JPS6226412B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leak testing method and apparatus for two independent spaces formed in an object to be measured such as an automobile engine part, which must not leak from each other.

In the parts that make up an automobile engine, two spaces are formed that must not leak into each other, such as a cooling water jacket and a lubricating oil passage in a cylinder block. In the prior art, leakage tests for these two spaces were conducted separately for each of these spaces. Therefore, when the speed of the production line is high, there is no time to perform leakage tests in two spaces at one location, and it becomes necessary to separately provide dedicated test equipment for each space on the line. As a result, various problems have arisen, such as an increase in equipment investment, an increase in the space occupied by the equipment, and a decrease in workability.

SUMMARY OF THE INVENTION Therefore, in view of the drawbacks of the prior art, it is an object of the present invention to provide a technique that allows simultaneous leakage testing of two locations to be measured.

The present invention will now be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 is an object to be measured, which has spaces S ₁ and S ₂ that are separated by a partition wall 101 and must not leak from each other. Also, 10
7 is the partition wall between the space S ₁ and the outside air, while 109
respectively indicate the partition wall between the space S ₂ and the outside air.

The reference container is represented by 12, has the same shape as the object to be measured 10, and has a space _T1 corresponding to one space _S1 of the object to be measured 10 and a space _S2 on the other side of the object to be measured 10.
It has a space T ₂ corresponding to . In this reference container 12, the spaces T ₁ and T ₂ are constructed so that they do not leak from each other through the partition wall 121 and from leak to the outside air through the partition walls 127 and 129.

According to the present invention, one space S ₁ of the object to be measured 10
and the corresponding space T ₁ of the reference container 12 and the differential pressure between the other space S ₂ of the object to be measured 10 and the corresponding space T ₂ of the reference container 12 as follows. means are provided. That is, 14 is a first pressure source that supplies test pressure via a first three-way valve 16. That is, the first three-way valve 16 is connected to one space _S1 of the object to be measured 10 via the first on-off valve 18, and at the same time is connected to one side of the reference container 12 via the second on-off valve 20. Connect to space T ₁ . A first differential pressure gauge 22 is disposed between the on-off valve 18 and the space S ₁ side and the on-off valve 20 and the space T ₁ side, and detects the pressure difference between the spaces S ₁ and T ₁ .

In addition to the first pressure source 14, a second pressure source 24 is provided, which controls the measured object 1 via a second three-way valve 26.
The other space S ₂ of 0 and the other space of the reference container 12
Supply pressure to T ₂ . That is, the second three-way valve 26
is connected to the space S ₂ via the third on-off valve 28 and, at the same time, to the space T ₂ via the fourth on-off valve 30 . Further, the second differential pressure gauge 32 is connected to the third valve 28.
It is located between the side closer to the space _S2 and the side closer to the space _T2 than the fourth valve 30, and detects the pressure difference between these spaces _S2 and _T2 .

According to the present invention, there is a difference in pressure between the first pressure source 14 and the second pressure source 24, and as a result,
As will be described later, leakage in the two spaces S ₁ and S ₂ of the object to be measured 10 can be detected at the same time. Hereinafter, for convenience, the first pressure source 14 will be described as having a higher pressure than the second pressure source. Note that 34 and 36 are pressure gauges.

To explain the leakage measurement method using the system shown in FIG.
By opening, the pressure from the first pressure source 14 enters the space S ₁ of the object to be measured 10 and the space T ₁ of the reference container 12 . On the other hand, by making the second three-way valve 26 conductive as shown in black and opening the third on-off valve 28 and the fourth on-off valve 30, the pressure from the second pressure source 24 is applied to the measured object. 10 space S ₂ and reference container 12 space T ₂ . When a steady state is reached, the pressure difference between the spaces S ₁ and T ₁ and between S ₂ and T ₂ disappears, and the differential pressure gauges 22 and 23 show zero. After this, all the on-off valves 18, 20, 28, and 30 are closed, and a differential pressure measurement cycle begins. First, the wall 10 of the object to be measured 10
7 and the outside air, the pressure in the space S ₁ decreases with time, while the pressure in the space T ₁ in the reference container
Since there are no leaks, the pressure is constant. Thus, the first differential pressure gauge 22 swings, thereby causing the wall 10 to
7 shows that there is a leak.

Next, if there is a leak between the wall 109 of the object to be measured 10 and the outside air, the pressure in the space S ₂ will decrease over time, whereas there is no leak in the space T ₂ of the reference container 12, so the pressure will remain constant. be. Thus, leakage in the wall 109 can be detected by the deflection of the second differential pressure gauge 32.

Further, if there is a leak in the wall 101 between the spaces S ₁ and S ₂ , the pressure in the space S on the high pressure side decreases and the pressure in the space S ₂ on the low pressure side increases. As a result, the spaces S ₁ and T ₁
The first differential pressure gauge 22 indicating the differential pressure between the spaces S 2 and T 2 swings to the decreasing side, and the second differential pressure gauge 32 indicating the differential pressure between the spaces S ₂ and T ₂ swings to the decreasing side.
swings to the increasing side. Thus, the presence of a leak in wall 101 is indicated.

As described above, according to the present invention, the spaces S ₁ and T ₁ and S ₂ are separated in the object to be measured 10 and the reference container 12.
By detecting the differential pressure of each of T ₂ by varying the supply pressure, it is possible to simultaneously measure the leakage of the spaces S ₁ and S ₂ that must not leak from each other in the object to be inspected. In this way, even lines with fast line takt times can be handled with one device.
Equipment costs and occupied space are reduced, and work efficiency is improved.

The embodiment of FIG. 2 uses a single factory-equipped compressed air source to implement the invention.
That is, the compressed air source 40 is connected to the pressure booster 42 on the one hand.
connected to the first three-way valve 16 on the high pressure side by
On the other hand, it is directly connected to the second three-way valve 26 on the low pressure side. The pressure increase device 42 includes a pressure increaser 44, a pressure smoothing tank 46, and a pressure reduction valve 48. Thus, the first three-way valve 16 is supplied with high pressure and the second three-way valve 26 is supplied with low pressure. The other configurations are the same as in FIG. 1. Also, there is no change in the effect.

In the embodiment shown in FIG. 3, when the measured pressure of the object to be measured 10 is low, a common pressure source 50 is connected to the first three-way valve 16 and the second pressure reducing valve 54 via the first pressure reducing valve 52. By connecting the pressure reducing valves 52 and 54 to the second three-way valve 26 through the pressure-reducing valves 52 and 54, high pressure is supplied to the first three-way valve 16 and low pressure is supplied to the second three-way valve 26. are doing. Further, a pressure reducing valve 70 is provided on the low pressure side. This pressure reducing valve 70
It functions to suppress the increase in pressure in chamber S ₂ and ensure the necessary differential pressure between chamber S ₂ and S ₁ when a large through-hole defect exists in chamber S 2 .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of the present invention, and FIG.
The figure shows the second embodiment, and FIG. 3 shows the third embodiment. 10...Measurement object, 12...Reference container, 14...
...Pressure source, 18, 20... Opening/closing valve, 22... Differential pressure gauge, 24... Pressure source, 28, 30... Opening/closing valve, 3
2...Differential pressure gauge, _S1 , _S2 ...Space of the object to be measured,
T ₁ , T ₂ ... Space in the reference container.

Claims (1)

[Claims] 1. A leakage test method for two spaces adjacent to each other in an object to be measured, wherein the differential pressure between one of the two spaces and one space of a reference container is measured in these spaces. At the same time, by introducing the first fluid pressure into the two spaces of the object to be measured and the other space of the reference container, the first fluid pressure is introduced into these spaces. A leakage measurement method comprising detecting by introducing a second fluid pressure having a value different from the fluid pressure. 2. A leak test device for two spaces adjacent to each other on a measured object, which allows a first fluid pressure to be introduced into one space of the measured object via a first opening/closing valve, and a second opening/closing valve. A second fluid that can be introduced into one of the spaces of the reference container through a valve, has a detector for the differential pressure between these one spaces, and further has a pressure value different from that of the first fluid. The pressure can be introduced into the other space of the object to be measured via the third on-off valve, and the pressure can be introduced into the other space of the reference container via the fourth on-off valve, and the pressure can be introduced into the other space of the reference container through the fourth on-off valve. Leakage measuring device with a detector for the differential pressure between.