4 is adopted, and these first direction switching solenoid valve 7 and second direction switching solenoid valve 8
The operation of the tilting device 5 and the operating device 6 can be independently controlled, and
The above problem is solved by adding a lifting operation device 9 that controls the operation of the directional solenoid valve 7 and the second directional solenoid valve 8 so that they are simultaneously switched in the same direction. did.

[Example] Hereinafter, the present invention will be explained in more detail based on the illustrated example.

FIG. 3 is a hydraulic circuit diagram of the left and right hoist cylinders 3 and 4 that extend and contract using fluid pressure. In the figure, 14 and 15 are check valves, 7 and 8 are directional switching solenoid valves, and 16 is a solenoid control relief valve.

FIG. 6 shows a conventional control switch. In the figure, the monolever switch 6 operates the expansion and contraction of the right hoist cylinder 4, and the monolever switch 5 operates the expansion and contraction of the left hoist cylinder 3. be. Further, 17 is a monolever switch for operating the blade reversal. In addition,
FIG. 4 is an electrical wiring diagram showing the connection between the monolever switch and the directional solenoid valve in the conventional product.

In the conventional products shown in these figures, the blade is raised and lowered by a mono lever switch 5.
It is necessary to simultaneously operate the two hoist cylinders 3 and 4 and extend and retract the two hoist cylinders 3 and 4. However, this operation is easier said than done.

On the other hand, in this embodiment, as shown in FIG. 7, one monolever switch 9 is newly added. Operating only one monolever switch 9 has the same effect as operating monolever switches 5 and 6 at the same time. That is, as shown in FIG. 7, monolever switch 9 is connected to both monolever switches 5 and 6. In addition, the configuration other than this is
No different from conventional products. That is, as shown in FIGS. 1 and 2, the blade 2 is disposed at the lower center of the chassis 1 via the left and right hoist cylinders 3 and 4, and as both cylinders expand and contract, the blade moves up and down and tilts. do. In addition, the left and right hoist cylinders 3 and 4 have check valves 14 and 15 and directional switching valves 7 and 8.
The fluid whose supply pressure is adjusted by the control relief valve 16 is sent from the fluid pressure pump via the control relief valve 16. The cylinders 3 and 4 expand and contract by operating the directional control valves 7 and 8.

When the monolever 9 is operated, the left and right hoist cylinders 3 and 4 are synchronously expanded and contracted by the same amount, and the blade 2 is raised and lowered without difficulty. Further, when tilting the blade 2, it is sufficient to operate either the monolever switch 5 or 6 to extend or contract only one of the left and right hoist cylinders 3 and 4. For example, when avoiding a joint part of a bridge, the right hoist cylinder 4 may be retracted by a slight amount by operating the monolever switch 6, so that the right end of the blade is lifted 2 to 3 cm from the road surface. After this, operate the monolever switch 9 to equalize the fluid pressure in both cylinders 3 and 4, and once again align the height of the right edge of the blade with the height of the left edge of the blade. From then on, the edge will remain horizontal. The blade 2 can be raised and lowered.

It should be noted that the monolever switches 5, 6, and 9 in this embodiment correspond to the left tilting operation device, the right tilting operation device, and the lifting and lowering operation device, respectively, as referred to in the claims of the utility model registration. However, the left tilting operation device, right tilting operation device within the scope of the utility model registration claim,
The lift operation device is not limited to a monolever switch, and other types of switches may be used.

[Effects of the present invention] As described above, the blade hoist device of the present invention simplifies blade operation and enables even inexperienced snow removal workers to operate the blade reliably, and has high industrial utility value. .

[Brief explanation of the drawing]

FIG. 1 is an overall side view of a snowplow to which a track grader is attached, FIG. 2 is an explanatory diagram of the raising and lowering movement of the grader blade, and FIG. 3 is a hydraulic circuit diagram of the left and right hoist cylinders of the blade. Further, FIG. 4 is an electrical wiring diagram showing the connection between a conventional control switch and a directional control valve, and FIG. 5 is an electrical wiring diagram of an embodiment. Furthermore, FIG. 6 is an external view of a conventional control switch, and FIG. 7 is an example. 1... Chassis, 2... Blade, 3... Cylinder for left hoist, 4... Cylinder for right hoist.

Claims (1)

[Claims for Utility Model Registration] A left hoist cylinder 3 connected to the lower part of the chassis 1 and the left side of the rear surface of the blade 2, a right hoist cylinder 4 connected to the lower part of the chassis 1 and the right side of the rear surface of the blade 2, and a left hoist. a first direction switching solenoid valve 7 that expands and contracts the cylinder 3 by switching the direction of pumping fluid to the cylinder 3 for the left hoist; , a second direction switching solenoid valve 8 that expands and contracts the cylinder 4 by switching the direction of pumping fluid to the right hoist cylinder 4; and a left tilting operation device 5 that controls the operation of the first direction switching solenoid valve 7. , a right tilting operator 6 that controls the operation of the second directional solenoid valve 8, a first directional solenoid valve 7, and a second directional solenoid valve 8.
1. A blade hoist device for a truck grader, characterized in that the blade hoist device is comprised of a lifting operation device 9 that controls the operation of the blade hoist so as to simultaneously switch the blade hoists in the same direction.