SYSTEM FOR DETECTING LEAKS AND ASSOCIATED METHOD

Abstract

The present invention relates to a system (20; 20′) for detecting leaks for a part having a permeable zone, said system comprising: a test chamber (22, 22′) configured to receive the part to be tested; a device (24) suitable for varying the pressure in the test chamber and/or in the part to be tested; a measuring device (26) for measuring a physical quantity representative of the leak level; characterised in that said system (20; 20′) comprises a main pipe (30) configured to cooperate with the permeable zone of said part, said main pipe (30) having one end (30a) which communicates with the permeable zone, while the other end (30b) of said pipe (30) opens outside the test chamber (22; 22′).

Claims

1. System (20; 20′) for detecting leaks for a part having a permeable zone, said system comprising: a test chamber (22, 22′) configured to receive the part to be tested; a device (24) suitable for varying the pressure in the test chamber and/or in the part to be tested; a measuring device (26) for measuring a physical quantity representative of the leak level; characterised in that said system (20; 20′) comprises a main pipe (30) configured to cooperate with the permeable zone of said part, said main pipe (30) having one end (30a) which communicates with the permeable zone, while the other end (30b) of said pipe (30) opens outside the test chamber (22; 22′).

2. System according to claim 1, characterised in that it comprises an insert (28), said main pipe (30) being arranged in said insert (28).

3. System according to claim 1, characterised in that it comprises two seals (32a, 32b) ensuring tightness between the outside and the inside of the part to be tested.

4. System according to claim 3, characterised in that it comprises a secondary pipe (34) opening between the two seals (32a, 32b).

5. System according to claim 1, characterised in that the device (24) suitable for varying the pressure in the test chamber (22) and/or in the part to be tested is configured to vary the pressure according to a pressure gradient.

6. System according to claim 1, characterised in that the part to be tested is an electronic device (41, 41′) having an opening (41a, 41a′) sealed by a gas-permeable and liquid-tight membrane.

7. System according to claim 1, characterised in that the part to be tested is an electronic cigarette liquid cartridge (1) including a liquid tank (3), a suction tube (5) and a wick (7) disposed across said tube (5) and at least one of the ends of which is located in said tank (3).

8. System according to claim 1, characterised in that the measuring device (26) comprises a differential pressure sensor.

9. System according to claim 2, characterised in that leak detection is performed by means of the main pipe (30) connecting the measuring device (26) to said insert (28).

10. Leak detection method for a device according to claim 3, the first seal (32a) isolating the inside of the part to be tested from the inter-seal volume (37), the second seal (32b) isolating the inter-seal volume (37) from the outside of the part to be tested, characterised in that it comprises the following steps: establishing at least one similar first pressure (P.sub.1) in the test chamber (22; 22′) and the inter-seal volume (37); determining a first leak level (F.sub.1); establishing, in the inter-seal volume (37), a second pressure (P.sub.2) similar to the pressure of the main pipe (30) of the insert (28); determining a second leak level (F.sub.2); determining a leak level of the part (F.sub.p) based on the first (F.sub.1) and second (F.sub.2) leak levels.

11. Method according to claim 10, characterised in that there is a step of determining a leak correction factor.

12. Method according to claim 10, characterised in that the first leak level (F.sub.1) and/or the second leak level (F.sub.2) are determined based on at least one pressure interval.

Description

[0056] The invention will be understood better, and other aims, details, features and advantages thereof will emerge more clearly in the course of the following description of specific embodiments of the invention, given merely by way of illustration and not limitation, with reference to the appended drawings, wherein:

[0057] FIG. 1a is a very schematic representation of an electronic cigarette liquid cartridge;

[0058] FIG. 1b is a very schematic representation of an electronic cigarette liquid cartridge;

[0059] FIG. 1c is a very schematic representation of an electronic cigarette liquid cartridge;

[0060] FIG. 2 is a very schematic representation of the detection system according to the invention in a first application example;

[0061] FIG. 3 is an enlarged view of a subsection of the system in FIG. 2;

[0062] FIG. 4a is a very schematic representation of the detection system according to the invention in a second application example;

[0063] FIG. 4b is an enlarged very schematic view of a section of the system in FIG. 4a.

[0064] FIG. 2 is a very schematic representation of a detection system 20 according to the invention in a first application example, wherein said leak detection system 20 is used on a cartridge 1 as described with reference to FIGS. 1a to 1c.

[0065] Said system 20 thus comprises:

[0066] a test chamber 22 configured to receive the part to be tested, here said cartridge 1 (represented very schematically);

[0067] a device 24 suitable for varying the pressure in the test chamber 22;

[0068] a measuring device 26 for measuring a physical quantity representative of the leak level, such as a pressure gauge or a flow meter;

[0069] an insert 28 (or connection part) configured to cooperate with the zone of the cartridge 1 including a permeable zone.

[0070] The insert 28 is therefore inserted into the suction tube 5 of the cartridge 1 via one of the ends of said tube, while the other end of the tube is sealed by a sealing means, such as a cap.

[0071] As more specifically illustrated in FIG. 2, said insert 28 thus includes at least one main pipe 30 one end 30a of which communicates with the permeable zone of the part, while the other end 30b opens outside the test chamber 22.

[0072] More specifically, the main pipe 30 opens into the suction tube 5 of the cartridge preferably in the vicinity of the wick 7 of the cartridge 1, and therefore openings arranged in the wall 5a delimiting said tube 5 and communicating with the tank 3 (therefore at the zone of the part which is permeable).

[0073] Said insert 28 also includes: [0074] at least two seals 32a and 32b, referred to as first 32a and second 32b seals, configured to ensure the tightness between the outside and the permeable zone of said part 1, [0075] a secondary pipe 34 opening between the two seals; [0076] a main body 36 wherein the main 30 and secondary 34 pipes are arranged.

[0077] It will be noted that in the example represented in FIGS. 2 and 3, the insert 28 comprises two O-ring seals 32a and 32b which are mounted on the outer periphery of said insert 28 and disposed in contact with the wall 5a of the tube 5, but depending on the structure of the part to be tested, said seals 32a, 32b can be disposed differently. The space defined by said seals 32a and 32b, the wall 5a of the suction tube 5 and the main body 36 of the insert 28 defines a volume 37, referred to as inter-seal volume (said secondary channel 34 thus opens into the inter-seal volume 37).

[0078] The first seal 32a of the insert 28 isolates the inside of the cartridge to be tested from the inter-seal volume 37, while the second seal 32b isolates the inter-seal volume 37 from the outside.

[0079] It will be noted, moreover, that the presence of two seals ensures a certain tightness level, in spite of a poor surface condition of the wall 5a of said tube 5 (particularly due to the solder joint 11).

[0080] The insert 28 can also comprise a device 39 for holding the seals configured to hold the seals 32a and 32b in position and maintain a predetermined distance therebetween.

[0081] Furthermore, when it is sought to test the tightness level of a cartridge 1, a leak detection method comprising the following steps is applied:

[0082] Establishing a similar first pressure P.sub.1 in the test chamber 22 and the inter-seal volume 37, while the pressure in the suction tube 5 is for example kept at atmospheric pressure (this can be performed simply by means of the main pipe 30 opening outside the test chamber 22 and a valve).

[0083] Determining a first leak level F.sub.1, this determination is performed by measuring the variation of a physical quantity as a function of time, such as a pressure variation in the test chamber or at the suction tube 5 (for example, by means of the main pipe of the insert).

[0084] Establishing a second pressure P.sub.2 in the inter-seal volume 37 and in the zone of the part to be tested having a controlled leak, here the inside of the suction tube 5 of the cartridge 1 (this also limits the displacement of the first seal 32); it will be noted that the second pressure P.sub.2 is for example equal to atmospheric pressure.

[0085] Determining a second leak level F.sub.2, as above, this determination is performed by measuring the variation of a physical quantity as a function of time, such as a pressure variation in the test chamber 22 or at the suction tube 5 by means of the insert 28.

[0086] Determining a leak level of the part F.sub.p based on the first F.sub.1 and second F.sub.2 leak levels previously determined.

[0087] Thus, the first leak level F.sub.1 determine possibly includes the measurement of a leak associated with poor tightness at the seals 32a and 32b, particularly the first seal 32a, as well as other uncontrolled phenomena, seal displacements, temperature variation, etc.

[0088] While the second tightness level F.sub.2 determined measures a leak which does not include the leak at the first seal 32a.

[0089] During the determination of the leak level, said method can also comprise a step of determining a leak correction factor serving to correct the value of the first leak level F.sub.1 (for example, associated with a leak at the first seal).

[0090] According to the value of this correction factor, for example if the value of the first leak level is not modified by more than 5%, the measurement of the first leak level F.sub.1 is declared valid and is therefore considered as representative of the tightness level of the part tested.

[0091] If the correction factor is greater than a predetermined value, an alert is triggered, indicating to the user that there is a problem in the leak detection carried out, for example that the seal(s) are damaged or poorly positioned and that they should be better disposed or replaced.

[0092] The present detection method can also comprise an additional step wherein the correction factor is used to calculate a corrected leak level F.sub.1′ (said correction factor being applied to the first leak level F.sub.1), thus enabling the operator/user to be informed if the part tested meets the requested tightness criteria.

[0093] It will be noted moreover that the present method can be carried out with a set of discrete pressure values or with pressure intervals (or pressure gradients).

[0094] FIG. 4a, for its part, illustrates a leak detection system according to the invention in a second application example, wherein the leak detection system 20′ is used on an electronic device 41, 41′ having a permeable zone, such as an opening 41a, 41a′ sealed by a gas-permeable and liquid-tight membrane (for example, a GoreTex® membrane which is permeable to air and water-tight).

[0095] It will be noted that the same references have been used to designate similar elements.

[0096] Said system 20′ thus comprises:

[0097] first 22 and second test chambers 22′ configured to receive respectively a part to be tested 41 and a reference part 41′, here electronic devices;

[0098] a device 24 suitable for varying the pressure in the test chamber 22, 22′;

[0099] a measuring device 26 for measuring a physical quantity representative of the leak level (such as a pressure gauge or a flow meter);

[0100] inserts 28 cooperating respectively with each of the zones of the electronic devices respectively including a permeable zone, here the opening 41a, 41a′ sealed by a membrane.

[0101] As above, each of said inserts 28 has a main pipe, one end of which communicates with the permeable zone 41a, 41a′ of the part 41, 41′, while the other end opens outside the test chamber 22, 22′.

[0102] It will thus be noted that each of said inserts 28 has substantially the same structure as that described above with reference to FIGS. 2 and 3, except that when said insert 28 has two seals 32a and 32b, said seals 32a and 32b are disposed at the walls of the test chambers 22 and 22′ and/or between the walls of the insert 28 and the wall surrounding the permeable zone 41a, 41a′ of the part 41, 41′. The latter configuration is more specifically illustrated in FIG. 4b which is a very schematic and enlarged view of the contact zone between the main pipe 30 of the insert 28 and the permeable zone 41a.

[0103] The device 26 for measuring a physical quantity representative of the leak level comprises a differential pressure sensor and is connected to each of the inserts 28, more specifically by means of the main pipes 30 of the inserts 28.

[0104] The leak detection which is performed on the part to be tested can thus be performed in the same way as the method described above.

[0105] However, the leak detection method is advantageously performed by comparing the progression of a physical quantity representative of the leak level (such a pressure or a flow rate) between a part to be tested 41′ and a reference part 41, making it possible to avoid environment-related variations.

[0106] Nevertheless, in an alternative embodiment not shown, leak detection on an electronic device can be performed without a reference part as within the scope of the first application described above.

[0107] Advantageously, the first pressure P.sub.1 and/or the second pressure P.sub.2 can be pressure intervals and more specifically pressure gradients (i.e. a pressure variation per unit of time), preferably continuous and linear. This variation of the pressure over time can also be a succession of plateau pressures.