JPS6016565B2 - Leak test device using rotary valve type pressurization device - Google Patents

Description

Detailed Description of the Invention: To perform a leakage test on an air compressor with a capacity of about 3 to 6 liters used in refrigerators, etc., first introduce gas at a constant pressure into the test object, seal it, and then It is a usual method to test for leakage by measuring and detecting changes in the internal pressure after allowing the product to stand for a certain period of time.

The present invention relates to a leak test device that performs such a leak test as a continuous flow operation. When multiple test objects are sequentially connected to a compressed gas source and gas is injected into their interiors under pressure, and after a certain period of time has passed, each test object is sequentially connected to a pressure gauge and its internal pressure is measured. Because the pressure gas sealed in the test object is quite high pressure, the test object becomes hot until it is connected to the pressure gauge.
At the same time, the internal temperature also rises.

For this reason, there is a problem in that the gas inside the test object expands and acts in the direction of increasing the internal pressure, which counterbalances the reduced pressure due to leakage and adversely affects the detection of the internal pressure difference. SUMMARY OF THE INVENTION An object of the present invention is to provide a leak test device that can solve these problems and perform highly accurate leak tests. In order to solve the Kamitakuma problem,
This invention has the following configuration.

That is, the leak test device according to the present invention is installed in the inner region of the folded part of the conveyor where the test objects are sequentially transferred, and is driven to rotate around a certain point as the rotation center.
an annular rotary table with equal radial conduction paths;
A plurality of on-off valves are installed at each closing position on the outer periphery of the conduction path of the rotary table, and each of the test objects is connected via a connecting device; It has a first inlet to the closed inner circumference of the conduit passage, is connected to a pressure gauge, and sequentially introduces compressed gas at a predetermined pressure into the test object through the first inlet according to its transfer operation. A compressed gas introduction pipe and a second introduction port to the inner peripheral closed opening of the conduit passage of the rotary table are arranged downstream of the flow of the conveyor and at a predetermined angular interval from the first introduction port. In a leak test device that utilizes a rotary valve type pressurizing device comprising a pipe line having a port and a detection pressure gauge connected to the leakage test device, there is provided a leakage test device that utilizes a rotary valve type pressurizing device having a pipe line connected to a pressure gauge for detection. With respect to the inlet of No. 2, in a direction opposite to the rotation direction of the rotary table, at a position shifted by the equal angular pitch of the on-off valve,
A third introduction port is provided to the inner peripheral opening □ of the conduction path of the rotary table, a conduction path is provided that connects the third introduction port and the second introduction port, and a conduction path is provided in the conduction path. It is characterized by the inclusion of a differential pressure gauge. First, the principle and operation of this invention will be described.

FIG. 1 is a principle diagram for explaining the present invention. In the figure, 1 is a rotary table. Conduction passages 2 are provided radially in the rotary table at equal intervals in the radial direction, and an on-off valve 3 is attached to the outer end thereof over the entire circumference. 4 is on-off valve 3
The test object and the on-off valve can be easily connected with the couplers that are integrally connected to each other.

The conduction path 2, the on-off valve 3, and the coupler 4 are integrally connected and correspond to the rotation of the rotary table 1. It constitutes a primary valve. Next, 5 is a test object, and 6 is a conveyor. The test objects 5 are mounted on a conveyor 6 at equal intervals and are connected to a rotary valve at point A. P
o is a predetermined pressure gas source, and 7 is an inlet. At point A, the test object 5 is supplied with gas at a predetermined pressure via the inlet 7 and the rotary valve, and then the on-off valve 3 is closed and sealed at a constant pressure. Thereafter, the conveyor is gradually conveyed a certain distance within a certain period of time, and after a certain period of time, the internal pressure of the test object 5' is finally measured at point C using the detection pressure gauge G. The conduction path 10 including the detection pressure gauge G, with the corresponding on-off valve kept closed immediately before.
After adjusting the internal conduit space (dead space) to the specified pressure by replenishing pressure gas from the supply pressure gas source P to the specified pressure at our office, open the on-off valve to detect the internal pressure of the test object. However, prior to this final internal pressure detection, a conduction path 11 containing a differential pressure G2 is connected to the inlet 8 and 9, respectively, between the test object 5'' that has reached point B and the next test object 5''. , and an operation is inserted to detect the rhombic pressure of the internal pressure between both test objects 5' and 5''. By performing this differential pressure measurement, when the detected value of the differential pressure gauge between the test objects 5' and 5'' is small, there is little leakage from both, and both are affected only by background factors such as temperature changes. It is possible to eliminate the influence of background fluctuations.Also, when the detection value of the differential pressure gauge is large, it is predicted that there is a large leakage of one of the test objects.
By incorporating these results into the internal pressure detection that will be performed later, it becomes possible to perform accurate detection measurements. Note that the white arrows in the figure indicate the direction in which the rotary table and the conveyor are fed, and the black arrows indicate the direction in which the pressurized gas is supplied. Next, FIG. 2 is a plan view of a leak test apparatus using a rotary valve type pressurizing device showing an embodiment of the present invention. All the numbers used in the figure are the same as in Figure 1, but the on-off valve 3 is integrated with the coupler 4, and the rotary valve 3
It is expressed as In the embodiment, the test objects 5 are mounted on the conveyor 6 at intervals of 1. The conveyor feeds one skin per minute. The conveyor 6 is sent along an elliptical orbit as shown in the figure, but at position no. The test object 5 and the rotary valve 3 are connected at point A of 1, and a predetermined pressure gas source P
After the constant pressure of 15k9/flow is sealed from o,
Position No. Sent to 2. In this case, the corresponding rotary valve 3 is closed, but the two are fed sequentially while being connected by a flexible coiled hose made of nylon 11. After 15 minutes have elapsed in this way, the test object sealed with constant pressure gas at point A is placed at position No. in the figure. The point C of 16 is reached and becomes 5', and the adjacent and succeeding test object is at position No. 5'. 5'' at point B of 15.Here, the conductive path 11 containing the differential pressure gauge G2 and the test objects 5' and 5'' are connected through the inlets 8 and 9, respectively, and The corresponding on-off valves are opened and the differential pressure between the internal pressures within both test objects is detected by the differential pressure gauge G2. At this time, when the displayed value of the differential pressure gauge is large, it is predicted that there is a large leakage of one of the test objects, and this value can be used as a predictive reference value for the subsequent internal pressure detection. , and when the displayed value is small, there is little leakage in both cases, so it is only necessary to take into account the influence of the environment, such as temperature change, in the subsequent internal pressure detection. After this, the differential pressure detection step is completed by once closing the respective on-off valves.

Next, the process of detecting the internal pressure of the test object 5' is started, but just before that, pressure gas is introduced from the replenishment pressure gas source P into the dead space of the conduction path 10 including the detection pressure gauge G. Replenish until a constant pressure of 15k9/ground is reached. After this pressure replenishment is completed, the rotary valve of the test object 5' is opened, the internal pressure is detected by the detection pressure gauge ○, and the leakage state is detected by checking the detection result of the differential pressure gauge mentioned above. . After detecting the internal pressure at point C, the position No. moved 3 pitches (3 skins) by the conveyor. At point 19, the test object is connected to a reduced pressure source (vacuum pump) P2 via the lead-out path 12, the internal pressure is lowered to atmospheric pressure, and the leakage test is completed by disconnecting the rotary valve.

As mentioned above, in the first step, this device detects the intervention of errors caused by the environment, such as temperature changes in the pressurized and sealed test object, and in the second step, detects pressure fluctuations to eliminate these effects. By taking into account the measured internal pressure values, it becomes possible to carry out highly accurate leak tests extremely efficiently as a continuous process.

However, as an example of the second-stage internal pressure measurement method, there is a method in which the internal conduit space (dead space) is replenished with pressurized gas to the initial predetermined pressure to eliminate the influence of the previous internal pressure measurement. However, this is not an essential requirement, and it is of course possible to adopt other internal pressure measurement methods instead.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of a leak test device according to the present invention, and FIG. 2 is a plan view of a leak test device using a rotary valve type pressurizing device according to an embodiment of the present invention. 1...Rotating table, 2, 10, 11...
... Conduction path, 3 ... On-off valve or rotary valve, 4 ... Coupler, 5, 5', 5'' ...
・Test object, 6... Conveyor, 7, 8, 9...
...Inlet, 12... Outlet, ○. ...
...Detection pressure gauge, G2...Differential pressure gauge, Po・
...Predetermined pressure gas source, P. ...Replenishment pressure gas source, P2...Reduction source (vacuum pump). Figure 1 Figure 2

Claims (1)

[Claims] 1. An annular rotary table that is installed in the inner area of the folded part of the conveyor where the test objects are sequentially transferred, is driven to rotate around a fixed point, and has radial conduction paths evenly distributed; A plurality of on-off valves are attached to each opening position of the outer periphery of the conduction path of the table and each of the test objects is connected via a connecting device, and the conduction path of the rotary table is provided on the upstream side of the flow of the conveyor. A pressure gauge is connected to the test piece, and compressed gas at a predetermined pressure is sequentially introduced into the test object through the first introduction port according to the transfer operation. A compressed gas introduction pipe is arranged downstream of the flow of the conveyor, and at a position with a predetermined angular interval from the first introduction port. In the leakage testing device that utilizes a rotary valve type pressurizing device comprising a pipe line having an opening and a detection pressure gauge connected to the second A third inlet of the rotary table into the inner circumferential opening of the conduit passage is located at a position shifted by the equal angular pitch of the on-off valve in a direction opposite to the direction of rotation of the rotary table with respect to the inlet of the rotary table. A rotary valve pressurizing device is provided with a rotary valve type pressurizing device, characterized in that the third inlet port and the second inlet port are provided with a conduit passage that communicates with each other, and a differential pressure gauge is interposed in the conduit passage. Leak test equipment used.