JP3113960B2 - Pinhole detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinhole detecting device for detecting a pinhole of a part.

[0002]

2. Description of the Related Art Conventionally, there is an air leak tester having the structure shown in FIG. 4 as a pinhole detecting device for detecting a pinhole of a component. The pinhole detecting means for the object to be inspected by this air leak tester is a master work having the same material and the same volume as the object to be inspected 51 and formed so as to prevent the compressed air filled therein from leaking. 52, the compressed air is simultaneously supplied to both the inspection object 51 and the master work 52 to form a sealed state, and then the inspection object 51 and the master work 52 are sealed.
The pressure difference of the workpiece 52 is measured, and if the pressure difference is equal to or more than a predetermined value, it is determined that the inspection object 51 has a pinhole.

As shown in FIG. 4, an inspection object 51 is clamped to an inspection tool 54 via a packing 53 by a clamper, while the master work 52 is fixed to a mounting tool 56. When the solenoid valve 57 is excited in this state, the test air from the test air source passes through the stop valve 58 and the air filter 59, is pressure-adjusted by the air regulator 60, and further passes through the solenoid valve 57 to the pilot valve 61. , Through the precision air filter 62, to the stop valve 63, to the air pipe connection port 64 of the inspection tool 54, and further through the hole 65 until the air chamber 66 of the inspection object 51 is filled.

On the other hand, the test air branched through the solenoid valve 57 passes through the pilot valve 67, passes through the precision air filter 68 and the stop valve 69, and passes through the master work 5.
The air is supplied from the air pipe connection port 70 until the air chamber 71 is filled.

After the test object 51 and the air chambers 66 and 71 of the master work 52 are filled with test air, the pressure oscillation of the air is eliminated and the pressure becomes stable (static pressure). And shut off the respective air inlet and outlet. If air leaks from the inspection object 51 in this state, a comparison is made based on the pressure of the master work 52.
That is, the differential pressure is measured by the differential pressure gauge 73, and when the differential pressure exceeds a predetermined value, the inspection object 51 is determined to be defective. On the other hand, when the differential pressure is equal to or less than the predetermined value, the inspection object 51 is good. Is determined.

[0006]

However, according to the pinhole detecting means of the object to be inspected by the above-mentioned conventional air leak tester, the air pressure used for the inspection medium is low.
At present, small-diameter foreign matter adhering to the inspection object 51 cannot be removed. Therefore, if a foreign matter is clogged in the pinhole of the inspection object 51, it cannot be detected even if there is a pinhole. There's a problem. To solve this problem, there is a means to perform an air leak test by increasing the air pressure. However, when foreign matter is discharged from the pinhole, the compressed air suddenly expands and an explosion occurs, which is extremely dangerous. However, there is a problem that it cannot be adopted in a production line. In the present invention, it is an object of the present invention to remove foreign matter clogged in a pinhole by using a high-pressure liquid as a test medium at a static pressure so that the presence of the pinhole can be detected. Things.

[0007]

The technical means for solving the above-mentioned problem is that a clamper is tightened and a test object is inserted through a packing.
The piste that adheres the inspection object to the inspection tool and is
Inspection of inspection object while pushing air out
The test liquid flows into the chamber space, and after this operation, the liquid flow
Block the air flow and slowly advance the piston to
Increase the pressure to the inspection pressure, and in this process,
If there is foreign matter in the sample, the foreign matter is
And the pinhole becomes conductive and the pressure drop
Occurs, the piston advances to the forward limit, and the inspection object is defective.
On the other hand, if the inspection object is a good product, the inspection room
Becomes high pressure, stops the piston operation and keeps high pressure
If the pressure drop is less than the specified value after the lapse of a predetermined time,
The test object is judged to be good and if the pressure drop is higher than the specified value
That is, it is configured to determine that the product is defective .

[0008]

Next, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a side view showing the overall configuration of the pinhole detecting device, FIG. 2 is a plan view, and FIG. 3 is a front view. As shown in the drawing, the inspection tool 1 is attached to a base 2, and the inspection object W is brought into close contact with the inspection tool 1 via a packing 3, so that a space for filling the liquid of the inspection medium is created.
The base 2 is provided with a clamper 4 for fastening the inspection object W to the inspection tool 1. In addition, inspection tool 1
Is provided with a piston 5 for generating a high liquid pressure. The high-pressure liquid pressure is generated by advancing the piston rod of the cylinder 7 and the piston 5 attached to the tip of the cylinder 7 in a state where the inspection chamber 6 is sealed. On the other hand, the base 2 has the inspection tool 1 and the clamper 4 placed thereon,
It is made to approach or separate from the inspection object W.

A flow rate supply source 8 for supplying a liquid as a test medium is provided, and a filter 9 is connected to the flow rate supply source 8 for removing foreign substances in the supply liquid. The filter 9 has an electromagnetic valve 1 for supplying and stopping the test liquid.
0 is connected. A visual gauge 11 is provided for measuring the pressure of the supply liquid while the solenoid valve 10 is controlled to open, and a pressure switch 12 for electrical detection is provided.
Is provided.

A check valve 13 is provided to prevent a back flow of the supply liquid when a high pressure is generated, and a pressure gauge 14 and a pressure switch 15 are provided for measuring the high pressure. Further, a discharge solenoid valve 16 is connected to the outlet pipe of the inspection tool 1 so as to open and close the inspection tool outlet pipe.

Next, the operation of the pinhole detecting device having the above configuration will be described. The base 2 is advanced by moving the base forward and backward cylinder 2A forward, and the clamper 4 is operated with the inspection tool 1 approaching the inspection object W, thereby fastening the inspection object W to the inspection tool 1. In this state, the electromagnetic valve 10 is excited to open the valve, and the test liquid flows into the test room 6 space of the test object W. At this time, the test liquid is supplied to the pipe connection port 17 of the test tool 1.
Through the hole 18 to enter the inspection room 6 space of the inspection object W,
While entraining and pushing out the air in that space, the holes 19
It reaches the pipe connection port 21 of the inspection tool 1 via the hole 20.
At this time, by energizing the discharge electromagnetic valve 16, the liquid in the aerated state is discharged. The solenoid valve 10 and the discharge solenoid valve 16
In this case, the air is expelled faster when the magnets are excited simultaneously.

A piston 5 for generating a high pressure
The air existing in the front space 22 is not completely exhausted and remains because the liquid flow in the room is disturbed. Then, in the liquid flowing state, the piston 5 is moved forward and backward by one reciprocation at a slow speed of about 3 m / min to discharge air. After this operation, the solenoid valve 1 is used to shut off the flow of liquid.
0 and the discharge solenoid valve 16 are simultaneously de-energized. Subsequently, the piston 5 is slowly advanced to generate a high pressure to increase the pressure in the inspection chamber 6 to the inspection pressure. If there is a foreign matter in the pinhole in the inspection object W in this process, the foreign matter is discharged by high-pressure liquid force, the pinhole becomes conductive, a pressure drop occurs, and the piston 5 advances to the forward limit.
The inspection object W is determined as a defective product.

On the other hand, if the inspection object W is a non-defective product, the pressure becomes high. When the pressure is detected by the pressure switch 15, the cylinder 7 is stopped and held on the spot to stop the operation of the piston 5 on the spot. . In this state, the inspection room 6 has secured a high static pressure. That is, if the pressure drop is equal to or less than a specified value after a predetermined inspection time has elapsed, the inspection object W is determined to be non-defective, and if the pressure drop is equal to or greater than the specified value, it is determined to be defective.

[0014]

As described above, according to the present invention, in order to detect a pinhole of an object to be inspected, a high-pressure liquid is used as a medium, and the presence of a pressure drop due to leakage is confirmed. -Even if foreign matter is clogged in the pinhole, the foreign matter is removed,
There is an effect that a correct judgment can be made as a defective product.

[Brief description of the drawings]

FIG. 1 is a side view and a hydraulic circuit diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a side view showing an overall configuration of a conventional pinhole detection device.

[Explanation of symbols]

 Reference Signs List 1 inspection tool 2 base 3 packing 4 clamper 5 piston 6 inspection room 7 cylinder 8 liquid supply source 9 filter 10 solenoid valve 11 visual gauge 12 pressure switch 13 check valve 14 pressure gauge 15 pressure switch 16 discharge solenoid valve 17 Pipe connection port (inlet) 18 hole (liquid passage) 19 hole (liquid passage) 20 hole (liquid passage) 21 pipe connection port (outlet) 22 space (front of piston)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 3/26

Claims (1)

(57) [Claims] (1) A clamper (4) is tightened through a packing (3).
The inspection object W is brought into close contact with the inspection tool 1 and
While pushing out the air by the advance of the piston 5
An inspection liquid is caused to flow into the inspection room 6 space of the inspection object W,
After the operation, shut off the flow of the liquid and slowly move the piston 5
To raise the pressure in the test room 6 to the test pressure,
In this process, when there is a foreign matter in the pinhole on the inspection object W
In the case, the foreign matter is discharged by high-pressure liquid power,
Conduction state, pressure drop occurs, piston 5 moves forward
Inspection object W is determined to be defective,
On the other hand, if the inspection object W is a good product, the inspection room 6 has a high pressure,
The operation of the piston 5 is stopped and maintained at a high pressure.
If the pressure drop is equal to or less than the specified value after the passage of
If the pressure drop is higher than the specified value
A pinhole detecting device characterized in that it is configured to make a determination .