JPH03211435A - Device and method for testing airtightness of screw hole of semicylinder body - Google Patents

Abstract

PURPOSE:To conduct a test wherein an in-use state is incarnated by covering the semicylinder body which is fitted to a slidable table with a body to be tested and pushing up the table while engaging an airtight lid threadably with the screw hole and pressing it with an elastic cap. CONSTITUTION:The body W to be tested is superposed on the semicylinder body 3 right below a clamping device 5 and the airtight lid 4 is engaged threadably with the screw hole H of the body to be tested. Then the table 2 is moved and a pressing-up device 8 pushes up the body W to be tested together with the table 2; and the elastic cap 6 which is moved down is crimped to the airtight lid 4 and while a vacuum device sucks air upward, a pressure air sending device 9 sends pressure air to between the body W to be tested and semicylinder body 3 in the airtight state from below to applying pressure to a gap. Consequently, if the airtightness of the threadable engagement state of the air tight lid 4 is deficient, an alarm buzzer sounds. It is therefore decided that the tested body W is normal unless the buzzer sounds for a preset time, and the decision result at the actual site is high in matchability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an airtightness testing device and method for a semi-cylindrical body having a threaded hole in the center.

[Prior Art] The test object that is particularly targeted in this invention is, for example, when attaching another branch pipe to an existing gas pipe in a T-shape, the test object is a two-half pipe having an inner diameter equal to the outer diameter of the existing gas pipe. A hole with a diameter equal to the outside diameter of the branch pipe is bored in one side of the cylinder, a thread is cut into the inner surface of this hole, and the existing gas pipe is overlapped and covered, and the amphibious cylinder is attached to the split surface. Generally, the branch pipe is secured by tightening with a bolt and a nut, and a branch pipe with a thread cut in the end thereof is inserted at right angles into the threaded hole and screwed together to form a T-shaped branch part.

Of course, since this branch part forms part of the pipe line, there must be no gas leakage from here, and an elastic ring is installed between the existing gas pipe and the semi-cylindrical body placed on top. It must be kept airtight by inserting a seal. Also, there must be no gas leakage from the threaded holes, so liquid packing is applied to the surface of the female threaded holes to maintain airtightness. An airtightness test is required to confirm this kind of airtightness before leaving the factory, but in the past, the target test object, a semi-cylindrical body, was placed on a surface plate, and the center screw hole was The airtightness was determined by screwing on an airtight lid, applying air pressure inside, and visually inspecting with soapy water to see if there were any pressure leaks around the screw holes.

[Problem to be solved by the invention] However, with this method of airtightness testing, no pressure leaks could be detected during the witnessed test at the factory, and even though the airtightness test had been passed, it was necessary to carry out the on-site inspection. When actually performing piping work and ventilating the pipes, it is not uncommon to find gas leaking from the threaded connections, and end up having to redo the emergency work. Although various studies have been conducted to determine the cause of this problem and countermeasures have been taken, in the end, it is thought that the biggest cause is that the airtightness test at the factory differs from the actual construction conditions. In other words, even if the semi-cylindrical body is left still on a surface plate in a factory and the threaded part is tested for airtightness, it will not necessarily match the connection condition at the site, and it may be that another element has leaked out. be understood. The largest of these is the case where static pressure can be applied with a single semi-cylindrical body, and the case where static pressure can be applied by a single semi-cylindrical body, and the case where the remaining semi-cylindrical body is placed over the gas pipe at the site and applied from below, and both are tightened with the split surface. This is the difference when receiving atmospheric pressure. In the latter case, plastic deformation appears in some parts because the split surface is restrained, and this influence subtly extends to the threaded part, leading to a result that is different from the threaded state when the single piece is released. it is conceivable that. However, it is extremely difficult to realize this element in a normal airtight test facility, and even if it were to be done, the work would be too complicated.

Furthermore, even if it is only the former airtight test of a single unit, it is necessary to carry in and out the test unit, seal the bottom and sides with blind boards, etc. in order to apply air pressure inside the unit.
Variations in test conditions due to individual differences among workers when screwing airtight lids into screw holes, and the risk of oversight due to differences in workers' ability to detect pressure leaks when applying air pressure, etc.
This is an unavoidable problem as it is a pitfall of exams that rely on human language. In order to solve the above-mentioned problems, the present invention makes it possible to conduct an airtightness test at a factory test site under conditions that most closely resemble the on-site construction work, and to obtain highly reliable results. The purpose of the present invention is to provide a testing device that is automated and greatly reduces labor and time compared to conventional methods, and a testing method using the device.

[Means for Solving the Problem] The semi-cylindrical body screw hole airtightness test device according to the present invention includes a table that can freely slide on a horizontal table, and a semi-cylindrical body that fits on the table and has a hole penetrated in the center. a tightening device that screws the airtight lid into the screw hole of the test object, which is installed vertically from above; A device for pushing upward, a vacuum device for sucking upward from inside the cap, a pressure air device for pressurizing upward from inside the semi-cylindrical body, and electricity built in so that each of the above devices operates according to a predetermined procedure. The above problem was solved by consisting of a circuit.

[Operation] The operation of the present invention will be explained based on FIG. 1 and FIG. 2 showing an embodiment. In each figure, a table 2 which can slide on a horizontal platform 1 is mounted, onto which a semi-cylindrical body 3 having a circular hole in the center is fitted. The table 2, the semi-cylindrical body 3, and the test object W placed on the semi-cylindrical body 3 can integrally slide on the table and change their positions in the lateral direction. A tightening device 5 for screwing the airtight lid 4 into a screw hole H drilled in the center of the test object is vertically installed above the position where the test object W is first set, and a tightening device 5 is installed vertically above the position where the test object W is set. A vacuum device @ 7 that presses the elastic cap 6 onto the covered airtight lid 4 and sucks air upward; and a push-up device 8 that is disposed below the vacuum device and pushes the table upward.
and a pressurized air device 9 that fits through the table 2 and connects to a flexible air supply pipe that extends downward.

The test object W is first placed on the semi-cylindrical body 3 in an airtight manner directly below the tightening device 5 as shown in FIG. In order to keep the image airtight, specifically, it is preferable to insert an elastic ring packing P around the inner surface of the screw hole H of the test object W to block air circulation by the weight of the test object W. Here, the upper tightening device 5 comes down from above and screws the airtight M4. When the screwing is completed, the tightening device moves upward again, and the table 2 slides sideways to another position on the table.

Here, the table and the test objects loaded thereon are pushed upward together with the table by the operation of the push-up device 8, and the collar flange F forming the split surface of the semi-cylindrical body is in a restrained state. Here, a vacuum device 7 with an elastic cap 6 at its tip descends and presses onto the airtight lid 4, and the vacuum device operates to suck air upward, creating an airtight state. Pressure air is sent between the test object W and the semi-cylindrical body 3 from below by a pressure air device 9 to pressurize the gap S. If the air pressure in the screwed state of the air pressure 14 is insufficient, the pressure will pass through the airtight lid from the pressurized gap S and enter between the airtight lid and the elastic cap that is crimped, reducing the degree of vacuum. This is detected and the alarm buzzer is activated. Therefore, if the buzzer does not sound for a preset period of time, the test object currently placed on the table is determined to have passed the airtightness test.
This judgment is highly reliable and will not fail even during on-site construction.

After passing or failing the test, stop the vacuum and pressurization, raise the elastic cap, slide the table back to its original position, lift only the test object with a crane, etc., and carry it out to complete the airtightness test. .

[Example] An example will be described in more detail while avoiding duplication with the description in the previous section.

FIG. 3 is a perspective view of the embodiment, showing the same stage as FIG. A long groove 21 is carved into the upper surface of the table 2, and the semi-cylindrical body 3 is fitted into this long groove and fixed. The table is moved in the lateral direction by rotation of table rollers 11 arranged on the side surface of the table 1. An air pump 12 is installed under the table 1 and is connected to flexible tubes 14, 15, 16 via a switching lever 13 so as to be able to switch between the tightening device 5, the pushing device 8 and the pneumatic device 9. As shown in the opening of FIG. 1, the tightening device 5 on which the flexible tube 14 is disposed includes a spring 51 for pressing, a driving section 52, and a cap 53 that grips and rotates the airtight lid 4. The push-up device 8 on which the flexible tube 15 is arranged includes a cylinder 81 and a ram 82.
The table 2 is lifted upward by the above steps, but the upper frame 17 with a step protrudes above the table 1 like an eaves, and the collar flange F protruding from the split surface of the test object W that has been pushed up is 1. It is pressed against the step and stops at this height, receiving a restraining force.

The pneumatic device 9 in which the flexible tube 16 is disposed is connected to an air pipe 91 directly connected to a round hole 31 penetrating through the center of the semi-cylindrical body 3.

On the other hand, the tip of the vacuum device 7 is made up of a rubber elastic cap 6 and a spring 61 that presses it downward, and is connected to a vacuum tank 72 via a flexible tube 71, which houses a vacuum pump 73 and externally. An alarm buzzer 74 is attached to the.

[Effects of the Invention] The present invention has the above-mentioned configuration and produces an effect, so an airtightness test that almost faithfully embodies the special usage conditions of the test object is performed, and the pass/fail judgment can be made on-site. The results are highly consistent and can be trusted. Furthermore, the airtightness test itself is automated, significantly reducing the burden on workers and significantly improving test work efficiency, which also brings about the secondary effect of lowering costs.

[Brief explanation of drawings]

Figure 1A is a front view and side view showing the embodiment of the present application;
Figure A is a front view and side view showing different states of the same embodiment, and Figure 3 is a perspective view of the embodiment. 1...stand, 2...table, 3...semi-cylindrical body, 4
...Airtight lid, 5. Tightening device, 6. Elastic cap, 7. Vacuum device, 8. Pushing device, 9.
... Pressure device, W ... Test object, H ... Screw hole, F
...Trim flange, S...Gap, P...Ring packing

Claims (2)

[Claims] (1) A table that can slide freely on a horizontal platform, a semi-cylindrical body that fits into the table and has a hole in the center, and an airtight lid that is hung from above and is tightened by screwing it into the screw hole of the test object. a device for placing and pressing an elastic cap vertically disposed on the airtight lid at another position on the table while pushing the table upward; and a vacuum device for sucking upward from inside the cap; A screw hole airtight test device for a semi-cylindrical body, comprising a pressure air device that pressurizes the semi-cylindrical body upward from the inside, and an electric circuit built into each of the devices so that each device operates according to a predetermined procedure. (2) A semi-cylindrical body with a hole in the center is fitted onto a horizontally movable table, and a semi-cylindrical body with a split flange, which is the test object, with a screw hole drilled in the center is fitted onto the semi-cylindrical body with a hole in the center. Cover them airtightly, screw an airtight lid into the screw hole, slide the table together on the table, restrain the split flange surface at a predetermined position, and cap with an elastic cap that presses against the airtight lid from above, A semi-cylindrical body characterized in that pressure is applied from the bottom through the semi-cylindrical body hole and pressure is reduced from the top of the elastic cap, and an alarm is automatically issued when the pressure balance is lost within a predetermined time. Screw hole airtightness test method.