JPS646466Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a flange joining device, for example, a flange joining device suitable for vacuum sealing.

Conventionally, a seal structure shown in FIG. 1 has been widely used in this type of device. In the figure, 1 is a vacuum duct, 2 is a gasket grooved flange provided on this duct, 3 is a mating flange without a groove, and 4
5 is a gasket groove, 5 is a gasket, and 6 is a tightening bolt for tightening the flanges 2 and 3 to crush the gasket 5.

In the above flange structure, the vacuum duct 1
In order to maintain a vacuum inside the gasket, it is necessary to collapse the gasket 5 to an appropriate amount. Therefore, by tightening the mating flange 3 with bolts 6 to the flange 2 into which the gasket is inserted, an appropriate crushing margin is obtained.

However, in the conventional vacuum seal flange structure shown above, the gasket is not visible after the flange is tightened, so the crushing margin cannot be confirmed, and the depth of the gasket groove cannot be increased due to the crushing margin. When tightening the flange in the horizontal direction, there are disadvantages such as the gasket falling off before the flange is tightened. In addition, the gasket groove and the mating flange side that comes into contact with it are machined with extremely high precision. For example, if a metal gasket is used as the gasket, the movement of the flange after the flanges are aligned can cause scratches on the surface of the flange that contacts the gasket. There are also disadvantages such as attaching.

This invention was made in order to eliminate the above-mentioned drawbacks, and a male side step is installed on one side of the opposing flanges that are joined by tightening and maintain airtightness between the inside and outside. and a female side step part that fits into the male side step part, and the outer diameter of the male side step part is formed to be approximately the same diameter as the inner diameter of the gasket fitted therein. The stepped portion is configured such that there is at least a gap between the end of the male stepped portion and the bottom of the female stepped portion when the gasket is fitted and tightened. An exhaust groove is provided in the circumferential direction on the cylindrical surface of either one of the gaskets in the vicinity of the gasket in order to easily detect leakage from the gasket portion during a leakage test of the tightening portion of the flange. By providing an axial exhaust groove with one end communicating with this circumferential exhaust groove and the other end opening in the gap, it is possible to easily and reliably seal the seal, and it is also essential for the seal part. The present invention provides a flange joint device that can easily perform leakage tests.

Hereinafter, this invention will be explained in detail with reference to the drawings showing one embodiment thereof. In Fig. 2, 1 is a vacuum duct, 7 is a flange provided on the duct 1,
Reference numeral 8 designates a mating flange, in which a male step is formed on the opposing surfaces of the flanges 7 and 8 to protrude from the opposing surface of one flange, for example, flange 7, and the other is fitted with a male step. A fitting spigot part 9 is formed, which is formed of a male step part provided on the opposing surface of the flange, for example, the flange 8. Here, the outer diameter of the male side stepped portion is configured to a size that allows the gasket 5 to be fitted into the inner diameter portion thereof. On the circumference of the male side step of the spigot part 9 of the flange 7, there is an annular exhaust groove that is an exhaust groove, one end of which communicates with the annular exhaust groove, and the other end of which is connected to the end face of the male side step and the bottom of the female side step. There is an axial exhaust groove that opens in the gap between the two.

In the above flange structure, when the gasket 5 is fitted to the male step of the spigot part 9 of the flange 7 and the mating flange 8 is brought close, the gasket 5
Before the flange 8 comes into contact with the flange 8, the fitting spigot part 9 is fitted, and the flanges 7 and 8 are positioned. Next, the gasket is tightened by tightening the flange 8 with the bolt 6.
Tighten the fitting spigot part until the end of the male step touches the bottom of the female step, or leave a small gap and then measure the gap G between the outer periphery between flanges 7 and 8 to tighten the gasket. The crushing amount can be measured from the outside, and the gap G can be tightened to a predetermined value.

In addition, the exhaust groove 1 provided in the fitting spigot part
0 and the exhaust groove 11 that communicates this with the inside of the vacuum duct 1 to quickly exhaust the gas existing in the fitting spigot part where gas tends to accumulate when the inside of the vacuum duct 1 is evacuated. I can do it.
Of course, the gas existing in the fitting spigot part is contained in the exhaust grooves 10, 11 and the exhaust grooves 10, 11.
Although the parts that are very close to the vacuum duct are well suctioned and exhausted, even the parts that are slightly away are fitted together via the exhaust groove 11 that opens into the vacuum duct 1 and the exhaust groove 10 that communicates with the exhaust groove 11. The suction of the spigot part is strong, and as a result, the fitting spigot part can be efficiently and quickly evacuated.

On the other hand, such airtight parts are usually subjected to a functional test after assembly to confirm their airtightness.

In this airtightness test, that is, a gas leakage test, gas leakage can be easily detected with the configuration of this invention. For example, when performing a helium leak test, the inside of the gasket is first evacuated, then helium gas is blown from the outside, and leakage of helium gas into the inside of the gasket is detected. In this case, if a fitting spigot part is provided as in the present invention, the helium gas that has entered from the gasket part will accumulate in the fitting spigot part.
However, in this invention, since the exhaust grooves 10 and 11 are provided, the detected gas that has entered the fitted spigot part from the outside is strongly attracted by the exhaust grooves 10 and 11. It can be easily introduced into the flange, making it easy to detect intruding gas, making it extremely effective for leak tests. Note that, on the contrary, the same effect can be obtained when the detection gas is confined within the duct and detected from outside the flange.

Further, as described above, the provision of the exhaust groove 11 is extremely effective not only for exhausting the fitting portion, but also for leakage testing of the flange joint portion.

Although the above embodiments have been shown for the flange structure of a vacuum seal, the above flange structure can be used not only for vacuum seals, but also for water seals and oil seals, as well as for leakage tests that are performed after the flange is assembled. At this time, gas pressure such as nitrogen or air is applied from the inside, and then a foaming agent such as soap liquid is applied from around the flange joint.
Also when checking for leakage of the pressurized gas, the configuration of the exhaust annular groove and the exhaust groove improves the leakage detection sensitivity and has the same effect as the above embodiment, and The same effect as in the above embodiment can be obtained when measuring the crushing amount of the gasket. Further, the exhaust groove of the fitting spigot part may be provided on the spigot side of the flange 8.

As described above, according to this invention, the male side step part is provided on one side of the facing surfaces of the opposing flanges that are joined by tightening and maintain airtight between the inside and outside, and the male side step part is on the other side. A female side step part is formed to fit into the male side step part, and the outer diameter of the male side step part is formed to be approximately the same diameter as the inner diameter of the gasket fitted therein, and the gasket is fitted therein. The stepped portion is configured such that there is at least a gap between the end of the male stepped portion and the bottom of the female stepped portion when the male stepped portion is tightened, and the gasket of either the male side stepped portion or the female stepped portion is Circumferentially on adjacent cylindrical surfaces,
In order to easily detect leakage from the gasket part during a leakage test of the tightening part of the flange, an exhaust groove is provided, and one end communicates with this circumferential exhaust groove and is connected to the above gap. An axial exhaust groove with the other end open makes it easy and reliable to position the flange, prevent the gasket from falling, and measure the gasket crushing amount after tightening the flange. The gas in the joint can be easily and reliably evacuated, and it is also extremely effective in leakage tests, making it more practical than conventional flange joining devices.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a conventional flange joining device for vacuum sealing, FIG. 2 is a vertical sectional view of a flange joining device for vacuum sealing according to an embodiment of this invention, and FIG.
The figure is a sectional view taken along the - line in FIG. 2. 1... Vacuum duct, 2... Flange with gasket groove, 3... Mating flange without groove, 4... Gasket groove, 5... Gasket, 6... Flange tightening bolt, 7... Fitting convex flange, 8...
... Fitting concave flange, 9... Fitting spigot part, 10, 11... Exhaust groove. In addition, in the drawings, the same reference numerals indicate the same or opposite parts.

Claims (1)

[Scope of utility model registration request] Opposed flanges that are joined by tightening and maintain airtightness between the inside and outside have a male side step on one side of the opposing surfaces, and a female side step that fits into the male side step on the other side. The outer diameter of the male stepped portion is formed to be approximately the same diameter as the inner diameter of the gasket fitted thereto, and the end of the male stepped portion is formed when the gasket is fitted and tightened. The step part is configured to have at least a gap between the bottom part of the male side step part and the bottom part of the female side step part. In order to easily detect leakage from the gasket part during leakage testing of the tightening part of the flange, an exhaust groove is provided.
A flange joining device characterized in that an axial exhaust groove is provided, one end communicating with the circumferential exhaust groove and the other end opening in the gap.