JPS5921285Y2 - Automatic degassing valve in hydraulic system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a valve for automatically removing gas such as air from a hydraulic system such as a hydraulic cylinder.

Generally, an air bleed valve is installed to bleed out any air remaining in the hydraulic cylinder.

If air remains in the hydraulic cylinder, conventional methods open the air bleed valve and send oil into the cylinder to expel the air.
After the air was released and the air release valve was closed, the hydraulic cylinder started normal operation.

When there are a large number of hydraulic cylinders, it takes manpower and time to open each air bleed valve, send oil and bleed air, and operate the large number of hydraulic cylinders.

The present invention aims to eliminate the above-mentioned drawbacks and provide an automatic gas vent valve that is compact, inexpensive, causes few troubles, and is highly reliable.Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. do.

Reference numeral 1 denotes a main body, which has a gas port 2 communicating with a small air vent of a hydraulic cylinder, a gas outlet 3 for discharging air to the outside air, and a gas passage 4 communicating the gas port 2 and the gas outlet 3. .

A free piston 5 is installed in the gas passage 4 so as to be able to slide in an airtight manner.
A valve 6 is installed in the free piston 5.

A check valve 7 for preventing gas backflow is provided at the gas outlet 3.

The free piston 5 is pressed downward by a spring 9 interposed between its upper end surface and the lower end surface of a plug 8 screwed into the main body 1.

Further, the valve 6 is operated by a spring 10 which is weaker than the spring 9, and the valve seat 1 is
It is being pushed towards 1.

When pressure oil is introduced into the hydraulic cylinder, the air remaining in the hydraulic cylinder passes through the small air vent hole and enters the main body 1 from the gas port 2, forming the valve seat 1 on the seating surface of 11 as shown by the arrow. The gas outlet passes through the groove 12 provided in the groove 12, the through hole 16 provided in the hooks 1 to 5, and the through hole 15 provided in the main body 1, and passes through the groove 18 provided in the valve seat 17 of the check valve 7 for preventing backflow. 3 is discharged to the outside air.

When the air in the hydraulic cylinder disappears and the pressure oil reaches the groove 12 of the valve seat 11, the viscous resistance of the oil is large, so the valve 6 is pushed upward against the spring 10, and becomes free as shown by the two-dot chain line in the figure. It is seated on a valve seat 13 formed on the piston 5 and blocks the flow of pressure oil.

When the pressure of the pressurized oil increases, the free piston 5 is raised against the spring 9, and the upper edge 14 of the free piston 5 blocks the through hole 15.

When the pressure inside the hydraulic cylinder becomes negative, the check valve 7 for preventing backflow is seated on the valve seat 19 to prevent air from flowing into the cylinder.

Further, when the free piston 5 or the valve 6 cannot be moved for some reason, the plug 20 is removed and air is extracted from there.

As specifically explained in the embodiments above, the present invention has the following features:
It is equipped with a valve that allows gas with low viscous resistance to pass through, but blocks the passage of liquid with high viscous resistance, so it detects when gas in a hydraulic system such as a hydraulic cylinder is released and automatically closes the liquid bath. Since the air can be prevented from coming out, there is almost no need for time and labor for removing air as in the conventional case.

In the present invention, if dirt gets caught in the seat of the valve, the free piston shuts off the gas passage when the pressure difference between the gas inlet and the gas outlet exceeds a certain value. The hydraulic system can be operated safely and reliably.

Another advantage is that when the pressure inside the hydraulic system becomes negative, the check valve prevents air, etc. from flowing into the hydraulic system, ensuring safe and reliable operation of the hydraulic system. .

[Brief explanation of the drawing]

The drawing is a sectional view showing one embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] A main body that has a gas inlet, a gas outlet, and a gas passage that communicates these with the hydraulic system, and is installed in the gas passage of the main body, and when the pressure difference between the gas inlet and the gas outlet exceeds a certain value. , a free piston that blocks the gas passage, a valve built into the free piston that allows gas with low viscous resistance to pass through and blocks passage of liquid with high viscous resistance, and a gas backflow prevention device provided at the gas outlet of the main body. An automatic gas vent valve for a hydraulic system, characterized by being equipped with a check valve.