JPS63249033A - Airtightness inspection apparatus for tank - Google Patents

Abstract

PURPOSE:To make the title apparatus simple and economical without using a water tank and to eliminate an inspection error, by locking a tank to be inspected to introduce air into the tank under pressure and inspecting airtightness on the basis of leak sound by an ultrasonic microphone before unlocking the tank. CONSTITUTION:The fuel tank T for a car is set to a working table 1 and the lock pin 3a of an electromagnetic type lock operating machine 3 is inserted in a lock hole to lock the tank T. Subsequently, compressed air of about 0.1kg/cm<2> is supplied to the tank T by a pump 7 and an airtightness test is performed on the basis of the leak sound in the vicinity of the mount part of the tank by an ultrasonic microphone 9M being a leak sensor. When the leak sound is generated, a buzzer and a rotating warning light 18 are operated and, after the finish of the inspection, the tank is unlocked. A series of these operations are automatically performed through a control box 12. As a result, since a water tank (water) is not used, inspection is made simple and economical and an inspection error can be eliminated.

Description

[Detailed description of the invention] [Industrial application field] The present invention applies to various products including fuel tanks for automobiles.

The present invention is used to inspect seed tanks, and specifically relates to a tank airtightness inspection device that checks whether there is a leak in the tank.

[Conventional technology]

For example, in the airtightness inspection (riichi check) of automobile fuel tanks, there is a primary inspection performed after welding the half-shell of the tank press-formed in half, and a level detector or similar device installed on the tank after welding. There is a secondary inspection that is performed after assembling various parts, and in both cases, airtightness is ensured by closing each opening and immersing a tank filled with air under water and visually checking for the presence or absence of air bubbles. I was checking the condition.

Therefore, a large aquarium filled with water is required for testing.
Moreover, since the tank must be operated by a person inside the aquarium, the work becomes very complicated, and there are problems such as the fact that the tank gets wet, which makes the work especially difficult in cold weather such as winter. Furthermore, since the bubbles generated from the leak source are often minute, there is a problem in that there is a high rate of inspection errors that result in overlooking the bubbles. In addition, regarding the secondary inspection conducted after parts have been assembled, the inspection area is limited to the part where the parts have been assembled and the surrounding area, and the entire tank is submerged in the same way as the secondary inspection. The inspection method of submerging the body inside the body is extremely unreasonable, and improvements in this point have been strongly desired.

[Problem that the invention seeks to solve]

Therefore, instead of the above-mentioned test method using a water tank.

One idea was to use the gas testing method used to check the airtightness of catalyst tanks in refrigerators and air conditioners.

However, this gas testing method, which involves pressurizing various gases such as chlorofluorocarbon gas into a tank and using a gas detector to detect the gas leaking from the leak source, is not only highly dangerous, but also involves the production of large amounts of gas. The running cost is high due to the use of gas leaks, and the equipment that accurately detects minute gas leaks is expensive, so it is not possible to use it to inspect high value-added products such as refrigerators and air conditioners. Even if there is, for example,
It was uneconomical and unsuitable for inspecting low-priced products such as automobile fuel tanks.

Therefore, the technical problem of the present invention is to improve the airtightness of the tank (
It is possible to test easily, safely and economically without using water), and to prevent the occurrence of test errors as much as possible.
To provide an airtightness inspection device for a tank that can send leak-free tanks to the market.

[Means for solving problems]

The measures taken in the present invention to solve the above technical problems are as follows.

(1) Provide a means to lock the tank placed on the workbench.

(2) Provide a means to pressurize air into the tank.

(3) Install a leak sensor that detects air leaks from the tank by using an ultrasonic microphone to catch the sound of air leaking from the leak source.

(4) Provide an alarm means that is activated when the leak sensor detects an air leak.

(5) Provide a means for releasing the above lock when the leak sensor does not detect air leakage.

[Effect] The above means works as follows.

■According to factor (1) above, once the tank is placed on the workbench, it is locked and cannot be removed until the leak inspection described later is completed, so the assembly of various parts is done on the workbench. By doing the above, it is possible to create a system in which all tanks are inevitably inspected for leaks, thereby eliminating omissions in inspections.

■According to the factor (2) above, since the leak test is performed by pressurizing air into the tank, the work is much simpler than the conventional test method that uses a water tank, and it also uses gas. It is cheaper and more economical than other testing methods, and
Enables safe inspection.

■Element (3) above allows the ultrasonic microphone to detect the leak sound of the tank in a non-contact manner and inspect its airtightness without attaching any sensors to the tank. It is an extremely simple operation that requires only close proximity to the object, thus making testing faster and more accurate.

■Element (4) above is that when an air leak is detected, a warning means such as a buzzer or lamp is automatically activated to notify the user of this, which prevents the occurrence of simple human inspection errors such as overlooking air leaks. It can be prevented.

■Element (5) above means that the tank placed on the workbench,
Unless air leak detection by the leak sensor is eliminated, that is, until all air leaks are completely repaired, it will continue to be locked to the workbench side, so even if an air leak is detected, you forget or neglect to repair it. This will solve the problem of providing defective products.

As described above, the above-mentioned technical problem can be solved by the above-mentioned means, and the problems of the conventional technology can be solved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the tank airtightness inspection device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of an apparatus according to the present invention, and the part indicated by reference numeral 1 is a mounting part 1a on which a tank T is mounted.
It is a workbench for airtightness inspection, which is equipped with a workbench.Of course, the shape of the workbench 1 changes depending on the shape of the tank T to be inspected. 2, 2 are limit switches provided on the above-mentioned mounting section 1a, and when the tank T set on the mounting section 1a turns on these limit switches 2, 2, a few seconds later (adjustable), the details are shown in Fig. 2. The pneumatic set or electromagnetic lock actuator 3 configured as described is activated to insert the lock pin 3a into the lock hole Tb formed in the welding joint Ta of the tank T, and the tank T is in the set state. It is designed to hold the

Next, in Figs. 1 and 3, 4 is an O-ring checker attached to the workbench 1, and an O-ring 5 for a gasket to be fitted into the mounting hole Tc of parts (level detector, etc.) of the tank T is inserted. When the checker 4 is inserted between the two guide plates 4a and 4b, the sensor 4s detects this and confirms the use of the O-ring 5. 6 is the above mounting hole T
This is a torque driver for tightening the screw Td that closes the screw Td, which is operated by compressed air sent from the pump 7 through the supply line 7a. Checker 4
When the sensor 4s detects the O-ring 5, a solenoid valve 63 is installed that energizes and opens the line, and the torque driver 6 is equipped with a hand switch 6 that turns the air on and off.
A is provided. Therefore, the torque driver 6 is
The ring checker 4 becomes operable only when it detects the insertion of the O-ring 5, thereby preventing forgetting to insert the O-ring 5.

Further, in FIG. 1, reference numeral 8 denotes a holder that is attached to the workbench 1 so as to be tiltable and rotatable. When the holder 8 is laid down horizontally as shown in the figure, the ultrasonic microphone 9M of the leak sensor can be connected to the screw Td. It can be brought close to the mounting opening Tc portion of the tank T that is blocked by.

In FIGS. 5 and 6, the leak sensor, indicated generally by the reference numeral 9, is a leak sensor 3 which is generated from a leak source in the tank T.
This is a leakage sound detection device for catching sounds in the 5 KHz frequency region, and is composed of the above-mentioned ultrasonic microphone 9M, an amplifier 9A, a leakage sound detection circuit 9D, a comparator 9C1, and a timer 9T. 9
It is determined whether or not a leak sound occurs during the time set by T (for example, 6 seconds).

Similarly, in FIG. 1, numeral 10 is a limit switch that is turned on when the holder 8 is folded down, and when this switch 10 is turned on, the solenoid valve 11s of the air supply hose 11 is opened. Reference numeral 11a denotes an inlet for introducing compressed air sent through the hose 11 into the tank T. When supplying air, the inlet 11a is connected to the hole Te of the tank T, and the other holes Tf... The pressure of the air supplied is 1,000 kA g (0,1 k
g/cm).

This is set by the air regulator and displayed on a pressure gauge (not shown).

1 and 4, 12 is a control box containing a control device 13 that controls each part of the present invention, and a power switch 14 is located on the front of this box 12.
A lamp 14L is provided, and a lamp 15a that lights up when the O-ring checker 4 detects the O-ring 5 and the solenoid valve 6S of the air driver 6 opens, and a lamp 15a that lights up when the O-ring checker 4 detects the O-ring 5 and the solenoid valve 6S of the air driver 6 opens, 30kg/c
Indicator lamp 15 consisting of a lamp 15b that lights up when the torque is tightened up to m), and a lamp 15c that lights up when the leak sensor 9 does not detect a leak sound, and when the set torque is reached and no leak sound is detected. Buzzer that sounds when 16. A flicker buzzer 17 is provided which sounds when a leak sound is detected. In addition, 18 is a flicker when the leak sensor 9 detects a leak sound.
The buzzer 17 and the patrol light 18 operate together with the buzzer 17, and the operation of the buzzer 17 and the patrol light 18 is stopped by pressing the reset button 19. 20 is a counter for counting the number of work pieces in the tank T.

Incidentally, the number of lamps 15b indicating that the set torque has been reached is provided as many as the number of screws Td to be tightened (six in the drawing). Further, the lock actuator 3 that locks the tank T in the set state is configured to be activated and unlocked when no leakage is observed and the lamp 15c lights up and the buzzer 16 sounds.

FIG. 5 is a block diagram showing a simplified electrical configuration of the present invention, in which each of the above-mentioned members is connected to the control device 13 to perform the above-mentioned operations, and the electrical configuration itself Since there is nothing new about this, the description of its circuit diagram will be omitted.

FIG. 7 is a flowchart illustrating the processing procedure when inspecting the airtightness of the tank T using the present invention, in which each of the above-mentioned operations is performed in the order of steps S1 to 813, and in step S14, the leak sensor 9 It is determined whether or not the leak sound has been detected, and if it is determined that the leak sound cannot be detected, that is, if it is determined that there is no leak and airtightness is maintained, steps S15 to 318 are performed. The process is executed and the inspection is completed. On the other hand, if it is determined in step S14 that a leak sound has been detected, the process in step S19 or S22 is executed, and the assembled O-ring 5 and screw T
After removing all parts d and inspecting the mounting opening Tc, the process from step S4 onwards is performed again to re-inspect the airtightness.

Incidentally, in the above-mentioned embodiment, the present invention was explained only in the case where the present invention was used for secondary inspection after each part was assembled, but the present invention also includes a means for bringing the leak sensor 9 close to all the welded parts of the tank T. Of course, by taking the following measures, it can also be used for subsequent inspections.

[Effects] The airtightness testing device for tanks according to the present invention is as described above, and since no water is used for testing, testing can be performed quickly and in a suitable environment, and
Since the leak sensor detects the leak sound and determines whether there is a leak, inspections can be performed more accurately and without mistakes compared to conventional inspection methods that visually check for the presence or absence of small bubbles generated from the leak source. The leak sensor is relatively inexpensive, and the entire device can be manufactured at low cost, making it economical. It is particularly useful for primary and secondary inspections of automobile fuel tanks, and for other refrigeration and air-conditioning equipment. It is suitable for use in leak inspection of various types of tanks.

[Brief explanation of drawings]

Fig. 1 is a front view illustrating the overall configuration of the tank airtightness inspection device according to the present invention, Fig. 2 is an enlarged view of the lock actuating mechanism, Fig. 3 is an enlarged perspective view of the O-ring checker, and Fig. The figure is a front view of the control box, FIG. 5 is a block diagram showing the electrical configuration of the present invention, and FIG. 6 is a block diagram of a leak sensor. FIG. 7 is a flowchart illustrating the testing procedure. 1 is the workbench, T is the tank, 3 is the lock actuator, 4 is the O-ring checker, and 6 is the torque screwdriver. 7 is a compression pump, 9 is a leak sensor, 9M is an ultrasonic microphone, 17 is a flicker buzzer, and 18 is a PA1 light. Patent applicant Shinwa Kogyo Co., Ltd. Figure 2 Figure 3 ■ Figure 4

Claims (1)

[Claims] A means for locking the tank placed on a workbench, a means for pressurizing air into the tank, and a leak sensor that detects air leaks in the tank by catching the sound of air leaking from the leak source with an ultrasonic microphone. An airtightness inspection device for a tank, comprising an alarm means that is activated when a leak sensor detects an air leak, and a means that releases the lock when the leak sensor does not detect an air leak.