JPH0543281Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a piston-type accumulator that facilitates the detection of gas leaks.

[Conventional technology]

Conventionally, as shown in Japanese Patent Publication No. 54-33366, the inner chamber of a cylinder is divided into an oil chamber and a gas chamber by a floating piston that moves freely within the cylinder, and this gas chamber is filled with, for example, nitrogen gas. An accumulator in which pressure oil is introduced into the oil chamber from a hydraulic circuit is known as a so-called piston type accumulator.

[Problem that the invention attempts to solve]

By the way, due to the nature of the gas in the accumulator, a small amount of leakage cannot be avoided, and if the amount of leakage exceeds a certain limit, the pressure accumulating function required in the hydraulic circuit in which this accumulator is used cannot be satisfied.

The basic method to detect this gas leak is to remove the hydraulic pressure from the accumulator, expand the gas to its full cylinder capacity, and compare the pressure in this state with the pressure when the gas was initially charged. The hydraulic circuit must be shut down. Furthermore, if gas leaks and the amount of gas in the accumulator decreases, the piston position under the same oil pressure (which is equal to the gas pressure) will shift toward the gas side, so there is no way to detect gas leaks based on changes in the piston position. However, when the pointer indicating the piston position is pulled out to the outside of the cylinder, the chances of gas leakage increase, which is undesirable from a structural standpoint. Furthermore, when the amount of gas in the accumulator decreases, the volume in the adjacent oil chamber increases, and the amount of oil sent by the pump increases, so the operating time of the pump to reach a constant pressure or the degree of drop in the level of the oil storage tank, etc. A method of detecting gas leaks by capturing them has also been adopted, but this method has the drawback of poor detection accuracy.

This invention was made to solve these problems, and aims to provide a piston-type accumulator with a simple configuration and a means for accurately detecting gas leaks even when the hydraulic circuit is in operation. .

[Means for solving the problem] The piston type accumulator according to this invention is
The outer surface of the gas chamber, including the seal, is covered with a stretchable hood.

[Effect]

The hood according to this invention is inflated by the leaked gas when a leak occurs from the seal part of the gas chamber of the accumulator, and the presence or absence of a leak or the amount of leakage can be determined by the presence or absence or size of this bulge.

〔Example〕

The drawing shows an embodiment of this invention. In the drawing, an accumulator 1 is made up of a cylindrical cylinder 2 with both ends closed and a floating piston 3. The piston 3 has an oil chamber 4 inside the cylinder. It is fitted into the cylinder so that it can be freely moved within the cylinder while being divided into a gas chamber 5. Pressure oil is introduced into the oil chamber 4 through a conduit 6 connected to a hydraulic circuit (not shown), while the gas chamber 5 is filled with, for example, nitrogen gas. Note that a piston ring (not shown) is attached to the outer periphery of the piston 3 to provide a seal between the chambers 4 and 5.

Further, on the gas chamber 5 side, sealing members 9 and 10 are provided at the joints of the plug 7 and end metal 8, respectively, to prevent gas leakage. Reference numeral 11 designates an elastic hood provided to cover the outer periphery of the accumulator including these seal portions, and is tightly attached to the cylinder 2 through end tightening portions 11a.

In the above configuration, in the unlikely event that the seal portion 9,
If a leak occurs from 10, the leaked gas will enter the hood 11, but since the hood 11 has elasticity, it will remain in the hood in an inflated state. Therefore, if the hood is brought into close contact with the accumulator at the beginning, gas leakage can be easily detected based on the presence or absence of a bulge, and the amount of gas leakage can also be determined based on the size of the bulge. Generally, in gas chamber 5
High-pressure gas of about 100 to 200 Kgf/cm ² is sealed, for example ^, 1 c.c.
Even if there is a leak, the inside of the hood is at almost atmospheric pressure, and approximately
Detection accuracy is high because it expands by 200c.c.

In the above example, an example was shown in which the inspection was performed based on the bulge in the hood, but the leaked gas inside the hood may be guided into another container for quantitative measurement, or it may be introduced into a container filled with liquid and checked at a constant level using a float switch, etc. A method may be used in which an alarm is issued when the amount is exceeded.

[Effect of idea]

As described above, according to this invention, gas leakage from the accumulator can be detected using the hood that covers the outside, and therefore has the effect of making it possible to detect leaks at low cost and with high precision.

[Brief explanation of the drawing]

The figure is a sectional view showing a schematic structure of an accumulator according to an embodiment of the invention. In the figure, 1 is an accumulator, 2 is a cylinder, and 3 is a cylinder.
1 is a floating piston, 4 is an oil chamber, 5 is a gas chamber, 8 is an end piece, 9 and 10 are sealing members, and 11 is a hood.

Claims (1)

[Scope of utility model registration request] In a piston-type accumulator, the cylinder interior is divided into an oil chamber and a gas chamber by a floating piston that freely moves therein, gas is sealed in the gas chamber, and pressure oil is introduced into the oil chamber.
A piston-type accumulator characterized in that the outer surface of the gas chamber including the seal portion is covered with a stretchable hood.